{
  inputs = {
    nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
    flake-utils.url = "github:numtide/flake-utils";
    nixpkgs-master.url = "github:NixOS/nixpkgs/master";
    home-manager = {
      url = "github:nix-community/home-manager/master";
      inputs.nixpkgs.follows = "nixpkgs";
    };
  };
  #inputs.agenix.url = "github:ryantm/agenix";
  inputs.firefox-addons.url = "gitlab:rycee/nur-expressions?dir=pkgs/firefox-addons";
  inputs.nixos-hardware.url = "github:NixOS/nixos-hardware/master";
  inputs.nixvim = {
    # If you are not running an unstable channel of nixpkgs, select the corresponding branch of nixvim.
    url = "github:nix-community/nixvim/22b587f3dc5c040eb1916aa2a67868f1918d9d17";

    inputs.nixpkgs.follows = "nixpkgs";
  };

  outputs = inputs @ {self, nixpkgs, nixpkgs-master, firefox-addons, home-manager, nixos-hardware, nixvim, ...}: let
    lib = nixpkgs.lib;
    util = (import ./overlays/util.nix {} {}).util;
    system = "x86_64-linux";
    pkgs = import nixpkgs { inherit system; overlays =  
      util.nixFilesIn ./overlays; }; 
  in  {
    nixosConfigurations = pkgs.util.mapHostAttrs (host: host) (host: lib.nixosSystem {
      inherit system;
      modules = [ 
	./hosts/${host} 
      ];
      specialArgs = { inherit inputs; };
    });
  };
}