Accepting Payments with Stripe Checkout

Every SaaS product, marketplace, and digital store eventually needs to take money. Stripe is the dominant infrastructure layer for that job, and Checkout is its highest-leverage entry point. Instead of building your own payment form, handling card tokenization, and worrying about PCI compliance, you hand a user off to a Stripe-hosted page and receive a webhook when the money moves.

API Keys and Environment Setup

Stripe gives every account two key pairs: publishable and secret, each in test and live variants. The publishable key is safe to expose in client-side JavaScript. The secret key must never leave your server.

Retrieve both from the Stripe Dashboard → Developers → API Keys. Store the secret key in an environment variable — never hard-code it in source.

STRIPE_SECRET_KEY=sk_test_51...
STRIPE_PUBLISHABLE_KEY=pk_test_51...
STRIPE_WEBHOOK_SECRET=whsec_...

Install the SDK:

npm install stripe   # Node.js
pip install stripe   # Python

Creating a Checkout Session

A Checkout Session is a server-side object that represents a pending payment. You create it with the items, amounts, currency, and redirect URLs, then redirect the user to session.url. Stripe handles everything from there — card entry, 3D Secure, error messages.

const stripe = require('stripe')(process.env.STRIPE_SECRET_KEY);

const session = await stripe.checkout.sessions.create({
  payment_method_types: ['card'],
  line_items: [{
    price_data: {
      currency: 'usd',
      product_data: { name: 'Pro Plan' },
      unit_amount: 4900,        // cents
    },
    quantity: 1,
  }],
  mode: 'payment',
  success_url: `\${YOUR_DOMAIN}/success?session_id={CHECKOUT_SESSION_ID}`,
  cancel_url:  `\${YOUR_DOMAIN}/cancel`,
});

res.redirect(303, session.url);

Success, Cancel, and the Session Object

After payment, Stripe redirects back to your success_url with a session_id query parameter. Retrieve the session on your success page to confirm the payment status before granting access.

const sessionId = req.query.session_id;
const session = await stripe.checkout.sessions.retrieve(sessionId);

if (session.payment_status === 'paid') {
  // provision access, send receipt email, update DB
}