try 2 , nix run copies the script to a dir... without checking if it's there, i should add alternate store location to nix-ran version

flake.lock

@@ -1,59 +1,25 @@
 {
   "nodes": {
-    "flake-utils": {
-      "inputs": {
-        "systems": "systems"
-      },
-      "locked": {
-        "lastModified": 1731533236,
-        "narHash": "sha256-l0KFg5HjrsfsO/JpG+r7fRrqm12kzFHyUHqHCVpMMbI=",
-        "owner": "numtide",
-        "repo": "flake-utils",
-        "rev": "11707dc2f618dd54ca8739b309ec4fc024de578b",
-        "type": "github"
-      },
-      "original": {
-        "owner": "numtide",
-        "repo": "flake-utils",
-        "type": "github"
-      }
-    },
     "nixpkgs": {
       "locked": {
-        "lastModified": 1751274312,
-        "narHash": "sha256-/bVBlRpECLVzjV19t5KMdMFWSwKLtb5RyXdjz3LJT+g=",
-        "owner": "NixOS",
+        "lastModified": 1765311797,
+        "narHash": "sha256-mSD5Ob7a+T2RNjvPvOA1dkJHGVrNVl8ZOrAwBjKBDQo=",
+        "owner": "nixos",
         "repo": "nixpkgs",
-        "rev": "50ab793786d9de88ee30ec4e4c24fb4236fc2674",
+        "rev": "09eb77e94fa25202af8f3e81ddc7353d9970ac1b",
         "type": "github"
       },
       "original": {
-        "owner": "NixOS",
-        "ref": "nixos-24.11",
+        "owner": "nixos",
+        "ref": "nixos-25.11",
         "repo": "nixpkgs",
         "type": "github"
       }
     },
     "root": {
       "inputs": {
-        "flake-utils": "flake-utils",
         "nixpkgs": "nixpkgs"
       }
-    },
-    "systems": {
-      "locked": {
-        "lastModified": 1681028828,
-        "narHash": "sha256-Vy1rq5AaRuLzOxct8nz4T6wlgyUR7zLU309k9mBC768=",
-        "owner": "nix-systems",
-        "repo": "default",
-        "rev": "da67096a3b9bf56a91d16901293e51ba5b49a27e",
-        "type": "github"
-      },
-      "original": {
-        "owner": "nix-systems",
-        "repo": "default",
-        "type": "github"
-      }
     }
   },
   "root": "root",

flake.nix

@@ -1,40 +1,70 @@
 {
-  description = "run py2fa-gtk";
+  description = "Install main.py to data directory with dependencies";
 
-  inputs = {
-    nixpkgs.url = "github:NixOS/nixpkgs/nixos-24.11";
-    flake-utils.url = "github:numtide/flake-utils";
-  };
+  inputs.nixpkgs.url = "github:nixos/nixpkgs/nixos-25.11";
 
-  outputs = { self, nixpkgs, flake-utils }:
-    flake-utils.lib.eachDefaultSystem (system:
-      let
-        pkgs = import nixpkgs { inherit system; };
-        python = pkgs.python312 or pkgs.python3;
-      in {
-        devShells.default = pkgs.mkShell {
-          name = "py2fa-gtk-shell";
+  outputs = { self, nixpkgs }:
+    let
+      system = "x86_64-linux";
+      pkgs = nixpkgs.legacyPackages.${system};
+      packageName = "py2fa-gtk";
+      scriptSource = ./src/main.py;
 
-          nativeBuildInputs = [
-            pkgs.gobject-introspection
-          ];
+      # 1. Define Python environment
+      python = pkgs.python312.withPackages (ps: with ps; [
+        cryptography 
+        opencv-python 
+        pygobject3 
+        pyotp 
+        pyzbar
+      ]);
 
-          buildInputs = [
-            (python.withPackages (ps: with ps; [
-              cryptography
-              opencv4
-              pygobject3
-              pyotp
-              pyzbar
-            ]))
-            pkgs.gtk3
-            pkgs.zbar
-          ];
+      # 2. Define libraries for ZBar (shared object)
+      zbarLibs = [ pkgs.zbar ];
 
-          shellHook = ''
-            echo "Environment ready. Run the app with:"
-            echo "  python main.py"
-          '';
-        };
-      });
+    in
+    {
+      packages.${system}.default = pkgs.stdenv.mkDerivation {
+        name = packageName;
+
+        nativeBuildInputs = [ pkgs.wrapGAppsHook3 ];
+
+        buildInputs = with pkgs; [
+          gtk3
+          pango
+          gdk-pixbuf
+          atk
+          cairo
+          gobject-introspection
+          # Python env included here so the wrapper knows about it
+          python
+        ] ++ zbarLibs;
+
+        dontUnpack = true;
+
+        installPhase = ''
+          mkdir -p $out/bin
+
+          cat > $out/bin/${packageName} <<EOF
+#!/bin/sh
+export LD_LIBRARY_PATH="${pkgs.lib.makeLibraryPath zbarLibs}:\$LD_LIBRARY_PATH"
+
+TARGET_DIR="\$HOME/.local/share/${packageName}"
+TARGET_FILE="\$TARGET_DIR/main.py"
+
+mkdir -p "\$TARGET_DIR"
+
+if [ ! -f "\$TARGET_FILE" ]; then
+  echo "Installing main.py to \$TARGET_FILE..."
+  cp "${scriptSource}" "\$TARGET_FILE"
+  chmod +w "\$TARGET_FILE"
+fi
+
+exec ${python}/bin/python3 "\$TARGET_FILE" "\$@"
+EOF
+          
+          chmod +x $out/bin/${packageName}
+        '';
+      };
+    };
 }