Flake-parts example

{
  description = "Nix flake";

  inputs = {
    nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
    flake-parts.url = "github:hercules-ci/flake-parts";
  };

  outputs = inputs: inputs.flake-parts.lib.mkFlake { inherit inputs; } {
    systems = [ "x86_64-linux" ];
    perSystem = { pkgs, self', ... }: {

      packages.default = pkgs.vim;

      devShells.default = pkgs.mkShell {
        packages = with pkgs; [
          self'.packages.default
        ];
      };

    };
  };
}

Activate the development shell

$ nix develop

Build the package

$ nix build

Run the package

$ nix run