{
  description = "Global — KDE Connect–compatible companion (Gleam domain + Android UI)";

  inputs = {
    nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
    # Theme crate (own repo). Local override:
    #   nix run .#global --override-input vidya path:$HOME/code/vidya
    # Use the knot HTTPS URL (public, no SSH key). tangled.org AppView HTTPS often 404s.
    vidya = {
      url = "git+https://knot1.tangled.sh/nandi.uk/vidya";
      inputs.nixpkgs.follows = "nixpkgs";
    };
  };

  outputs =
    {
      self,
      nixpkgs,
      vidya,
    }:
    let
      systems = [
        "x86_64-linux"
        "aarch64-linux"
        "x86_64-darwin"
        "aarch64-darwin"
      ];
      forAllSystems = nixpkgs.lib.genAttrs systems;
    in
    {
      packages = forAllSystems (
        system:
        {
          # Re-export the vidya flake package
          vidya = vidya.packages.${system}.default;
          default = vidya.packages.${system}.default;
        }
      );

      apps = forAllSystems (
        system:
        let
          pkgs = nixpkgs.legacyPackages.${system};
          # Device launcher: build APK → adb install → Gleam dist_driver.
          # Bake flake-input path so cargo can path-depend on vidya without vendoring in git.
          global-run =
            (pkgs.writeShellApplication {
              name = "global";
              runtimeInputs = [
                pkgs.gleam
                pkgs.beamPackages.erlang
                pkgs.rebar3
                pkgs.beamPackages.hex
                pkgs.cacert
                pkgs.python3
                pkgs.git
                pkgs.android-tools
                pkgs.gnugrep
                pkgs.gawk
                pkgs.coreutils
                pkgs.procps
                pkgs.bash
                pkgs.cargo
                pkgs.rustc
              ];
              text = ''
                set -euo pipefail
                export SSL_CERT_FILE="${pkgs.cacert}/etc/ssl/certs/ca-bundle.crt"
                export NIX_SSL_CERT_FILE="$SSL_CERT_FILE"
                # Flake-locked vidya sources for cargo path dep (dist-ui → ../.flake/vidya)
                export GLOBAL_VIDYA_SRC="${vidya}"
                ROOT="$(git rev-parse --show-toplevel 2>/dev/null || true)"
                if [ -z "$ROOT" ]; then
                  ROOT="$(pwd)"
                fi
                export GLOBAL_ROOT="$ROOT"
                exec bash "${./scripts/global-run.sh}" "$@"
              '';
            }).overrideAttrs
              (_: {
                preferLocalBuild = true;
                allowSubstitutes = false;
              });
        in
        {
          default = {
            type = "app";
            program = "${global-run}/bin/global";
          };
          global = {
            type = "app";
            program = "${global-run}/bin/global";
          };
        }
      );

      devShells = forAllSystems (
        system:
        let
          pkgs = nixpkgs.legacyPackages.${system};
        in
        {
          default = pkgs.mkShell {
            name = "global";
            packages = [
              pkgs.gleam
              pkgs.beamPackages.erlang
              pkgs.rebar3
              pkgs.beamPackages.hex
              pkgs.git
              pkgs.cacert
              pkgs.android-tools
              pkgs.just
              # Do NOT add pkgs.cargo / pkgs.rustc here: nixpkgs rustc has no
              # x86_64-linux-android std, and shadowing rustup breaks `just waydroid`.
              # Use host rustup (rustc + `rustup target add x86_64-linux-android`).
            ];
            shellHook = ''
              export SSL_CERT_FILE="${pkgs.cacert}/etc/ssl/certs/ca-bundle.crt"
              export NIX_SSL_CERT_FILE="$SSL_CERT_FILE"
              export GLOBAL_VIDYA_SRC="${vidya}"
              # Stage path dep for ad-hoc cargo builds, preferring a local checkout.
              if [ -d dist-ui ]; then
                mkdir -p .flake
                if [ -d "$HOME/code/vidya" ] && [ -f "$HOME/code/vidya/Cargo.toml" ]; then
                  rm -rf .flake/vidya
                  ln -sfn "$HOME/code/vidya" .flake/vidya
                elif [ ! -e .flake/vidya ]; then
                  cp -aL "$GLOBAL_VIDYA_SRC" .flake/vidya
                  chmod -R u+w .flake/vidya
                fi
              fi
              echo "global — device companion (vidya at .flake/vidya)"
              echo "  just waydroid      # APK → Waydroid (needs rustup + android target)"
              echo "  nix run .#global   # APK → install → Gleam"
              echo "  gleam test"
              if ! command -v rustc >/dev/null 2>&1; then
                echo "  warn: no rustc on PATH — install rustup and: rustup target add x86_64-linux-android"
              elif [ ! -d "$(rustc --print sysroot)/lib/rustlib/x86_64-linux-android/lib" ]; then
                echo "  warn: active rustc lacks x86_64-linux-android — run: rustup target add x86_64-linux-android"
                echo "        (and ensure which rustc points at ~/.rustup, not nixpkgs)"
              fi
            '';
          };
        }
      );

      formatter = forAllSystems (system: nixpkgs.legacyPackages.${system}.nixfmt-rfc-style);
    };
}