{
  description = "Minimal static photo gallery with Atom feed and upload API";

  inputs = {
    nixpkgs.url     = "github:NixOS/nixpkgs/nixos-unstable";
    flake-utils.url = "github:numtide/flake-utils";
  };

  outputs = { self, nixpkgs, flake-utils }:
    flake-utils.lib.eachDefaultSystem (system:
      let
        pkgs = nixpkgs.legacyPackages.${system};
      in {
        packages.default = pkgs.buildGoModule {
          pname   = "photogallery";
          version = "0.1.0";
          src     = self;

          # Run `go mod tidy` to generate go.sum, then `nix build`.
          # Nix will fail and print the correct hash — paste it here.
          vendorHash = "sha256-SxQDRProQtauWXPvPzbZZChLQd0iey9hnXFLiPYTS98=";

          meta = with pkgs.lib; {
            description = "Minimal static photo gallery";
            license     = licenses.mit;
            mainProgram = "photogallery";
            platforms   = platforms.linux;
          };
        };

        devShells.default = pkgs.mkShell {
          packages = [ pkgs.go pkgs.gopls pkgs.gotools ];
        };
      }
    ) // {
      nixosModules.default = import ./module.nix self;

      # Lets consumers add photogallery to their pkgs without
      # pulling in the full flake module.
      overlays.default = _final: _prev: {
        photogallery = self.packages.${_final.system}.default;
      };
    };
}