zerodrop-client

Email verification infrastructure for CI pipelines and AI agents.

Send a verification email. Catch it at the edge. Get email.otp and email.magicLink back — auto-extracted, no regex, no Docker, no signup.

const email = await mail.waitForLatest(inbox);

email.otp        // "123456" — auto-extracted
email.magicLink  // "https://..." — no regex needed

Documentation · GitHub · Status

Install

npm install zerodrop-client

Test Isolation

Every inbox is isolated by default. generateInbox() returns a unique address on every call — no shared state, no pools, no configuration needed.

Zero cross-test contamination. Every test run gets a cryptographically isolated inbox that expires automatically after 30 minutes.

This means parallel CI builds work out of the box — 10 workers, 10 inboxes, zero race conditions.

Zero-Auth Mode (Local Development)

import { ZeroDrop } from 'zerodrop-client';

const mail = new ZeroDrop();
const inbox = mail.generateInbox();
// → "swift-x7k29@zerodrop-sandbox.online"

const email = await mail.waitForLatest(inbox, { timeout: 10000 });
console.log(email.subject);   // "Reset your password"
console.log(email.otp);       // "123456" — auto-extracted, no regex needed
console.log(email.magicLink); // "https://..." — auto-extracted verification link

CI Pipeline Mode (Playwright / Cypress)

import { ZeroDrop } from 'zerodrop-client';

const mail = new ZeroDrop(process.env.ZERODROP_API_KEY);

test('password reset flow', async ({ page }) => {
  const inbox = mail.generateInbox();

  await page.goto('/forgot-password');
  await page.fill('[name="email"]', inbox);
  await page.click('[type="submit"]');

  const email = await mail.waitForLatest(inbox, { timeout: 15000 });
  expect(email.subject).toContain('Reset your password');

  // No regex — magicLink is auto-extracted at the edge
  await page.goto(email.magicLink);
});

OTP Auto-Extraction

ZeroDrop extracts OTP codes and magic links at the edge before emails reach your test suite. No regex required.

const email = await mail.waitForLatest(inbox);

// Auto-extracted fields
email.otp        // "123456" — 4-8 digit verification code
email.magicLink  // "https://app.com/verify?token=abc" — verification/reset link

// Raw body still available if you need it
email.body       // Full plain-text body

Both fields are null if not detected in the email.

Email Filtering

Filter emails by sender, subject, body, or extracted fields. Useful when multiple emails land in the same inbox.

// Only match emails from a specific sender
const email = await mail.waitForLatest(inbox, {
  filter: { from: 'noreply@yourapp.com' }
});

// Only match emails with a specific subject
const email = await mail.waitForLatest(inbox, {
  filter: { subject: 'Verify your email' }
});

// Only match emails that contain an OTP
const email = await mail.waitForLatest(inbox, {
  filter: { hasOtp: true }
});

// Only match emails that contain a magic link
const email = await mail.waitForLatest(inbox, {
  filter: { hasMagicLink: true }
});

// Combine multiple filters
const email = await mail.waitForLatest(inbox, {
  timeout: 15000,
  filter: {
    from: 'noreply@yourapp.com',
    subject: 'Reset',
    hasMagicLink: true
  }
});

All string filters are case-insensitive partial matches.

Parallel CI Runs

Inbox generation is client-side — no API call, no throttling. 50 parallel tests generate 50 inboxes instantly.

// Safe to run in parallel — generateInbox() is local
const inboxes = Array.from({ length: 50 }, () => mail.generateInbox());

The rate limit applies to the polling endpoint — 20 requests per 10 seconds per IP on the free tier. For heavy parallel usage, stagger waitForLatest() calls slightly:

// Stagger polls to avoid burst on shared IP
const results = await Promise.all(
  inboxes.map((inbox, i) =>
    new Promise(resolve => setTimeout(resolve, i * 100))
      .then(() => mail.waitForLatest(inbox, { timeout: 15000 }))
  )
);

For CI pipelines with 20+ parallel tests, use a Workspace API key — dedicated rate limit bucket, not shared with the public pool.

Webhook Mode (Staging Servers)

const mail = new ZeroDrop(process.env.ZERODROP_API_KEY);

await mail.onReceived('qa-test@yourcompany.com', 'https://your-server.com/webhook');
// ZeroDrop POSTs the email JSON to your URL when it arrives

API

new ZeroDrop(apiKey?, options?)

• apiKey — optional. Omit for free sandbox mode.
• options.baseUrl — override the API base URL.

mail.generateInbox(): string

Returns a ready-to-use email address instantly. No network request.

mail.fetchLatest(inbox, filter?): Promise<ZeroDropEmail | null>

Returns the latest email matching the filter, or null if inbox is empty.

mail.waitForLatest(inbox, options?): Promise<ZeroDropEmail>

Uses SSE for sub-second email delivery. Falls back to polling automatically. Throws ZeroDropTimeoutError on timeout.

• options.timeout — ms to wait (default: 10000)
• options.pollInterval — ms between polls in fallback mode (default: 2000)
• options.sse — set false to force polling mode (default: true)
• options.filter — filter emails by sender, subject, body, otp, magicLink

mail.onReceived(inbox, webhookUrl): Promise<{ registered: boolean }>

Registers a webhook. Requires API key (Workspace tier).

Types

interface ZeroDropEmail {
  id: string;
  from: string;
  to: string;
  subject: string;
  body: string;
  rawBody: string;
  receivedAt: Date;
  otp: string | null;        // Auto-extracted OTP code (4-8 digits)
  magicLink: string | null;  // Auto-extracted verification/reset link
}

interface ZeroDropFilter {
  from?: string;             // Partial match on sender address
  subject?: string;          // Partial match on subject line
  body?: string;             // Partial match on email body
  hasOtp?: boolean;          // Only match emails with an extracted OTP
  hasMagicLink?: boolean;    // Only match emails with an extracted magic link
}

Error Handling

import { ZeroDrop, ZeroDropTimeoutError } from 'zerodrop-client';

try {
  const email = await mail.waitForLatest(inbox, { timeout: 10000 });
} catch (err) {
  if (err instanceof ZeroDropTimeoutError) {
    console.error('No email received — check your app is sending correctly');
  }
}

Free vs Workspace

	Free	Workspace
Inbox generation	✓	✓
OTP auto-extraction	✓	✓
Magic link extraction	✓	✓
Email filtering	✓	✓
Email retention	30 min	Extended
Custom domains	✗	✓
API key	✗	✓
Webhooks	✗	✓
AI spam filter	On	Off

Get a Workspace at zerodrop.dev

License

MIT