How to Send Emails with Firebase Cloud Functions

import { onDocumentCreated } from "firebase-functions/v2/firestore";
import { Mailofly } from "@mailofly/node";

const mailofly = new Mailofly({
  apiKey: process.env.MAILOFLY_API_KEY!,
});

export const onNewUserCreated = onDocumentCreated(
  {
    document: "users/{userId}",
    secrets: ["MAILOFLY_API_KEY"],
  },
  async (event) => {
    const snapshot = event.data;
    if (!snapshot) return;

    const userData = snapshot.data();

    await mailofly.emails.send({
      from: "Welcome <hello@yourdomain.com>",
      to: [userData.email],
      subject: `Welcome to our platform, ${userData.displayName || "friend"}!`,
      html: "<p>We're thrilled to have you here. Your account is verified.</p>",
      tags: [{ name: "source", value: "firebase_auth" }],
    });
  }
);