Send Email from Google Cloud Functions (Node.js)

import { AhaSendClient } from "@ahasend/sdk";
try {
  const client = AhaSendClient.fromEnv();
  const result = await client.messages.send({
    from: { email: process.env.AHASEND_FROM },
    recipients: [{ email: "recipient@example.com" }],
    subject: "My first sandbox email",
    text_content: "Hello from AhaSend",
    sandbox: true,
  });
  const statuses = result.data.map((entry) => entry.status);
  console.log({ statuses });
  if (!statuses.length || statuses.some((s) => !["queued", "scheduled"].includes(s)))
    throw new Error("A recipient was rejected");
} catch {
  console.error("Sandbox send failed; check your credentials, sender and account.");
  process.exitCode = 1;
}

const { createHash, timingSafeEqual } = require("node:crypto");
const { AhaSendClient } = require("@ahasend/sdk");
const digest = (value) => createHash("sha256").update(value).digest();
let client;
exports.sendEmail = async (body, authorization = "") => {
  const token = process.env.SEND_TOKEN;
  if (!token) return [500, { error: "Missing server configuration" }];
  if (!timingSafeEqual(digest(authorization), digest(`Bearer ${token}`)))
    return [401, { error: "Unauthorized" }];
  if (!body || typeof body.event_id !== "string" ||
      !/^[A-Za-z0-9_-]{8,64}$/.test(body.event_id))
    return [400, { error: "event_id must be 8-64 letters, digits, _ or -" }];
  const mode = process.env.AHASEND_DELIVERY_MODE || "sandbox";
  if (!["sandbox", "live"].includes(mode) ||
      !["AHASEND_API_KEY", "AHASEND_ACCOUNT_ID", "AHASEND_FROM", "AHASEND_TO"]
        .every((name) => process.env[name]))
    return [500, { error: "Missing or invalid server configuration" }];
  try {
    client ||= AhaSendClient.fromEnv();
    const result = await client.messages.send({
      from: { email: process.env.AHASEND_FROM },
      recipients: [{ email: process.env.AHASEND_TO }],
      subject: "Welcome", text_content: "Your account is ready.",
      sandbox: mode === "sandbox",
    }, { idempotencyKey: `${mode}-welcome-${body.event_id}` });
    const statuses = result.data.map((item) => item.status);
    if (!statuses.length || statuses.some((s) => !["queued", "scheduled"].includes(s)))
      return [422, { error: "A recipient was rejected" }];
    return [202, { statuses }];
  } catch {
    return [502, { error: "Email request failed" }];
  }
};

const functions = require("@google-cloud/functions-framework");
const { sendEmail } = require("./send-email.cjs");
functions.http("sendEmail", async (req, res) => {
  if (req.method !== "POST") return res.status(405).end();
  if ((req.rawBody?.length || 0) > 16384) return res.status(413).end();
  if (!req.is("application/json")) return res.status(415).end();
  const [status, result] = await sendEmail(req.body, req.get("authorization") || "");
  res.status(status).json(result);
});