diff --git a/.envrc b/.envrc
new file mode 100644
index 00000000..0154438f
--- /dev/null
+++ b/.envrc
@@ -0,0 +1,14 @@
+# Check if nix is available
+if command -v nix &> /dev/null; then
+    use flake
+    
+    echo "✅ Nix development environment loaded"
+else
+    # Nix is not available - show instructions for non-Nix users
+    echo "⚠️  Nix not detected. Please ensure the following are installed manually:"
+    echo "   - Java JDK 17"
+    echo "   - Python 3 with invoke package"
+    echo "   - Android SDK"
+    echo "   - FVM (Flutter Version Management)"
+    echo "💡 To use Nix: Install from https://nixos.org/download.html"
+fi
diff --git a/.gitignore b/.gitignore
index 8effbf9a..3b84f8e6 100644
--- a/.gitignore
+++ b/.gitignore
@@ -8,6 +8,7 @@
 .buildlog/
 .history
 .svn/
+.direnv
 
 coverage/*
 
diff --git a/NOTE.md b/NOTE.md
new file mode 100644
index 00000000..665c4b3c
--- /dev/null
+++ b/NOTE.md
@@ -0,0 +1,40 @@
+## Codeänderung
+
+- android/app/build.gradle: compileSdkVersion/targetSdkVersion auf 36 angehoben,
+  weil mehrere Plugins SDK 36 voraussetzen.
+
+## Devbuild (out of the box)
+
+```sh
+invoke translate
+flutter build apk --debug
+```
+
+## Releasebuild (benötigt Signatur; interaktiv)
+
+Signatur erstellen; Passwörter merken!:
+
+```sh
+keytool -genkey -v -keystore ~/inventree-release-key.jks \
+  -keyalg RSA -keysize 2048 \
+  -alias inventree
+```
+
+android/key.properties anlegen mit:
+
+```properties
+storePassword=DEIN_STORE_PASSWORD
+keyPassword=DEIN_KEY_PASSWORD
+keyAlias=inventree
+storeFile=/.../inventree-release-key.jks
+```
+
+```sh
+invoke translate
+fvm flutter build apk --release --no-tree-shake-icons
+```
+
+## Pipe
+
+1. nix installieren (für flake nutzung) (optional aber dann reproduzierbar)
+2. flake anwenden
diff --git a/flake.lock b/flake.lock
new file mode 100644
index 00000000..1805babf
--- /dev/null
+++ b/flake.lock
@@ -0,0 +1,61 @@
+{
+  "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": 1767892417,
+        "narHash": "sha256-dhhvQY67aboBk8b0/u0XB6vwHdgbROZT3fJAjyNh5Ww=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "3497aa5c9457a9d88d71fa93a4a8368816fbeeba",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NixOS",
+        "ref": "nixos-unstable",
+        "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",
+  "version": 7
+}
diff --git a/flake.nix b/flake.nix
new file mode 100644
index 00000000..5038e85e
--- /dev/null
+++ b/flake.nix
@@ -0,0 +1,128 @@
+{
+  description = "InvenTree App Development Environment - CTBK";
+
+  inputs = {
+    nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
+    flake-utils.url = "github:numtide/flake-utils";
+  };
+
+  outputs =
+    {
+      self,
+      nixpkgs,
+      flake-utils,
+    }:
+    flake-utils.lib.eachDefaultSystem (
+      system:
+      let
+        pkgs = import nixpkgs {
+          inherit system;
+          config = {
+            allowUnfree = true;
+            android_sdk.accept_license = true;
+          };
+        };
+
+        androidSdk =
+          (pkgs.androidenv.composeAndroidPackages {
+            platformVersions = [
+              "36"
+              "35"
+              "34"
+            ];
+            buildToolsVersions = [
+              "36.0.0"
+              "34.0.0"
+            ];
+            includeEmulator = true;
+            includeNDK = true;
+            ndkVersions = [ "26.1.10909125" ];
+            cmakeVersions = [
+              "3.31.6"
+              "3.22.1"
+            ];
+          }).androidsdk;
+
+        # FVM wrapper for NixOS - maps fvm commands to Nix-managed Flutter
+        fvm-wrapper = pkgs.writeShellScriptBin "fvm" ''
+          case "$1" in
+            use)
+              # 'fvm use' is a no-op on NixOS since Flutter is version-managed by Nix
+              echo "✓ Using Flutter from Nix ($(flutter --version | head -n1))"
+              exit 0
+              ;;
+            flutter)
+              # 'fvm flutter ...' becomes 'flutter ...'
+              shift
+              exec flutter "$@"
+              ;;
+            *)
+              echo "fvm wrapper: command '$1' not implemented (using Nix-managed Flutter)" >&2
+              exit 1
+              ;;
+          esac
+        '';
+      in
+      {
+        devShells.default = pkgs.mkShell {
+          buildInputs =
+            with pkgs;
+            [
+              # Mobile development
+              flutter
+              fvm-wrapper
+              jdk17
+
+              # Build tools
+              android-tools
+              gradle
+
+              # Python & task runner
+              python3
+              python3Packages.invoke
+
+              # System dependencies for Flutter on Linux
+              git
+              curl
+              unzip
+              which
+            ]
+            ++ lib.optionals stdenv.isLinux [
+              gtk3
+              glib
+              pcre
+              libepoxy
+              libxkbcommon
+              dbus
+              at-spi2-core
+              file
+            ];
+
+          shellHook = ''
+            export ANDROID_HOME="${androidSdk}/libexec/android-sdk"
+            export ANDROID_SDK_ROOT="$ANDROID_HOME"
+            export PATH="$ANDROID_HOME/platform-tools:$ANDROID_HOME/tools/bin:$PATH"
+            export JAVA_HOME="${pkgs.jdk17}"
+            export GRADLE_OPTS="-Dorg.gradle.project.android.aapt2FromMavenOverride=$ANDROID_HOME/build-tools/34.0.0/aapt2"
+
+            echo "🚀 InvenTree App Development Environment - CTBK" 
+            echo "📦 Tools: Flutter, FVM, JDK17, Android SDK"
+            echo "📋 Run: invoke android  # Build Android app"
+          '';
+
+          LD_LIBRARY_PATH = pkgs.lib.makeLibraryPath (
+            with pkgs;
+            [
+              gtk3
+              glib
+              pcre
+              libepoxy
+              libxkbcommon
+              dbus
+              at-spi2-core
+            ]
+          );
+        };
+      }
+    );
+}