stripe-payments

Stripe Payments

Add Stripe payments to a web app. Covers the common patterns — one-time payments, subscriptions, webhooks, customer portal — with working code. No MCP server needed.

Which Stripe API Do I Need?

You want to...	Use	Complexity
Accept a one-time payment	Checkout Sessions	Low — Stripe hosts the payment page
Embed a payment form in your UI	Payment Element + Payment Intents	Medium — you build the form, Stripe handles the card
Recurring billing / subscriptions	Checkout Sessions (subscription mode)	Low-Medium
Save a card for later	Setup Intents	Low
Marketplace / platform payments	Stripe Connect	High
Let customers manage billing	Customer Portal	Low — Stripe hosts it

Default recommendation: Start with Checkout Sessions. It's the fastest path to accepting money. You can always add embedded forms later.

Setup

Install

npm install stripe @stripe/stripe-js

API Keys

# Get keys from: https://dashboard.stripe.com/apikeys
# Test keys start with sk_test_ and pk_test_
# Live keys start with sk_live_ and pk_live_

# For Cloudflare Workers — store as secrets:
npx wrangler secret put STRIPE_SECRET_KEY
npx wrangler secret put STRIPE_WEBHOOK_SECRET

# For local dev — .dev.vars:
STRIPE_SECRET_KEY=sk_test_...
STRIPE_WEBHOOK_SECRET=whsec_...
STRIPE_PUBLISHABLE_KEY=pk_test_...

Server-Side Client

import Stripe from 'stripe';

// Cloudflare Workers
const stripe = new Stripe(c.env.STRIPE_SECRET_KEY);

// Node.js
const stripe = new Stripe(process.env.STRIPE_SECRET_KEY!);

One-Time Payment (Checkout Sessions)

The fastest way to accept payment. Stripe hosts the entire checkout page.

Create a Checkout Session (Server)

app.post('/api/checkout', async (c) => {
  const { priceId, successUrl, cancelUrl } = await c.req.json();

  const session = await stripe.checkout.sessions.create({
    mode: 'payment',
    line_items: [{ price: priceId, quantity: 1 }],
    success_url: successUrl || `${new URL(c.req.url).origin}/success?session_id={CHECKOUT_SESSION_ID}`,
    cancel_url: cancelUrl || `${new URL(c.req.url).origin}/pricing`,
  });

  return c.json({ url: session.url });
});

Redirect to Checkout (Client)

async function handleCheckout(priceId: string) {
  const res = await fetch('/api/checkout', {
    method: 'POST',
    headers: { 'Content-Type': 'application/json' },
    body: JSON.stringify({ priceId }),
  });
  const { url } = await res.json();
  window.location.href = url;
}

Create Products and Prices

# Via Stripe CLI (recommended for setup)
stripe products create --name="Pro Plan" --description="Full access"
stripe prices create --product=prod_XXX --unit-amount=2900 --currency=aud --recurring[interval]=month

# Or via Dashboard: https://dashboard.stripe.com/products

Hardcode price IDs in your code (they don't change):

const PRICES = {
  pro_monthly: 'price_1234567890',
  pro_yearly: 'price_0987654321',
} as const;

Subscriptions

Same as one-time but with mode: 'subscription':

const session = await stripe.checkout.sessions.create({
  mode: 'subscription',
  line_items: [{ price: PRICES.pro_monthly, quantity: 1 }],
  success_url: `${origin}/dashboard?session_id={CHECKOUT_SESSION_ID}`,
  cancel_url: `${origin}/pricing`,
  // Link to existing customer if known:
  customer: customerId, // or customer_email: 'user@example.com'
});

Check Subscription Status

async function hasActiveSubscription(customerId: string): Promise<boolean> {
  const subs = await stripe.subscriptions.list({
    customer: customerId,
    status: 'active',
    limit: 1,
  });
  return subs.data.length > 0;
}

Webhooks

Stripe sends events to your server when things happen (payment succeeded, subscription cancelled, etc.). You must verify the webhook signature.

Webhook Handler (Cloudflare Workers / Hono)

app.post('/api/webhooks/stripe', async (c) => {
  const body = await c.req.text();
  const sig = c.req.header('stripe-signature')!;

  let event: Stripe.Event;
  try {
    // Use constructEventAsync for Workers (no Node crypto)
    event = await stripe.webhooks.constructEventAsync(
      body,
      sig,
      c.env.STRIPE_WEBHOOK_SECRET
    );
  } catch (err) {
    console.error('Webhook signature verification failed:', err);
    return c.json({ error: 'Invalid signature' }, 400);
  }

  switch (event.type) {
    case 'checkout.session.completed': {
      const session = event.data.object as Stripe.Checkout.Session;
      // Fulfill the order — update database, send email, grant access
      await handleCheckoutComplete(session);
      break;
    }
    case 'customer.subscription.updated': {
      const sub = event.data.object as Stripe.Subscription;
      await handleSubscriptionChange(sub);
      break;
    }
    case 'customer.subscription.deleted': {
      const sub = event.data.object as Stripe.Subscription;
      await handleSubscriptionCancelled(sub);
      break;
    }
    case 'invoice.payment_failed': {
      const invoice = event.data.object as Stripe.Invoice;
      await handlePaymentFailed(invoice);
      break;
    }
  }

  return c.json({ received: true });
});

Register Webhook

# Local testing with Stripe CLI:
stripe listen --forward-to http://localhost:8787/api/webhooks/stripe

# Production — register via Dashboard:
# https://dashboard.stripe.com/webhooks
# URL: https://yourapp.com/api/webhooks/stripe
# Events: checkout.session.completed, customer.subscription.updated,
#          customer.subscription.deleted, invoice.payment_failed

Cloudflare Workers Gotcha

constructEvent (synchronous) uses Node.js crypto which doesn't exist in Workers. Use constructEventAsync instead — it uses the Web Crypto API.

Customer Portal

Let customers manage their own subscriptions (upgrade, downgrade, cancel, update payment method):

app.post('/api/billing/portal', async (c) => {
  const { customerId } = await c.req.json();

  const session = await stripe.billingPortal.sessions.create({
    customer: customerId,
    return_url: `${new URL(c.req.url).origin}/dashboard`,
  });

  return c.json({ url: session.url });
});

Configure the portal in Dashboard: https://dashboard.stripe.com/settings/billing/portal

Pricing Page Pattern

Generate a pricing page that reads from Stripe products:

// Server: fetch products and prices
app.get('/api/pricing', async (c) => {
  const prices = await stripe.prices.list({
    active: true,
    expand: ['data.product'],
    type: 'recurring',
  });

  return c.json(prices.data.map(price => ({
    id: price.id,
    name: (price.product as Stripe.Product).name,
    description: (price.product as Stripe.Product).description,
    amount: price.unit_amount,
    currency: price.currency,
    interval: price.recurring?.interval,
  })));
});

Or hardcode if you only have 2-3 plans — simpler and no API call on every page load.

Stripe CLI (Local Development)

# Install
brew install stripe/stripe-cli/stripe

# Login
stripe login

# Listen for webhooks locally
stripe listen --forward-to http://localhost:8787/api/webhooks/stripe

# Trigger test events
stripe trigger checkout.session.completed
stripe trigger customer.subscription.created
stripe trigger invoice.payment_failed

Common Patterns

Link Stripe Customer to Your User

// On first checkout, create or find customer:
const session = await stripe.checkout.sessions.create({
  customer_email: user.email,  // Creates new customer if none exists
  // OR
  customer: user.stripeCustomerId,  // Use existing
  metadata: { userId: user.id },  // Link back to your user
  // ...
});

// In webhook, save the customer ID:
case 'checkout.session.completed': {
  const session = event.data.object;
  await db.update(users)
    .set({ stripeCustomerId: session.customer as string })
    .where(eq(users.id, session.metadata.userId));
}

Free Trial

const session = await stripe.checkout.sessions.create({
  mode: 'subscription',
  line_items: [{ price: PRICES.pro_monthly, quantity: 1 }],
  subscription_data: {
    trial_period_days: 14,
  },
  // ...
});

Australian Dollars

// Set currency when creating prices
const price = await stripe.prices.create({
  product: 'prod_XXX',
  unit_amount: 2900,  // $29.00 in cents
  currency: 'aud',
  recurring: { interval: 'month' },
});

Gotchas

Gotcha	Fix
constructEvent fails on Workers	Use constructEventAsync (Web Crypto API)
Webhook fires but handler not called	Check the endpoint URL matches exactly (trailing slash matters)
Test mode payments not appearing	Make sure you're using sk_test_ key, not sk_live_
Price amounts are in cents	2900 = $29.00. Always divide by 100 for display
Customer email doesn't match user	Use customer (existing ID) not customer_email for returning users
Subscription status stale	Don't cache — check via API or trust webhook events
Webhook retries	Stripe retries failed webhooks for up to 3 days. Return 200 quickly.
CORS on checkout redirect	Checkout URL is on stripe.com — use window.location.href, not fetch