Alle Zahlungsarten.
Ein System.

// app/api/checkout/route.ts
import Stripe from "stripe";
import { NextResponse } from "next/server";

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

export async function POST(req: Request) {
  const { priceId } = await req.json();

  const session = await stripe.checkout.sessions.create({
    mode: "payment",
    payment_method_types: ["card", "sepa_debit", "klarna"],
    line_items: [{ price: priceId, quantity: 1 }],
    success_url: `${process.env.NEXT_PUBLIC_URL}/success`,
    cancel_url: `${process.env.NEXT_PUBLIC_URL}/cancel`,
  });

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

// app/api/webhooks/stripe/route.ts
import Stripe from "stripe";
import { headers } from "next/headers";

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

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

  const event = stripe.webhooks.constructEvent(
    body,
    sig,
    process.env.STRIPE_WEBHOOK_SECRET!
  );

  switch (event.type) {
    case "checkout.session.completed":
      const session = event.data.object;
      // Bestellung bestaetigen & E-Mail senden
      await fulfillOrder(session);
      break;
    case "payment_intent.payment_failed":
      // Kunden benachrichtigen
      await notifyCustomer(event.data.object);
      break;
  }

  return new Response("OK", { status: 200 });
}

// app/api/subscribe/route.ts
import Stripe from "stripe";
import { NextResponse } from "next/server";

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

export async function POST(req: Request) {
  const { email, priceId } = await req.json();

  // Kunde in Stripe anlegen oder finden
  const customer = await stripe.customers.create({ email });

  const session = await stripe.checkout.sessions.create({
    mode: "subscription",
    customer: customer.id,
    line_items: [{ price: priceId, quantity: 1 }],
    success_url: `${process.env.NEXT_PUBLIC_URL}/willkommen`,
    cancel_url: `${process.env.NEXT_PUBLIC_URL}/preise`,
  });

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