diff --git a/app/templates/admin/base.html b/app/templates/admin/base.html
index 1e7df38e..1f739768 100644
--- a/app/templates/admin/base.html
+++ b/app/templates/admin/base.html
@@ -75,6 +75,9 @@
     <!-- Quill CSS with CDN fallback (loaded on demand via block) -->
     {% block quill_css %}{% endblock %}
 
+    <!-- Dev debug toolbar (dev only — auto-hides in production, must load early for interceptors) -->
+    <script src="{{ url_for('static', path='shared/js/dev-toolbar.js') }}"></script>
+
     {% block extra_head %}{% endblock %}
 </head>
 <body x-cloak>
diff --git a/app/templates/merchant/base.html b/app/templates/merchant/base.html
index 88734252..2559a09b 100644
--- a/app/templates/merchant/base.html
+++ b/app/templates/merchant/base.html
@@ -25,6 +25,9 @@
         [x-cloak] { display: none !important; }
     </style>
 
+    <!-- Dev debug toolbar (dev only — auto-hides in production, must load early for interceptors) -->
+    <script src="{{ url_for('static', path='shared/js/dev-toolbar.js') }}"></script>
+
     {% block extra_head %}{% endblock %}
 </head>
 <body x-cloak>
diff --git a/app/templates/storefront/base.html b/app/templates/storefront/base.html
index 2a075e31..b6508a59 100644
--- a/app/templates/storefront/base.html
+++ b/app/templates/storefront/base.html
@@ -50,6 +50,9 @@
     {# Base Shop Styles #}
     <link rel="stylesheet" href="{{ url_for('static', path='storefront/css/storefront.css') }}">
 
+    {# Dev debug toolbar (dev only — auto-hides in production, must load early for interceptors) #}
+    <script src="{{ url_for('static', path='shared/js/dev-toolbar.js') }}"></script>
+
     {% block extra_head %}{% endblock %}
 </head>
 
