{
  "event": "message.reply",
  "timestamp": "2026-04-15T12:00:00Z",
  "workspaceId": "org_abc123",
  "data": {
    "messageId": "msg_xyz789",
    "recipientPhone": "+19045551234",
    "message": "Yes, I'm interested!",
    "status": "received",
    "lineId": "line_001",
    "firstName": "Jane",
    "lastName": "Smith",
    "attachmentUrls": [],
    "attachmentNames": []
  }
}

const crypto = require('crypto');

function verifyWebhook(body, signature, secret) {
  const expected = crypto
    .createHmac('sha256', secret)
    .update(JSON.stringify(body))
    .digest('hex');
  return signature === expected;
}

if (event === 'message.fallback') {
  // Recipient doesn't have iMessage — send SMS via Twilio
  await twilio.messages.create({
    to: data.recipientPhone,
    from: '+1YOURTWILIONUMBER',
    body: data.message,
  });
}

if (event === 'message.reply') {
  // Update HubSpot contact with reply
  await hubspot.crm.contacts.basicApi.update(contactId, {
    properties: { last_reply: data.message, last_reply_date: data.timestamp }
  });
}