{
  description = "personal NixOS configurations";

  inputs = {
    nixpkgs = {
      type = "github";
      owner = "NixOS";
      repo = "nixpkgs";
      ref = "nixos-23.05";
    };

    futils.url = "github:numtide/flake-utils";

    home-manager = {
      type = "github";
      owner = "nix-community";
      repo = "home-manager";
      ref = "release-23.05";
      inputs = {
        nixpkgs.follows = "nixpkgs";
      };
    };

    darwin = {
      url = "github:lnl7/nix-darwin";
      inputs.nixpkgs.follows = "nixpkgs";
    };

    pre-commit-hooks = {
      type = "github";
      owner = "cachix";
      repo = "pre-commit-hooks.nix";
      ref = "master";
      inputs = {
        flake-utils.follows = "futils";
        nixpkgs.follows = "nixpkgs";
        nixpkgs-stable.follows = "nixpkgs";
      };
    };
  };

  # Output config, or config for NixOS system
  outputs = inputs@{ self, darwin, home-manager, ... }:
    let
      myLib = import ./nix inputs;
      lib = inputs.nixpkgs.lib // builtins;
      supportedSystems = [ "aarch64-darwin" ];
      forAllSystems = lib.genAttrs supportedSystems;

      # Nixpkgs instantiated for supported system types.
      nixpkgsFor = forAllSystems (system:
        import inputs.nixpkgs {
          inherit system;
          config = { allowUnfree = true; };
        });
    in
    {
      templates = import ./templates;

      checks = forAllSystems (system:
        let pkgs = nixpkgsFor.${system};
        in
        {
          pre-commit-check = inputs.pre-commit-hooks.lib."${system}".run {
            src = ./.;
            hooks = {
              nixpkgs-fmt.enable = true;
              trailing-whitespace = {
                enable = true;
                entry =
                  "${pkgs.python3Packages.pre-commit-hooks}/bin/trailing-whitespace-fixer";
                types = [ "text" ];
              };

              end-of-file-fixer = {
                enable = true;
                entry =
                  "${pkgs.python3Packages.pre-commit-hooks}/bin/end-of-file-fixer";
                types = [ "text" ];
              };

              check-executables-have-shebangs = {
                entry =
                  "${pkgs.python3Packages.pre-commit-hooks}/bin/check-executables-have-shebangs";
                types = [ "text" "executable" ];
              };

              check-json = {
                enable = true;
                entry = "${pkgs.python3Packages.pre-commit-hooks}/bin/check-json";
                types = [ "json" ];
              };

              check-toml = {
                enable = true;
                entry = "${pkgs.python3Packages.pre-commit-hooks}/bin/check-toml";
                types = [ "toml" ];
              };

              check-yaml = {
                enable = true;
                entry = "${pkgs.python3Packages.pre-commit-hooks}/bin/check-yaml --allow-multiple-documents";
                types = [ "yaml" ];
              };

              shellcheck = {
                enable = true;
                files = "\\.sh$";
                types_or = [ "file" ];
              };
            };
          };
        });

      devShells = forAllSystems (system: {
        default = inputs.nixpkgs.legacyPackages.${system}.mkShell {
          name = "fcuny-configuration-on-${system}-system";
          buildInputs = with inputs.nixpkgs.legacyPackages.${system}.pkgs; [
            gitAndTools.pre-commit
            nixfmt
            nixpkgs-fmt
            rnix-lsp
            home-manager
            git
            nixos-rebuild
          ];
          inherit (self.checks.${system}.pre-commit-check) shellHook;
        };
      });

      packages = forAllSystems (system:
        let pkgs = nixpkgsFor.${system};
        in
        {
          inherit (inputs.futils.lib) filterPackages flattenTree;
          tools = import ./tools { inherit pkgs; };
        });

      darwinConfigurations = {
        "mba-fcuny" = darwin.lib.darwinSystem {
          system = "aarch64-darwin";
          modules = [
            home-manager.darwinModules.home-manager
            ./hosts/mba
          ];
        };
      };
    };
}