{
  "error": {
    "code": "RATE_LIMITED",
    "message": "Too many requests. Please try again later.",
    "requestId": "550e8400-e29b-41d4-a716-446655440000"
  }
}

async function requestWithBackoff(
  fn: () => Promise<Response>,
  maxRetries = 5,
) {
  for (let attempt = 0; attempt < maxRetries; attempt++) {
    const response = await fn();
    if (response.status !== 429) return response;
    const seconds = Number(response.headers.get("Retry-After"));
    const waitMs = Number.isFinite(seconds) && seconds > 0
      ? seconds * 1000
      : 1000 * Math.pow(2, attempt);
    await new Promise((resolve) => setTimeout(resolve, waitMs));
  }
  throw new Error("Rate limit retries exhausted");
}