429 Too Many Requests

Implement exponential backoff

async function fetchWithRetry(url: string, retries = 3) {
  for (let i = 0; i < retries; i++) {
    const res = await fetch(url);
    if (res.status !== 429) return res;
    const delay = Math.pow(2, i) * 1000;
    await new Promise(r => setTimeout(r, delay));
  }
  throw new Error('Rate limited');
}

Wait exponentially longer between retries: 1s, 2s, 4s.