Stripe Webhook Event Handler | Signature Verification with request body as string | Next.js 13.4 appDir

route.ts

// file path: app/api/stripe/webhook/route.ts
import { prisma } from "@/lib/prisma";
import { NextResponse } from "next/server";

import Stripe from "stripe";

export async function POST(request: Request) {
  const body = await request.text();

  const sig = request.headers.get("Stripe-Signature");
  if (!sig) {
    console.log("No signature");
    return NextResponse.json({ error: "No signature" });
  }

  const stripe = new Stripe(process.env.STRIPE_API_KEY!, {
    apiVersion: "2022-11-15",
    typescript: true,
  });

  let event: Stripe.Event;

  try {
    event = stripe.webhooks.constructEvent(
      body,
      sig,
      process.env.STRIPE_WEBHOOK_SECRET!
    );
  } catch (err: any) {
    console.log(`Webhook signature verification failed.`, err.message);
    return NextResponse.json({ error: err });
  }

  console.log("received ", event.type);

  // Handle the event
  switch (event.type) {
    case "payment_intent.succeeded":
      const paymentIntent = event.data.object as Stripe.Checkout.Session;
      const userId = Number(paymentIntent?.metadata?.userId) || 1;
      console.log("userId ", userId);

      await prisma.user.update({
        where: {
          id: userId,
        },
        data: {
          tokens: {
            increment: 1,
          },
          paid: true,
        },
      });

      break;
    case "payment_method.attached":
      const paymentMethod = event.data.object;

      break;
    // ... handle other event types
    default:
      console.log(`Unhandled event type ${event.type}`);
  }

  // Return a response to acknowledge receipt of the event
  return NextResponse.json({ received: true });
}