{
  description = "personal NixOS configurations";

  inputs = {
    nixpkgs.url = "github:nixos/nixpkgs/nixos-24.11";

    home-manager = {
      url = "github:nix-community/home-manager/release-24.11";
      inputs.nixpkgs.follows = "nixpkgs";
    };

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

    treefmt-nix = {
      url = "github:numtide/treefmt-nix";
      inputs.nixpkgs.follows = "nixpkgs";
    };

    flake-utils.url = "github:numtide/flake-utils";
    pre-commit-hooks = {
      url = "github:cachix/pre-commit-hooks.nix";
      inputs.nixpkgs.follows = "nixpkgs";
    };
    devshell.url = "github:numtide/devshell";
    devshell.inputs.nixpkgs.follows = "nixpkgs";
  };

  # Output config, or config for NixOS system
  outputs =
    { self
    , nixpkgs
    , darwin
    , flake-utils
    , pre-commit-hooks
    , devshell
    , ...
    }@inputs:
    flake-utils.lib.eachDefaultSystem (system:
    let
      pkgs = import nixpkgs {
        inherit system;
        overlays = [ devshell.overlays.default ];
      };
      mkSystem = import ./nix/lib/mkSystem.nix { inherit nixpkgs inputs; };
    in
    {
      checks = {
        pre-commit-check = pre-commit-hooks.lib.${system}.run {
          src = ./.;
          hooks = {
            nixpkgs-fmt.enable = true;
            check-merge-conflicts.enable = true;
            end-of-file-fixer.enable = true;
          };
        };
      };

      devShells.default = pkgs.devshell.mkShell {
        packages = with pkgs; [ just ];
        env = [{
          name = "DEVSHELL_NO_MOTD";
          value = "1";
        }];
      };

      # a VM running on the MacBook Air
      nixosConfigurations.vm-aarch64 = mkSystem "vm-aarch64" {
        system = "aarch64-linux";
        user = "fcuny";
      };

      # a VM running on the synology DS923+
      nixosConfigurations.vm-synology = mkSystem "vm-synology" {
        system = "x86_64-linux";
        user = "fcuny";
      };

      # my personal MacBook Air
      darwinConfigurations.macbook-air-m2 = mkSystem "macbook-air-m2" {
        system = "aarch64-darwin";
        user = "fcuny";
        darwin = true;
      };

      # my work MacBook Pro
      darwinConfigurations.macbook-pro-intel = mkSystem "macbook-pro-intel" {
        system = "x86_64-darwin";
        user = "fcuny";
        darwin = true;
      };
    });
}