{
  description = "arr-tui: a terminal UI (and webOS TV app) for Radarr, Sonarr and SABnzbd";

  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});
    in
    {
      # nix develop: everything make test, the release script, the README
      # screenshots (dev/screenshots) and the webOS app (webos/) need.
      # Containers for dev/up.sh (docker or podman) come from the system.
      devShells = forAll (pkgs: {
        default = pkgs.mkShell {
          packages = with pkgs; [
            # arr-tui
            go
            gopls
            gnumake
            shellcheck
            git
            # scripts/release.sh, dev/up.sh
            curl
            jq
            # dev/screenshots (fake services), webos (app, tests, ares CLI)
            python3
            nodejs_24
            # README pictures: oxipng compresses them
            oxipng
            imagemagick
          ] ++ lib.optionals stdenv.hostPlatform.isLinux [
            # dev/screenshots/take.sh: Ghostty on a virtual X display
            ghostty
            xvfb-run
            xorg-server
            xdotool
            fontconfig
            dejavu_fonts
            # webos/dev/drive.mjs
            chromium
          ];

          # posters.sh asks fontconfig for the DejaVu fonts: the system's
          # fonts plus DejaVu.
          FONTCONFIG_FILE = pkgs.lib.optionalString pkgs.stdenv.hostPlatform.isLinux (pkgs.writeText "fonts.conf" ''
            <?xml version="1.0"?>
            <!DOCTYPE fontconfig SYSTEM "urn:fontconfig:fonts.dtd">
            <fontconfig>
              <include ignore_missing="yes">/etc/fonts/fonts.conf</include>
              <dir>${pkgs.dejavu_fonts}/share/fonts</dir>
            </fontconfig>
          '');

          shellHook = pkgs.lib.optionalString pkgs.stdenv.hostPlatform.isLinux ''
            export CHROMIUM=${pkgs.chromium}/bin/chromium
          '';
        };
      });
    };
}