@profullstack/emailer

Mass emailer for Profullstack apps. Wraps Resend's batch API with a simple interface for sending bulk emails. Zero runtime dependencies.

Installation

npm install @profullstack/emailer

Usage

import { createEmailer } from '@profullstack/emailer';

const emailer = createEmailer({
  resendApiKey: process.env.RESEND_API_KEY,
});

Send a single email

const result = await emailer.send({
  from: 'App <noreply@example.com>',
  to: 'user@example.com',
  subject: 'Hello',
  html: '<p>Hello world</p>',
  text: 'Hello world',
});

// { sent: true, id: 're_...' }

Send a bulk email

const result = await emailer.sendBulk({
  from: 'App <noreply@example.com>',
  to: ['alice@example.com', 'bob@example.com', ...],
  subject: 'Big announcement',
  html: '<p>Something exciting</p>',
  text: 'Something exciting',
  batchSize: 100,  // default: 100 (Resend's batch limit)
  delayMs: 500,    // optional delay between batches
});

// { sent: 2, failed: 0, errors: [] }

Per-recipient personalization

Pass a function for html or text to customize per recipient:

await emailer.sendBulk({
  from: 'App <noreply@example.com>',
  to: emails,
  subject: 'Your weekly digest',
  html: (email) => `<p>Hi ${email}, here's your digest…</p>`,
});

API

createEmailer(config)

Option	Type	Description
resendApiKey	string	Resend API key (required)
defaultFrom	string	Default from address used when not provided per-call

emailer.send(opts)

Option	Type	Description
from	string	Sender (falls back to defaultFrom)
to	string	Recipient
subject	string	Subject line
html	string	HTML body
text	string?	Plain-text body
replyTo	string?	Reply-to address
headers	Record<string,string>?	Extra headers (e.g. List-Unsubscribe)
attachments	Array<{filename,content}>?	Base64-encoded attachments

Returns { sent: boolean, id?: string, error?: string }.

emailer.sendBulk(opts)

Same as send but to is string[], html/text can be a (email: string) => string function, plus:

Option	Type	Default	Description
batchSize	number	100	Recipients per Resend batch call
delayMs	number	0	Delay between batch calls

Returns { sent: number, failed: number, errors: Array<{email, error}> }.

License

MIT © Profullstack Inc