{
  "error": {
    "code": "insufficient_credits",
    "message": "Your account has 0 credits remaining. Top up at https://app.zupertry.com/billing."
  }
}

async function submitTryOn(modelUrl, garmentUrl) {
  const res = await fetch('https://app.zupertry.com/v1/tryon', {
    method: 'POST',
    headers: {
      Authorization: `Bearer ${process.env.ZUPERTRY_API_KEY}`,
      'Content-Type': 'application/json',
    },
    body: JSON.stringify({
      model_image_url: modelUrl,
      garment_image_url: garmentUrl,
    }),
  });

  if (!res.ok) {
    const { error } = await res.json();

    switch (error.code) {
      case 'insufficient_credits':
        throw new Error('Please top up your credits at app.zupertry.com/billing');
      case 'rate_limit_exceeded':
        // Retry after 60s
        await new Promise((r) => setTimeout(r, 60_000));
        return submitTryOn(modelUrl, garmentUrl);
      case 'invalid_api_key':
      case 'api_key_revoked':
        throw new Error('API key is invalid. Check your ZUPERTRY_API_KEY environment variable.');
      default:
        throw new Error(`Zupertry error [${error.code}]: ${error.message}`);
    }
  }

  return res.json();
}