---

name: stripe description: "Help with Stripe payment integration in Next.js projects. Use when implementing checkout flows, subscriptions, webhooks, customer portal, or debugging payment issues. Covers Stripe SDK usage, webhook verification, and subscription management." allowed-tools: Read, Glob, Grep, Write, Edit, Bash, WebSearch

Stripe Integration Helper

Assist with Stripe payment gateway integration for SaaS applications.

Quick Reference

Installation

Copybun add stripe @stripe/stripe-js

Environment Variables

Copy# Server-side (secret)
STRIPE_SECRET_KEY="sk_live_..."
STRIPE_WEBHOOK_SECRET="whsec_..."

# Client-side (publishable)
NEXT_PUBLIC_STRIPE_PUBLISHABLE_KEY="pk_live_..."

# App URL for callbacks
NEXT_PUBLIC_APP_URL="https://your-app.com"

SDK Initialization

Server-side:

Copy// lib/stripe.ts
import Stripe from "stripe";

export const stripe = new Stripe(process.env.STRIPE_SECRET_KEY!, {
  apiVersion: "2025-01-27.acacia",
  typescript: true,
});

Client-side:

Copy// lib/stripe-client.ts
import { loadStripe } from "@stripe/stripe-js";

export const stripePromise = loadStripe(
  process.env.NEXT_PUBLIC_STRIPE_PUBLISHABLE_KEY!
);

Common Tasks

1. Create Checkout Session

Copy// app/api/checkout/route.ts
import { NextRequest, NextResponse } from "next/server";
import { auth } from "@clerk/nextjs/server";
import { stripe } from "@/lib/stripe";

export async function POST(request: NextRequest) {
  const { userId } = await auth();
  if (!userId) {
    return NextResponse.json({ error: "Unauthorized" }, { status: 401 });
  }

  const { priceId } = await request.json();

  const session = await stripe.checkout.sessions.create({
    mode: "subscription",
    payment_method_types: ["card"],
    line_items: [{ price: priceId, quantity: 1 }],
    success_url: `${process.env.NEXT_PUBLIC_APP_URL}/billing/success?session_id={CHECKOUT_SESSION_ID}`,
    cancel_url: `${process.env.NEXT_PUBLIC_APP_URL}/pricing`,
    metadata: { userId },
    customer_email: user.email, // Optional: pre-fill email
  });

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

2. Create Customer Portal Session

Copy// app/api/billing/portal/route.ts
export async function POST(request: NextRequest) {
  const { userId } = await auth();
  if (!userId) {
    return NextResponse.json({ error: "Unauthorized" }, { status: 401 });
  }

  // Get Stripe customer ID from your database
  const user = await db.query.users.findFirst({
    where: eq(users.id, userId),
  });

  if (!user?.stripeCustomerId) {
    return NextResponse.json({ error: "No subscription" }, { status: 400 });
  }

  const session = await stripe.billingPortal.sessions.create({
    customer: user.stripeCustomerId,
    return_url: `${process.env.NEXT_PUBLIC_APP_URL}/dashboard`,
  });

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

3. Webhook Handler

Copy// app/api/webhooks/stripe/route.ts
import { NextRequest, NextResponse } from "next/server";
import { stripe } from "@/lib/stripe";
import Stripe from "stripe";

export async function POST(request: NextRequest) {
  const body = await request.text();
  const signature = request.headers.get("stripe-signature")!;

  let event: Stripe.Event;

  try {
    event = stripe.webhooks.constructEvent(
      body,
      signature,
      process.env.STRIPE_WEBHOOK_SECRET!
    );
  } catch (err) {
    console.error("Webhook signature verification failed");
    return NextResponse.json({ error: "Invalid signature" }, { status: 400 });
  }

  switch (event.type) {
    case "checkout.session.completed": {
      const session = event.data.object as Stripe.Checkout.Session;
      await handleCheckoutComplete(session);
      break;
    }
    case "customer.subscription.updated": {
      const subscription = event.data.object as Stripe.Subscription;
      await handleSubscriptionUpdate(subscription);
      break;
    }
    case "customer.subscription.deleted": {
      const subscription = event.data.object as Stripe.Subscription;
      await handleSubscriptionCancelled(subscription);
      break;
    }
    case "invoice.payment_failed": {
      const invoice = event.data.object as Stripe.Invoice;
      await handlePaymentFailed(invoice);
      break;
    }
  }

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

Webhook Events

Subscription Status Values

Database Schema

Users Table (add Stripe fields)

CopystripeCustomerId    TEXT UNIQUE
stripeSubscriptionId TEXT
stripePriceId       TEXT
stripeCurrentPeriodEnd TIMESTAMP

Subscription Sync Pattern

Copyasync function syncSubscription(
  userId: string,
  subscription: Stripe.Subscription
) {
  await db
    .update(users)
    .set({
      stripeSubscriptionId: subscription.id,
      stripePriceId: subscription.items.data[0].price.id,
      stripeCurrentPeriodEnd: new Date(subscription.current_period_end * 1000),
    })
    .where(eq(users.id, userId));
}

Feature Gating

Copyasync function checkFeatureAccess(userId: string): Promise<boolean> {
  const user = await db.query.users.findFirst({
    where: eq(users.id, userId),
  });

  if (!user?.stripeSubscriptionId) return false;

  // Check if subscription is still valid
  const now = new Date();
  return user.stripeCurrentPeriodEnd > now;
}

Testing

Test Card Numbers

Stripe CLI for Local Webhooks

Copy# Install Stripe CLI
brew install stripe/stripe-cli/stripe

# Login
stripe login

# Forward webhooks to local
stripe listen --forward-to localhost:3000/api/webhooks/stripe

# Trigger test events
stripe trigger checkout.session.completed

Pricing Page Pattern

Copy// Get prices from Stripe
const prices = await stripe.prices.list({
  active: true,
  expand: ["data.product"],
});

// Display in component
{prices.data.map((price) => (
  <PriceCard
    key={price.id}
    name={(price.product as Stripe.Product).name}
    price={price.unit_amount! / 100}
    interval={price.recurring?.interval}
    priceId={price.id}
  />
))}

Security Best Practices

1. Never expose secret key - Use STRIPE_SECRET_KEY only server-side
2. Verify webhook signatures - Always use stripe.webhooks.constructEvent
3. Idempotency - Store event IDs to prevent duplicate processing
4. Raw body for webhooks - Don't parse JSON before verification
5. Use metadata - Store userId in checkout session metadata

Common Issues

Useful Commands

Copy# List products
stripe products list

# List prices
stripe prices list

# Get subscription
stripe subscriptions retrieve sub_xxx

# Cancel subscription
stripe subscriptions cancel sub_xxx