The SNDR alternative to Resend.

Resend brought taste back to email APIs and we admire the work. SNDR optimises for slightly different things: a multi-MTA pool with circuit-breaker routing so a single bad-day provider can't take down your sends, signed webhooks with exponential-backoff retries and a replay button in the admin, and a transparent Merchant-of-Record billing model for international teams. If you've outgrown a single-vendor delivery path or want operator tooling that matches the product surface, this page is for you.

Drawn from public documentation and pricing as of build time. We try to keep this fair — file an issue if anything is wrong.

1. 1

   Install the SDK

   Drop in @rkiza/sndr alongside (or in place of) the resend package.

   pnpm add @rkiza/sndr

2. 2

   Swap the import + constructor

   The shape is intentionally the same — a typed Sndr class with sndr.emails.send().

   // before
   import { Resend } from 'resend';
   const resend = new Resend(process.env.RESEND_API_KEY!);
   
   // after
   import { Sndr } from '@rkiza/sndr';
   const sndr = new Sndr(process.env.SNDR_API_KEY!);

3. 3

   Rename the send call

   Same fields. The SDK validates apiKey on construction so a bad env var fails loudly instead of returning 401 from the first request.

   const { id } = await sndr.emails.send({
     from: 'hello@yourdomain.com',
     to: 'customer@example.com',
     subject: 'Welcome aboard',
     html: '<p>Thanks for joining us.</p>',
   });

4. 4

   Verify webhooks

   Mount express.raw() (not express.json()), then verify with the shipped helper. Replay-defended out of the box.

   import { verifyWebhookSignature } from '@rkiza/sndr';
   
   app.post('/webhooks/sndr', express.raw({ type: 'application/json' }), (req, res) => {
     const ok = verifyWebhookSignature(req.body, req.header('x-sndr-signature') ?? '', process.env.SNDR_WEBHOOK_SECRET!);
     if (!ok) return res.status(400).send('bad signature');
     // ...
   });

5. 5

   Add your sending domain

   Same DNS records you already have for Resend (SPF, DKIM, DMARC). Add them once in the SNDR dashboard, verify in under 5 minutes.