Think Like a King

"The world is not short of problems. It is short of governed minds."

A full-stack e-commerce storefront for the book Think Like a King by Michael King — built with Next.js 16, Stripe, Prisma, Resend, and Lulu print-on-demand. Customers can purchase a token-secured digital download or a premium hardcover edition shipped globally.

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Table of Contents

• Overview
• Tech Stack
• Project Structure
• How It Works
  • Checkout Flow
  • Order Fulfillment
  • Download System
  • Webhook Architecture
• Environment Variables
• Database
• Getting Started
• API Reference
• Email Templates
• Deployment Notes

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Overview

The site is a single-page storefront with a modal-based checkout. There are two purchasable editions:

Edition	Price	Fulfillment
E-Book	$9.99 (configurable)	Token-secured download link emailed instantly
Hardcover	$24.99 (configurable)	Print-on-demand via Lulu, shipped globally

Payment is handled entirely by Stripe Checkout. After a successful payment, the success page polls the order status API which verifies the session directly with Stripe as a fallback — meaning the flow works in local development without a live webhook tunnel.

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Tech Stack

Layer	Technology
Framework	Next.js 16 (App Router)
Language	TypeScript 5
Styling	Tailwind CSS v4
Database	PostgreSQL via Prisma 7 + @prisma/adapter-pg
Payments	Stripe (Checkout Sessions, Webhooks)
Email	Resend
Print-on-Demand	Lulu Direct API
Fonts	Germania One, Nunito (Google Fonts)

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Project Structure

src/
├── app/
│   ├── page.tsx                        # Landing page / storefront
│   ├── layout.tsx                      # Root layout, fonts, metadata
│   ├── globals.css                     # Global styles
│   ├── checkout/
│   │   ├── success/page.tsx            # Post-payment success + polling UI
│   │   └── cancel/page.tsx             # Cancelled checkout page
│   └── api/
│       ├── checkout/
│       │   ├── ebook/route.ts          # POST — create Stripe session (e-book)
│       │   └── hardcopy/route.ts       # POST — create Stripe session (hardcopy)
│       ├── order/
│       │   └── status/route.ts         # GET  — poll order status + fallback fulfillment
│       ├── download/
│       │   └── [token]/route.ts        # GET  — validate token, redirect to file
│       └── webhooks/
│           ├── stripe/route.ts         # POST — Stripe checkout.session.completed
│           └── lulu/route.ts           # POST — Lulu LINE_ITEM_SHIPPED
├── components/
│   └── CheckoutModal.tsx               # Two-step checkout modal (edition select → details)
└── lib/
    ├── prisma.ts                       # Prisma client singleton (pg adapter)
    ├── stripe.ts                       # Stripe client
    ├── resend.ts                       # Resend client
    └── emails.ts                       # HTML email templates (ebook, hardcopy, shipped)

prisma/
├── schema.prisma                       # Order, ShippingAddress, enums
└── migrations/                         # Migration history

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How It Works

Checkout Flow

1. Customer clicks Buy the Book anywhere on the landing page.
2. The CheckoutModal opens with a two-step flow:
   • Step 1 — Choose edition (E-Book or Hardcover). A 1.5s transition plays before advancing.
   • Step 2 — Enter name, email, and (for hardcopy) a shipping address.
3. On submit, the modal calls either POST /api/checkout/ebook or POST /api/checkout/hardcopy.
4. The API creates a Stripe Checkout Session using price_data with the amount read from env — no pre-created Stripe products required.
5. The customer is redirected to Stripe's hosted checkout page.
6. On completion, Stripe redirects to /checkout/success?session_id=cs_....

Order Fulfillment

The success page polls GET /api/order/status?session_id=... every 1.5 seconds (up to 20 attempts / 30 seconds).

The status endpoint uses a two-path strategy:

1. Check DB for existing order  →  found → return COMPLETE
                                ↓
                             not found
                                ↓
2. Retrieve session from Stripe → payment_status !== "paid" → return PENDING
                                ↓
                           payment confirmed
                                ↓
3. Create order in DB + send email → return COMPLETE

This means the flow works in two scenarios:

• Production — Stripe webhook fires first, creates the order, DB lookup hits immediately.
• Local dev — Webhook can't reach localhost, so the status endpoint creates the order itself on the first confirmed poll.

Download System

E-book downloads use a UUID token stored on the order record.

• Token is generated at order creation time and expires after 48 hours.
• GET /api/download/[token] validates the token, checks expiry, marks downloadedAt on first access, then issues a 302 redirect to EBOOK_FILE_URL.
• In production, EBOOK_FILE_URL should be a short-lived signed URL from S3 or Vercel Blob — not a permanent public link.

Webhook Architecture

Stripe (POST /api/webhooks/stripe)

• Verifies the stripe-signature header using STRIPE_WEBHOOK_SECRET.
• Only handles checkout.session.completed.
• Routes to handleEbook or handleHardcopy based on metadata.productType.
• Creates the order record and sends the appropriate confirmation email.

Lulu (POST /api/webhooks/lulu)

• Verifies the x-lulu-signature header using HMAC-SHA256 and LULU_WEBHOOK_SECRET.
• Only handles LINE_ITEM_SHIPPED.
• Finds the order by luluOrderId, updates status to SHIPPED, saves tracking info, and sends the shipping notification email.

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Environment Variables

Copy .env and fill in the values. All variables are required unless marked optional.

# ── Database ──────────────────────────────────────────────────────────────────
DATABASE_URL="postgresql://user:password@host:5432/dbname?schema=public"

# ── App ───────────────────────────────────────────────────────────────────────
NEXT_PUBLIC_SITE_URL="http://localhost:3000"

# ── Stripe ────────────────────────────────────────────────────────────────────
# https://dashboard.stripe.com/apikeys
STRIPE_SECRET_KEY="sk_test_..."

# https://dashboard.stripe.com/webhooks — add endpoint: /api/webhooks/stripe
# Events to listen for: checkout.session.completed
STRIPE_WEBHOOK_SECRET="whsec_..."

# ── Pricing (in cents — no Stripe products needed) ────────────────────────────
EBOOK_PRICE_CENTS="999"        # $9.99
HARDCOPY_PRICE_CENTS="2499"    # $24.99

# ── Resend ────────────────────────────────────────────────────────────────────
# https://resend.com/api-keys
RESEND_API_KEY="re_..."
# Must be a verified sender domain in Resend
EMAIL_FROM="orders@yourdomain.com"

# ── E-Book File ───────────────────────────────────────────────────────────────
# Direct URL or signed URL to the PDF/EPUB file
EBOOK_FILE_URL="https://..."

# ── Lulu (Print-on-Demand) ────────────────────────────────────────────────────
# https://developers.lulu.com
LULU_API_KEY="..."
LULU_WEBHOOK_SECRET="..."

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Database

The schema has two models:

Order — one record per completed purchase.

Field	Type	Notes
id	String (cuid)	Primary key
email	String	Customer email
name	String	Customer name
type	ProductType	EBOOK or HARDCOPY
stripeSessionId	String (unique)	Stripe Checkout Session ID
stripePaymentId	String?	Stripe PaymentIntent ID
status	OrderStatus	PENDING → PAID → PROCESSING → SHIPPED
downloadToken	String? (unique)	UUID for e-book download
downloadExpiresAt	DateTime?	48h from order creation
downloadedAt	DateTime?	First download timestamp
luluOrderId	String?	Lulu order reference
trackingNumber	String?	Courier tracking number
trackingUrl	String?	Courier tracking link
shippedAt	DateTime?	Timestamp when shipped

ShippingAddress — one-to-one with Order, hardcopy only.

Field	Type
line1	String
line2	String?
city	String
state	String?
postalCode	String
country	String (ISO 3166-1 alpha-2)

Run migrations:

npx prisma migrate dev

Open Prisma Studio:

npx prisma studio

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Getting Started

Prerequisites: Node.js 20+, PostgreSQL (local or hosted)

# 1. Install dependencies
npm install

# 2. Set up environment variables
# Edit .env with your actual keys (see Environment Variables above)

# 3. Run database migrations
npx prisma migrate dev

# 4. Start the development server
npm run dev

The app will be at http://localhost:3000.

Testing payments locally:

Use Stripe's test card 4242 4242 4242 4242 with any future expiry and any CVC. The order status endpoint will verify the payment directly with Stripe after redirect — no webhook tunnel needed in development.

For webhook testing in dev, use the Stripe CLI:

stripe listen --forward-to localhost:3000/api/webhooks/stripe

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API Reference

POST /api/checkout/ebook

Creates a Stripe Checkout Session for the e-book.

Request body:

{ "name": "John Doe", "email": "john@example.com" }

Response:

{ "url": "https://checkout.stripe.com/..." }

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POST /api/checkout/hardcopy

Creates a Stripe Checkout Session for the hardcover edition.

Request body:

{
  "name": "John Doe",
  "email": "john@example.com",
  "address": {
    "line1": "123 Main St",
    "line2": "Apt 4B",
    "city": "New York",
    "state": "NY",
    "postalCode": "10001",
    "country": "US"
  }
}

Response:

{ "url": "https://checkout.stripe.com/..." }

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GET /api/order/status?session_id=cs_...

Polls order status after checkout. Creates the order as a fallback if the webhook hasn't fired yet.

Response (pending):

{ "status": "PENDING" }

Response (complete):

{
  "status": "COMPLETE",
  "type": "EBOOK",
  "name": "John Doe",
  "email": "john@example.com",
  "downloadToken": "uuid-here-or-null"
}

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GET /api/download/[token]

Validates a download token and redirects to the e-book file.

Status	Meaning
302	Valid token — redirects to file
404	Token not found
410	Token expired
503	EBOOK_FILE_URL not configured

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POST /api/webhooks/stripe

Stripe webhook endpoint. Requires stripe-signature header.

Handles: checkout.session.completed

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POST /api/webhooks/lulu

Lulu webhook endpoint. Requires x-lulu-signature header (HMAC-SHA256).

Handles: LINE_ITEM_SHIPPED

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Email Templates

All emails are plain HTML built in src/lib/emails.ts with no external template engine. They share a dark-themed base layout matching the site's aesthetic — dark background (#1a1714), gold accents (#c9a84c), serif typography.

Template	Trigger	Content
ebookDownloadEmail	E-book order confirmed	Secure download button + fallback link, 48h expiry notice
hardcopyConfirmationEmail	Hardcopy order confirmed	Formatted shipping address, estimated delivery window
hardcopyShippedEmail	Lulu LINE_ITEM_SHIPPED webhook	Tracking number + carrier tracking button

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Deployment Notes

• Set NEXT_PUBLIC_SITE_URL to your production domain (e.g. https://thinklikeaking.com).
• Register /api/webhooks/stripe in the Stripe dashboard under Developers → Webhooks. Subscribe to checkout.session.completed only.
• Register /api/webhooks/lulu in the Lulu developer dashboard. Set LULU_WEBHOOK_SECRET to match.
• EBOOK_FILE_URL should point to a protected file URL. For Vercel Blob or S3, generate a short-lived signed URL at download time rather than storing a permanent public link.
• The Prisma adapter uses the pg connection pool directly — ensure DATABASE_URL points to a connection pooler (e.g. PgBouncer or Neon's pooled endpoint) in production to avoid exhausting connections.
• Prices are controlled entirely via EBOOK_PRICE_CENTS and HARDCOPY_PRICE_CENTS in env. No Stripe dashboard products are required.

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© Think Like a King — Revere & Regent Press