{
  "event": "tts.completed",
  "timestamp": "2026-07-16T10:00:00Z",
  "workspace_id": "ws_abc123",
  "data": {
    "job_id": "job_xyz789",
    "status": "completed",
    "output_url": "https://cdn.voicelab360.com/...",
    "credits_used": 1240,
    "duration_ms": 3800
  }
}

const crypto = require('crypto');

function verifyWebhook(payload, signature, secret) {
  const expected = crypto
    .createHmac('sha256', secret)
    .update(payload)
    .digest('hex');
  return crypto.timingSafeEqual(
    Buffer.from(expected),
    Buffer.from(signature)
  );
}