Migrate from Mailosaur

import MailosaurClient from "mailosaur";

const mailosaur = new MailosaurClient(process.env.MAILOSAUR_API_KEY);
const serverId = process.env.MAILOSAUR_SERVER_ID;
const emailAddress = `signup-${Date.now()}@${serverId}.mailosaur.net`;

await startSignup(emailAddress); // your application sends the email

const message = await mailosaur.messages.get(
  serverId,
  { sentTo: emailAddress, subject: "Verify" },
  { timeout: 30000 },
);
const code = message.html.codes[0].value;
const link = message.html.links[0].href;

const origin = process.env.INBOXSPEC_API_URL ?? "https://api.inboxspec.com";

async function inboxspec(path, body) {
  const response = await fetch(origin + path, {
    method: "POST",
    headers: {
      Authorization: "Bearer " + process.env.INBOXSPEC_API_KEY,
      "Content-Type": "application/json",
    },
    body: JSON.stringify(body),
  });
  // Authentication, quota and validation problems are HTTP errors, never timeouts.
  if (!response.ok) throw new Error(`InboxSpec ${response.status}: ${await response.text()}`);
  return response.json();
}

const inbox = await inboxspec("/v1/inboxes/for-run", { run_id: `signup-${Date.now()}` });

await startSignup(inbox.address); // your application sends the email

const result = await inboxspec("/v1/messages/wait", {
  inbox: inbox.address,
  match: { subject_contains: "Verify", has_code: true },
  timeout_ms: 30000,
});
if (result.status === "timeout") throw new Error(result.hint);
const code = result.message.codes[0];
const link = result.message.links.find((candidate) => candidate.kind === "verify")?.href;