feat: Add Stripe checkout integration

- Add checkout API route for creating Stripe sessions
- Add webhook handler for payment events
- Add customer portal API route
- Add CheckoutButton component for book and license purchases
- Add success page for post-payment redirect
- Add contribute page with sponsorship tiers
- Update book page with $49 pre-order button
- Update pricing page with $99 license purchase button
- Update .env.example with Stripe configuration

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <[email protected]>

Author: 2 people

website/.env.example

@@ -29,6 +29,23 @@ NEXT_PUBLIC_PLAUSIBLE_DOMAIN=smartaimemory.com
 # Database (if needed for newsletter/contact storage)
 # DATABASE_URL=postgresql://user:password@localhost:5432/smartaimemory
 
+# Stripe Configuration
+# Get keys from: https://dashboard.stripe.com/apikeys
+STRIPE_SECRET_KEY=sk_live_...
+NEXT_PUBLIC_STRIPE_PUBLISHABLE_KEY=pk_live_...
+# Get from: Developers → Webhooks → [Your endpoint] → Signing secret
+STRIPE_WEBHOOK_SECRET=whsec_...
+
+# Stripe Product Price IDs (get from Dashboard after creating products)
+# These need NEXT_PUBLIC_ prefix to be accessible in client components
+NEXT_PUBLIC_STRIPE_PRICE_BOOK=price_...
+NEXT_PUBLIC_STRIPE_PRICE_LICENSE=price_...
+# Contribution tiers (optional)
+NEXT_PUBLIC_STRIPE_PRICE_CONTRIB_5=price_...
+NEXT_PUBLIC_STRIPE_PRICE_CONTRIB_25=price_...
+NEXT_PUBLIC_STRIPE_PRICE_CONTRIB_100=price_...
+NEXT_PUBLIC_STRIPE_PRICE_CONTRIB_500=price_...
+
 # Deployment
 NODE_ENV=production
 NEXT_PUBLIC_SITE_URL=https://smartaimemory.com

website/app/api/stripe/checkout/route.ts

@@ -0,0 +1,38 @@
+import { NextRequest, NextResponse } from 'next/server';
+import Stripe from 'stripe';
+
+const stripe = new Stripe(process.env.STRIPE_SECRET_KEY!);
+
+export async function POST(req: NextRequest) {
+  try {
+    const { priceId, mode, customerEmail, successUrl, cancelUrl } = await req.json();
+
+    if (!priceId) {
+      return NextResponse.json({ error: 'Price ID is required' }, { status: 400 });
+    }
+
+    const session = await stripe.checkout.sessions.create({
+      mode: mode || 'payment', // 'payment' for one-time, 'subscription' for recurring
+      payment_method_types: ['card'],
+      line_items: [
+        {
+          price: priceId,
+          quantity: 1,
+        },
+      ],
+      success_url: successUrl || `${process.env.NEXT_PUBLIC_SITE_URL}/success?session_id={CHECKOUT_SESSION_ID}`,
+      cancel_url: cancelUrl || `${process.env.NEXT_PUBLIC_SITE_URL}/pricing`,
+      customer_email: customerEmail || undefined,
+      allow_promotion_codes: true,
+      billing_address_collection: 'required',
+      // Collect customer info for fulfillment
+      customer_creation: mode === 'subscription' ? undefined : 'always',
+    });
+
+    return NextResponse.json({ url: session.url, sessionId: session.id });
+  } catch (error) {
+    console.error('Stripe checkout error:', error);
+    const errorMessage = error instanceof Error ? error.message : 'Checkout failed';
+    return NextResponse.json({ error: errorMessage }, { status: 500 });
+  }
+}

website/app/api/stripe/portal/route.ts

@@ -0,0 +1,25 @@
+import { NextRequest, NextResponse } from 'next/server';
+import Stripe from 'stripe';
+
+const stripe = new Stripe(process.env.STRIPE_SECRET_KEY!);
+
+export async function POST(req: NextRequest) {
+  try {
+    const { customerId } = await req.json();
+
+    if (!customerId) {
+      return NextResponse.json({ error: 'Customer ID is required' }, { status: 400 });
+    }
+
+    const session = await stripe.billingPortal.sessions.create({
+      customer: customerId,
+      return_url: `${process.env.NEXT_PUBLIC_SITE_URL}/account`,
+    });
+
+    return NextResponse.json({ url: session.url });
+  } catch (error) {
+    console.error('Stripe portal error:', error);
+    const errorMessage = error instanceof Error ? error.message : 'Portal session failed';
+    return NextResponse.json({ error: errorMessage }, { status: 500 });
+  }
+}

website/app/api/stripe/webhook/route.ts

@@ -0,0 +1,117 @@
+import { NextRequest, NextResponse } from 'next/server';
+import Stripe from 'stripe';
+
+const stripe = new Stripe(process.env.STRIPE_SECRET_KEY!);
+
+// Disable body parsing - we need the raw body for signature verification
+export const runtime = 'nodejs';
+
+export async function POST(req: NextRequest) {
+  const body = await req.text();
+  const sig = req.headers.get('stripe-signature');
+
+  if (!sig) {
+    console.error('Missing stripe-signature header');
+    return NextResponse.json({ error: 'Missing signature' }, { status: 400 });
+  }
+
+  let event: Stripe.Event;
+
+  try {
+    event = stripe.webhooks.constructEvent(
+      body,
+      sig,
+      process.env.STRIPE_WEBHOOK_SECRET!
+    );
+  } catch (err) {
+    const errorMessage = err instanceof Error ? err.message : 'Unknown error';
+    console.error('Webhook signature verification failed:', errorMessage);
+    return NextResponse.json({ error: 'Invalid signature' }, { status: 400 });
+  }
+
+  // Handle the event
+  try {
+    switch (event.type) {
+      case 'checkout.session.completed': {
+        const session = event.data.object as Stripe.Checkout.Session;
+        console.log('Payment successful:', {
+          sessionId: session.id,
+          customerEmail: session.customer_email,
+          amountTotal: session.amount_total,
+          paymentStatus: session.payment_status,
+        });
+
+        // TODO: Implement fulfillment logic
+        // - For book: Send download link email
+        // - For license: Generate and send license key
+        // - For contribution: Send thank you email
+
+        // Example: You could call an internal API or send an email here
+        // await sendConfirmationEmail(session.customer_email, session.id);
+        // await generateLicenseKey(session.customer_email);
+
+        break;
+      }
+
+      case 'customer.subscription.created': {
+        const subscription = event.data.object as Stripe.Subscription;
+        console.log('Subscription created:', {
+          subscriptionId: subscription.id,
+          customerId: subscription.customer,
+          status: subscription.status,
+        });
+        // TODO: Activate license for customer
+        break;
+      }
+
+      case 'customer.subscription.updated': {
+        const subscription = event.data.object as Stripe.Subscription;
+        console.log('Subscription updated:', {
+          subscriptionId: subscription.id,
+          status: subscription.status,
+        });
+        // TODO: Update license status
+        break;
+      }
+
+      case 'customer.subscription.deleted': {
+        const subscription = event.data.object as Stripe.Subscription;
+        console.log('Subscription cancelled:', {
+          subscriptionId: subscription.id,
+          customerId: subscription.customer,
+        });
+        // TODO: Deactivate license
+        break;
+      }
+
+      case 'invoice.paid': {
+        const invoice = event.data.object as Stripe.Invoice;
+        console.log('Invoice paid:', {
+          invoiceId: invoice.id,
+          customerId: invoice.customer,
+          amountPaid: invoice.amount_paid,
+        });
+        // TODO: Extend license period
+        break;
+      }
+
+      case 'invoice.payment_failed': {
+        const invoice = event.data.object as Stripe.Invoice;
+        console.log('Invoice payment failed:', {
+          invoiceId: invoice.id,
+          customerId: invoice.customer,
+        });
+        // TODO: Send payment failed notification
+        break;
+      }
+
+      default:
+        console.log(`Unhandled event type: ${event.type}`);
+    }
+
+    return NextResponse.json({ received: true });
+  } catch (error) {
+    console.error('Error processing webhook:', error);
+    return NextResponse.json({ error: 'Webhook handler failed' }, { status: 500 });
+  }
+}

website/app/book/page.tsx

@@ -1,4 +1,8 @@
 import Link from 'next/link';
+import CheckoutButton from '@/components/CheckoutButton';
+
+// Price ID from Stripe Dashboard - update after creating product
+const BOOK_PRICE_ID = process.env.NEXT_PUBLIC_STRIPE_PRICE_BOOK || 'price_book_placeholder';
 
 export default function BookPage() {
   return (
@@ -82,12 +86,15 @@ export default function BookPage() {
                   </div>
                 </div>
 
-                <button className="btn btn-primary w-full text-lg mb-4" disabled>
-                  Pre-order for December 2025
-                </button>
+                <CheckoutButton
+                  priceId={BOOK_PRICE_ID}
+                  mode="payment"
+                  buttonText="Pre-order Now - $49"
+                  className="btn btn-primary w-full text-lg mb-4"
+                />
 
                 <p className="text-xs text-center text-[var(--muted)]">
-                  Available December 2025. Pre-orders opening soon.
+                  Secure checkout powered by Stripe. Available December 2025.
                 </p>
               </div>
             </div>
@@ -282,9 +289,12 @@ export default function BookPage() {
             <p className="text-xl mb-8 opacity-90">
               The complete guide to building Level 4 Anticipatory AI systems with working commercial plugins.
             </p>
-            <button className="btn bg-white text-[var(--primary)] hover:bg-gray-100 text-lg px-8 py-4" disabled>
-              Pre-orders Opening Soon
-            </button>
+            <CheckoutButton
+              priceId={BOOK_PRICE_ID}
+              mode="payment"
+              buttonText="Pre-order Now - $49"
+              className="btn bg-white text-[var(--primary)] hover:bg-gray-100 text-lg px-8 py-4"
+            />
           </div>
         </div>
       </section>