npm install telnyx

import Telnyx from 'telnyx';

const client = new Telnyx({
  apiKey: process.env['TELNYX_API_KEY'], // This is the default and can be omitted
});

try {
  const response = await client.messages.send({
      to: '+18445550001',
      from: '+18005550101',
      text: 'Hello from Telnyx!',
  });
} catch (err) {
  if (err instanceof Telnyx.APIConnectionError) {
    console.error('Network error — check connectivity and retry');
  } else if (err instanceof Telnyx.RateLimitError) {
    const retryAfter = err.headers?.['retry-after'] || 1;
    await new Promise(r => setTimeout(r, retryAfter * 1000));
  } else if (err instanceof Telnyx.APIError) {
    console.error(`API error ${err.status}: ${err.message}`);
    if (err.status === 422) {
      console.error('Validation error — check required fields and formats');
    }
  }
}

const response = await client.messages.send({
    to: '+18445550001',
    from: '+18005550101',
    text: 'Hello from Telnyx!',
});

console.log(response.data);

const response = await client.messages.sendWithAlphanumericSender({
  from: 'MyCompany',
  messaging_profile_id: '182bd5e5-6e1a-4fe4-a799-aa6d9a6ab26e',
  text: 'Hello from Telnyx!',
  to: '+13125550001',
});

console.log(response.data);

// In your webhook handler (e.g., Express — use raw body, not parsed JSON):
app.post('/webhooks', express.raw({ type: 'application/json' }), async (req, res) => {
  try {
    const event = await client.webhooks.unwrap(req.body.toString(), {
      headers: req.headers,
    });
    // Signature valid — event is the parsed webhook payload
    console.log('Received event:', event.data.event_type);
    res.status(200).send('OK');
  } catch (err) {
    console.error('Webhook verification failed:', err.message);
    res.status(400).send('Invalid signature');
  }
});

const response = await client.messages.sendGroupMms({
  from: '+13125551234',
  to: ['+18655551234', '+14155551234'],
    text: 'Hello from Telnyx!',
});

console.log(response.data);

const response = await client.messages.sendLongCode({
    from: '+18445550001', to: '+13125550002',
    text: 'Hello from Telnyx!',
});

console.log(response.data);

const response = await client.messages.sendNumberPool({
  messaging_profile_id: 'abc85f64-5717-4562-b3fc-2c9600000000',
  to: '+13125550002',
    text: 'Hello from Telnyx!',
});

console.log(response.data);

const response = await client.messages.sendShortCode({
    from: '+18445550001', to: '+18445550001',
    text: 'Hello from Telnyx!',
});

console.log(response.data);

const response = await client.messages.schedule({
    to: '+18445550001',
    from: '+18005550101',
    text: 'Appointment reminder',
    sendAt: '2025-07-01T15:00:00Z',
});

console.log(response.data);

const response = await client.messages.sendWhatsapp({
  from: '+13125551234',
  to: '+13125551234',
  whatsapp_message: {},
});

console.log(response.data);