{
  # talk — Sprach-Ausgaben für Skripte und KI-Agenten.
  #
  # Nutzung in einer NixOS-/Home-Manager-Konfiguration:
  #   inputs.talk.url = "git+https://code.m3ta.dev/m3tam3re/talk";
  #   environment.systemPackages = [ inputs.talk.packages.${system}.talk ];
  # oder als Overlay: nixpkgs.overlays = [ inputs.talk.overlays.default ];
  #
  # Dieses Flake ersetzt langfristig m3ta-nixpkgs talk/crunch (bash + mpv).
  description = "talk — Voice-Notifications für Skripte und KI-Agenten (ein Binary, Daemon mit Queue)";

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

  outputs = { self, nixpkgs }:
    let
      systems = [ "x86_64-linux" "aarch64-linux" "x86_64-darwin" "aarch64-darwin" ];
      forAll = f: nixpkgs.lib.genAttrs systems (system: f nixpkgs.legacyPackages.${system});
      version = if self ? shortRev then "0.0.0-${self.shortRev}" else "0.0.0-dirty";
      mkTalk = pkgs: pkgs.buildGoModule {
        pname = "talk";
        inherit version;
        src = self;
        subPackages = [ "cmd/talk" ];
        # Nach Änderungen an go.mod/go.sum neu setzen: `nix build` nennt den
        # erwarteten Hash.
        vendorHash = "sha256-CbF3juTA7V05hh1ElKKACddsCn4bIPeLZxsz2EZxs9I=";
        env.CGO_ENABLED = 0;
        ldflags = [ "-s" "-w" "-X" "main.version=${version}" "-X" "main.commit=${self.shortRev or "dirty"}" ];
        # Prozessgrenzen-Tests starten Daemons und binden Ports — nicht in der Sandbox.
        doCheck = false;
        # Audio: oto spricht PulseAudio/PipeWire direkt (reines Go) und fällt auf
        # ALSA zurück, das es zur Laufzeit per dlopen lädt — auf NixOS nur
        # auffindbar, wenn wir es in den Pfad legen. OS-Stimme: espeak-ng.
        nativeBuildInputs = pkgs.lib.optionals pkgs.stdenv.isLinux [ pkgs.makeWrapper ];
        postInstall = pkgs.lib.optionalString pkgs.stdenv.isLinux ''
          wrapProgram $out/bin/talk \
            --prefix LD_LIBRARY_PATH : ${pkgs.lib.makeLibraryPath [ pkgs.alsa-lib ]} \
            --prefix PATH : ${pkgs.lib.makeBinPath [ pkgs.espeak-ng pkgs.libnotify ]}
        '';
        meta = with pkgs.lib; {
          description = "Voice-Notifications für Skripte und KI-Agenten";
          homepage = "https://code.m3ta.dev/m3tam3re/talk";
          license = licenses.mit;
          mainProgram = "talk";
          platforms = platforms.unix;
        };
      };
    in
    {
      packages = forAll (pkgs: rec {
        talk = mkTalk pkgs;
        default = talk;
      });

      apps = forAll (pkgs: rec {
        talk = { type = "app"; program = "${mkTalk pkgs}/bin/talk"; };
        default = talk;
      });

      overlays.default = final: prev: { talk = mkTalk final; };

      devShells = forAll (pkgs: {
        default = pkgs.mkShell {
          packages = [ pkgs.go pkgs.gopls pkgs.gotools pkgs.espeak-ng pkgs.libnotify ];
        };
      });

      formatter = forAll (pkgs: pkgs.nixfmt-rfc-style);
    };
}