Add strict Stripe checkout guard via env flag

backend/services/subscription/stripe_service.py

@@ -16,6 +16,10 @@ REQUIRED_STRIPE_PLAN_KEYS = {
 }
 
 
+def _is_truthy_env(var_name: str) -> bool:
+    return os.getenv(var_name, "").strip().lower() in {"1", "true", "yes", "on"}
+
+
 def _detect_stripe_mode() -> str:
     configured_mode = os.getenv("STRIPE_MODE", "").strip().lower()
     if configured_mode in {"test", "live"}:
@@ -98,7 +102,16 @@ class StripeService:
         self.db = db
         self.api_key = os.getenv("STRIPE_SECRET_KEY")
         self.webhook_secret = os.getenv("STRIPE_WEBHOOK_SECRET")
+        self.require_stripe_checkout = _is_truthy_env("REQUIRE_STRIPE_CHECKOUT")
         if not self.api_key:
+            if self.require_stripe_checkout:
+                raise HTTPException(
+                    status_code=500,
+                    detail=(
+                        "REQUIRE_STRIPE_CHECKOUT=true but STRIPE_SECRET_KEY is missing. "
+                        "Configure STRIPE_SECRET_KEY to enable Stripe checkout."
+                    ),
+                )
             logger.warning("STRIPE_SECRET_KEY is not set. Stripe integration will not work.")
         else:
             stripe.api_key = self.api_key

frontend/src/components/Pricing/PricingPage.tsx

@@ -52,6 +52,10 @@ export interface SubscriptionPlan {
 }
 
 const PricingPage: React.FC = () => {
+  const requireStripeCheckout = ['1', 'true', 'yes', 'on'].includes(
+    (process.env.REACT_APP_REQUIRE_STRIPE_CHECKOUT || '').toLowerCase()
+  );
+  const stripePublishableKey = process.env.REACT_APP_STRIPE_PUBLISHABLE_KEY;
   const navigate = useNavigate();
   const [plans, setPlans] = useState<SubscriptionPlan[]>([]);
   const [loading, setLoading] = useState(true);
@@ -173,7 +177,7 @@ const PricingPage: React.FC = () => {
       const userId = localStorage.getItem('user_id') || 'anonymous';
 
       // Check if Stripe is configured
-      if (process.env.REACT_APP_STRIPE_PUBLISHABLE_KEY) {
+      if (stripePublishableKey) {
         console.log('[PricingPage] Initiating Stripe Checkout');
 
         const response = await apiClient.post('/api/subscription/create-checkout-session', {
@@ -187,6 +191,14 @@ const PricingPage: React.FC = () => {
           window.location.href = response.data.url;
           return;
         }
+
+        if (requireStripeCheckout) {
+          throw new Error('Stripe checkout is required but checkout URL was not returned.');
+        }
+      } else if (requireStripeCheckout) {
+        throw new Error(
+          'Stripe checkout is required but REACT_APP_STRIPE_PUBLISHABLE_KEY is not configured.'
+        );
       }
 
       console.log('[PricingPage] Making legacy subscription API call:', {
@@ -271,7 +283,8 @@ const PricingPage: React.FC = () => {
       }, 3000);
     } catch (err) {
       console.error('Error subscribing:', err);
-      setError('Failed to process subscription');
+      const errorMessage = err instanceof Error ? err.message : 'Failed to process subscription';
+      setError(errorMessage);
       setSuccessSnackbar({ open: false, message: '', countdown: 0 });
     } finally {
       setSubscribing(false);