{
  outputs = { self, ... }: let
    inherit sources = import ./npins;
    inherit (sources) nixpkgs flake-parts nixops4 nixops4-nixos git-hooks;
    pkgs = import nixpkgs;
    inherit (pkgs) lib;
    flake-parts-lib = import "${flake-parts}/lib.nix" { inherit lib; };
  in flake-parts-lib.mkFlake { inherit self; } {
      systems = [
        "x86_64-linux"
        "aarch64-linux"
        "x86_64-darwin"
        "aarch64-darwin"
      ];

      imports = [
        (import "${git-hooks}/flake-module.nix")
        (lib.importApply "${nixops4}/nix/flake-parts/flake-parts.nix" { inherit self; })

        ./infra/flake-part.nix
        ./services/flake-part.nix
      ];

      perSystem =
        {
          config,
          pkgs,
          lib,
          ...
        }:
        {
          formatter = pkgs.nixfmt-rfc-style;

          pre-commit.settings.hooks =
            let
              ## Add a directory here if pre-commit hooks shouldn't apply to it.
              optout = [ "npins" ];
              excludes = map (dir: "^${dir}/") optout;
              addExcludes = lib.mapAttrs (_: c: c // { inherit excludes; });
            in
            addExcludes {
              nixfmt-rfc-style.enable = true;
              deadnix.enable = true;
              trim-trailing-whitespace.enable = true;
              shellcheck.enable = true;
            };

          devShells.default = pkgs.mkShell {
            packages = [
              pkgs.nil
              (pkgs.callPackage "${agenix}/pkgs/agenix.nix" {})
              pkgs.openssh
              pkgs.httpie
              pkgs.jq
              # exposing this env var as a hack to pass info in from form
              (
                (pkgs.callPackage "${nixops4}/package.nix" {
                  # nixops4-cli-rust = config.packages.nixops4-release; # https://github.com/nixops4/nixops4/tree/main/rust/nixops4
                  # nixops4-eval = config.packages.nixops4-eval-release; # https://github.com/nixops4/nixops4/tree/main/rust/nixops4-eval
                })
                .overrideAttrs {
                  impureEnvVars = [ "DEPLOYMENT" ];
                }
              )
            ];
            shellHook = config.pre-commit.installationScript;
          };
        };
    };
}