{
  description = "Image Processor API";

  inputs = {
    nixpkgs.url = "github:NixOS/nixpkgs/nixpkgs-unstable";
    # Ghostty uses 'systems' to be cleaner, we can do similar or stick to a list
  };

  # This mirrors the Ghostty 'nixConfig' to ensure settings stay local to the project
  nixConfig = {
    extra-substituters = ["https://cache.nixos.org"];
    extra-trusted-public-keys = ["cache.nixos.org-1:6NCHdD59X431o0gWypbMrAURkbJ16ZPMQFGspcDShjY="];
  };

  outputs = {
    self,
    nixpkgs,
  }: let
    supportedSystems = ["aarch64-darwin" "x86_64-darwin" "aarch64-linux" "x86_64-linux"];
    # A helper to generate outputs for all systems
    forAllSystems = f: nixpkgs.lib.genAttrs supportedSystems (system: f (import nixpkgs {inherit system;}));
  in {
    # 1. THE PACKAGE (What you 'pull' into other projects)
    packages = forAllSystems (pkgs: {
      default = pkgs.stdenv.mkDerivation {
        pname = "image_processor";
        version = "0.1.0";
        src = ./.;

        nativeBuildInputs = [pkgs.cmake pkgs.pkg-config];
        buildInputs = [pkgs.libjpeg_turbo];

        # Ensure headers are found in the dev environment
        propagatedBuildInputs = [pkgs.libjpeg_turbo];
      };
    });

    # 2. THE DEV SHELL (What 'direnv' uses)
    devShells = forAllSystems (pkgs: {
      default = pkgs.mkShell {
        # Use 'inputsFrom' so the shell always matches the package
        inputsFrom = [self.packages.${pkgs.system}.default];

        # Add extra dev tools you only want when coding, not building
        nativeBuildInputs = with pkgs; [
          gdb
          pkg-config
        ];

        shellHook = ''
          # These exports make sure your C compiler finds the Nix-provided libs
          export CPATH="${pkgs.libjpeg_turbo.dev}/include:$CPATH"
          export LIBRARY_PATH="${pkgs.libjpeg_turbo.out}/lib:$LIBRARY_PATH"
          export PKG_CONFIG_PATH="${pkgs.libjpeg_turbo.dev}/lib/pkgconfig:$PKG_CONFIG_PATH"

          echo "⚙️ Image Processor API Dev Shell Loaded"
        '';
      };
    });
  };
}