@usezend/node

Official Node.js/TypeScript client for the Zend messaging platform. Send SMS, WhatsApp, email, and voice messages — and manage message templates — from a single, typed client.

📚 Read the docs →

Installation

npm i @usezend/node

Requires Node.js 18 or later (uses the global fetch and FormData APIs).

Usage

Create a client with your API key:

import { Zend } from '@usezend/node';

const zend = new Zend('sent_live_...');

The API key can also be supplied via the ZEND_API_KEY environment variable, in which case you can construct the client with no arguments:

const zend = new Zend();

You can override the base URL (e.g. for a staging environment) or the request timeout, in milliseconds, via options — or the ZEND_BASE_URL environment variable:

const zend = new Zend('sent_live_...', {
  baseUrl: 'https://staging.api.tryzend.com',
  timeout: 30_000,
});

Note: baseUrl defaults to https://api.tryzend.com, and timeout defaults to 30s.

Every method returns a promise that resolves to { data, error } — see Errors below.

Send SMS / WhatsApp

Send a plain-text SMS:

const sms = await zend.messages.send({
  to: '+233201234567',
  body: 'Hello from Zend!',
  preferredChannels: ['sms'],
  senderId: 'MyBrand',
  fallbackEnabled: true,
  priority: 'high',
  deliveryPriority: 'speed',
  webhookUrl: 'https://your-app.com/webhooks/zend',
});

if (sms.error) throw sms.error;
console.log(`Message ${sms.data.id} (${sms.data.status})`);

Send over WhatsApp with a template, falling back to SMS:

await zend.messages.send({
  to: '+233201234567',
  templateId: 'welcome',
  templateParams: { first_name: 'John' },
  preferredChannels: ['whatsapp', 'sms'],
  fallbackEnabled: true,
  senderId: 'MyBrand',
});

Media (images, documents) on WhatsApp is defined in the approved template itself, not passed at send time.

Send to many recipients in one call:

await zend.messages.sendBulk({
  messages: [
    { to: '+233201234567', body: 'Hi Ama!' },
    { to: '+233207654321', body: 'Your code is 123456', templateParams: { code: '123456' } },
  ],
  preferredChannels: ['sms'],
  senderId: 'MyBrand',
  fallbackEnabled: true,
  webhookUrl: 'https://your-app.com/webhooks/zend',
});

Other messages methods: get(id), list(params?), cancel(id), retry(id).

Send Email

const email = await zend.emails.send({
  from: '[email protected]',
  to: '[email protected]',
  subject: 'Hello world',
  html: '<p>It works!</p>',
  text: 'It works!',
});

if (email.error) throw email.error;
console.log(`Email ${email.data.id} sent`);

Attach files with attachments — content is a Buffer or base64 string:

await zend.emails.send({
  from: '[email protected]',
  to: '[email protected]',
  subject: 'Your invoice',
  html: '<p>Invoice attached.</p>',
  attachments: [{ filename: 'invoice.pdf', content: pdfBuffer, contentType: 'application/pdf' }],
});

Limits: at most 10 attachments, 7 MB total.

Other emails methods: get(id), list(params?).

Send Voice

Send a call using text-to-speech, falling back to SMS if it isn't answered:

await zend.voice.send({
  recipients: ['+233201234567'],
  text: 'Your order has shipped.',
  voice: 'female',
  retry: true,
  callbackUrl: 'https://your-app.com/webhooks/voice',
  fallback: {
    sms: true,
    smsText: 'Your order has shipped.',
    senderId: 'MyBrand',
  },
});

Or play a pre-recorded audio file (a hosted MP3/WAV):

await zend.voice.send({
  recipients: ['+233201234567'],
  voiceUrl: 'https://cdn.example.com/message.mp3',
  fallback: { sms: true, smsText: 'You have a new message.' },
});

To send a local audio file, upload it first with zend.voice.upload(file, filename) and pass the returned url as voiceUrl.

Other voice methods: get(batchId), list(params?), upload(file, filename).

Templates

Templates are read-only from this SDK — list and fetch templates managed elsewhere:

const templates = await zend.templates.list({
  category: 'transactional',
  status: 'active',
  limit: 20,
  offset: 0,
});

console.log(`You have ${templates.data?.total ?? 0} templates`);

const template = await zend.templates.get('welcome');
console.log(template.data?.name);

list() accepts optional filters: { category?, status?, limit?, offset? }.

Errors

Every SDK method resolves — it never throws for API or network errors. The result is always one of:

{ data: T; error: null } | { data: null; error: ZendError }

Check error before using data:

const sms = await zend.messages.send({ to: '+233201234567', body: 'Hello!' });

if (sms.error) {
  throw sms.error;
}

console.log(sms.data.id);

ZendError extends Error and adds:

• name — e.g. "api_error", "timeout", "application_error"
• statusCode — HTTP status code, when available
• code — provider error code, when available

Full example

See examples/quickstart.ts for a complete, type-checked walkthrough of sending SMS, WhatsApp, email, and voice messages, plus listing templates.