Send a welcome email from Clerk

import { verifyWebhook } from "@clerk/backend/webhooks";
import Courier from "@trycourier/courier";

const courier = new Courier({ apiKey: process.env.COURIER_API_KEY! });

export async function POST(request: Request) {
  let evt;
  try {
    // Throws on a bad signature or a replayed request.
    evt = await verifyWebhook(request);
  } catch {
    return new Response("Invalid signature", { status: 400 });
  }

  if (evt.type !== "user.created") {
    return new Response("Ignored", { status: 200 });
  }

  const { id, email_addresses, primary_email_address_id, first_name } = evt.data;

  // Match the primary id rather than taking [0]. A user with several
  // addresses can have the primary at any index.
  const email = email_addresses?.find((e) => e.id === primary_email_address_id)
    ?.email_address;

  if (!email) {
    return new Response("No email on user", { status: 200 });
  }

  // Use Clerk's id as the Courier user id so both systems agree.
  await courier.profiles.create(id, {
    profile: { email, given_name: first_name ?? undefined },
  });

  await courier.send.message({
    message: {
      to: { user_id: id },
      template: "nt_01kx4h2jdafq8bk9aftxak4b40",
      data: { name: first_name ?? "there" },
    },
  });

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