{
  description = "music-light: dev environment (Python + playerctl) for NixOS/Nix";

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

  outputs = { self, nixpkgs }:
    let
      systems = [
        "x86_64-linux"
        "aarch64-linux"
      ];

      forAllSystems = f: nixpkgs.lib.genAttrs systems (system: f system);
    in
    {
      devShells = forAllSystems (system:
        let
          pkgs = import nixpkgs { inherit system; };

          # Use a stable Python version with good binary coverage for Pillow.
          py = pkgs.python312.withPackages (ps: [
            ps.requests
            ps.pillow
          ]);
        in
        {
          default = pkgs.mkShell {
            packages = [
              py
              pkgs.playerctl
            ];

            shellHook = ''
              echo "music-light devShell ready: $(python --version)"
            '';
          };
        });
    };
}