Rate Limiting

HTTP/1.1 429 Too Many Requests
Retry-After: 4

{
  "error_code": "TOO_MANY_REQUESTS",
  "message": "Rate limit exceeded. Retry after 4 seconds"
}

async function requestWithBackoff(fn, maxRetries = 5) {
  for (let attempt = 0; attempt < maxRetries; attempt++) {
    const response = await fn();
    if (response.status !== 429) return response;
    const retryAfter = parseInt(response.headers.get("Retry-After") ?? "1", 10);
    await new Promise(r => setTimeout(r, retryAfter * 1000));
  }
  throw new Error("Rate limit retries exhausted");
}