Send email from Bun with SNDR.

Bun ships Node's APIs (node:crypto, fs, etc.) plus a fast native HTTP server (Bun.serve) and a tight Web-standards story. The SDK works without modification — install, instantiate, send. The recipes below use Bun.serve directly for the minimum viable server; pair with Hono or Elysia when you need richer routing.

1. Minimal Bun.serve send endpoint

   Bun.serve uses Web standards Request / Response. The SDK works exactly as on Node. Pair with a Bun-native router (Hono, Elysia) when you need more than a few routes.

   // server.ts
   import { Sndr, SndrError } from '@rkiza/sndr';
   
   const sndr = new Sndr(Bun.env.SNDR_API_KEY!);
   
   Bun.serve({
     port: 3000,
     async fetch(req) {
       const url = new URL(req.url);
       if (req.method === 'POST' && url.pathname === '/api/welcome') {
         const { email, name } = (await req.json()) as { email: string; name: string };
         try {
           const { id } = await sndr.emails.send({
             from: 'hello@yourdomain.com',
             to: email,
             subject: `Welcome, ${name}`,
             html: `<p>Thanks for joining us, ${name}.</p>`,
           });
           return Response.json({ id });
         } catch (err) {
           if (err instanceof SndrError) {
             return Response.json(
               { error: { code: err.code, message: err.message } },
               { status: (err.status >= 400 && err.status <= 599 ? err.status : 502) },
             );
           }
           throw err;
         }
       }
       return new Response('Not found', { status: 404 });
     },
   });
   
   console.log('listening on http://localhost:3000');

2. Webhook receiver

   Bun.serve gives you the Web standard Request directly — req.arrayBuffer() reads the raw bytes for HMAC verification before any JSON parse step touches them.

   import { verifyWebhookSignature } from '@rkiza/sndr';
   import type { WebhookEventPayload } from '@rkiza/sndr';
   
   Bun.serve({
     port: 3001,
     async fetch(req) {
       if (req.method !== 'POST' || new URL(req.url).pathname !== '/webhooks/sndr') {
         return new Response('not found', { status: 404 });
       }
       const raw = Buffer.from(await req.arrayBuffer());
       const ok = verifyWebhookSignature(
         raw,
         req.headers.get('x-sndr-signature') ?? '',
         Bun.env.SNDR_WEBHOOK_SECRET!,
       );
       if (!ok) return new Response('bad signature', { status: 400 });
   
       const event = JSON.parse(raw.toString('utf8')) as WebhookEventPayload;
       switch (event.type) {
         case 'email.delivered':
           // event.data.email_id, event.data.to: string[]
           break;
         case 'email.bounced':
           // event.data.email_id, event.data.error
           break;
         case 'email.unsubscribed':
           // event.data.addresses: string[]
           break;
       }
       return new Response('ok');
     },
   });

3. Run sends in a Bun cron / scheduled task

   Bun.serve has no scheduling — pair with `bun --watch` for dev, and cron / systemd timers / your platform's scheduler for production. Or use a queue (BullMQ + Bun Redis client).

   // scheduled/daily-digest.ts — run via cron: bun run scheduled/daily-digest.ts
   import { Sndr } from '@rkiza/sndr';
   
   const sndr = new Sndr(Bun.env.SNDR_API_KEY!);
   
   const users = await fetchActiveUsers();
   await Promise.all(
     users.map(async (user) => {
       await sndr.emails.send(
         {
           from: 'digest@yourdomain.com',
           to: user.email,
           subject: `Your daily digest, ${user.name.split(' ')[0]}`,
           html: renderDigest(user),
         },
         { idempotencyKey: `daily-digest-${user.id}-${new Date().toISOString().slice(0, 10)}` },
       );
     }),
   );
   
   function renderDigest(user: { id: string; name: string }): string {
     return `<p>Your digest for ${user.name}.</p>`;
   }
   async function fetchActiveUsers(): Promise<Array<{ id: string; email: string; name: string }>> {
     return [];
   }

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