diff --git a/add_stockholm_device.py b/add_stockholm_device.py
index 82ed155..d612a64 100644
--- a/add_stockholm_device.py
+++ b/add_stockholm_device.py
@@ -54,7 +54,14 @@ def authenticate():
     
     try:
         print(f"🔐 Authenticating as user: {USERNAME}")
-        response = requests.post(f"{API_BASE_URL}/users/login", json=login_data, verify=False)
+        
+        # Add tenant header for localhost requests
+        headers = {"Content-Type": "application/json"}
+        if "localhost" in API_BASE_URL:
+            headers["x-tenant-id"] = "uamils-ab"
+            print(f"🏢 Using tenant: uamils-ab")
+        
+        response = requests.post(f"{API_BASE_URL}/users/login", json=login_data, headers=headers, verify=False)
         
         if response.status_code == 200:
             data = response.json()
@@ -76,15 +83,19 @@ def authenticate():
 
 def get_auth_headers():
     """Get headers with authentication token"""
+    headers = {"Content-Type": "application/json"}
+    
+    # Add tenant header for localhost requests
+    if "localhost" in API_BASE_URL:
+        headers["x-tenant-id"] = "uamils-ab"
+    
     if SKIP_AUTH:
-        return {"Content-Type": "application/json"}
+        return headers
     
     if AUTH_TOKEN:
-        return {
-            "Authorization": f"Bearer {AUTH_TOKEN}",
-            "Content-Type": "application/json"
-        }
-    return {"Content-Type": "application/json"}
+        headers["Authorization"] = f"Bearer {AUTH_TOKEN}"
+    
+    return headers
 
 def get_next_device_id():
     """Get the next available device ID"""
diff --git a/server/models/Device.js b/server/models/Device.js
index 76d82b5..80e44a0 100644
--- a/server/models/Device.js
+++ b/server/models/Device.js
@@ -3,9 +3,9 @@ const { DataTypes } = require('sequelize');
 module.exports = (sequelize) => {
   const Device = sequelize.define('Device', {
     id: {
-      type: DataTypes.INTEGER,
+      type: DataTypes.UUID,
+      defaultValue: sequelize.Sequelize.UUIDV4,
       primaryKey: true,
-      autoIncrement: true,
       allowNull: false,
       comment: 'Unique device identifier'
     },