diff --git a/Machine-Backend/app/__init__.py b/Machine-Backend/app/__init__.py
index fd09701..6eb81b8 100644
--- a/Machine-Backend/app/__init__.py
+++ b/Machine-Backend/app/__init__.py
@@ -65,16 +65,20 @@ def create_app():
         db.create_all()
         print(f"✓ Database initialized ({flask_env})")
         
-        # FIXED: Serial service connection BEFORE return
-        from app.services.services import serial_service
-        try:
-            connected = serial_service.connect_to_machine('/dev/ttyUSB0', 9600)
-            if connected:
-                print("✓ Vending machine connected successfully")
-            else:
-                print("✗ Failed to connect to vending machine")
-        except Exception as e:
-            print(f"⚠ Serial connection error: {e}")
+        # OPTIONAL: Serial service connection (non-blocking)
+        # Only attempt connection if ENABLE_SERIAL is set to true
+        if os.getenv('ENABLE_SERIAL', 'false').lower() == 'true':
+            from app.services.services import serial_service
+            try:
+                connected = serial_service.connect_to_machine('/dev/ttyUSB0', 9600)
+                if connected:
+                    print("✓ Vending machine connected successfully")
+                else:
+                    print("⚠ Vending machine not connected (device may not be available)")
+            except Exception as e:
+                print(f"⚠ Serial connection skipped: {e}")
+        else:
+            print("ℹ Serial connection disabled (set ENABLE_SERIAL=true to enable)")
 
     # Register blueprints
     from app.routes.routes import bp
diff --git a/Machine-Backend/requirements.txt b/Machine-Backend/requirements.txt
index 43101f1..e6b766f 100644
--- a/Machine-Backend/requirements.txt
+++ b/Machine-Backend/requirements.txt
@@ -5,4 +5,5 @@ python-dotenv
 pymysql
 gunicorn
 cryptography
-pyserial
\ No newline at end of file
+pyserial
+PyJWT
\ No newline at end of file