429 and Quota Retry Simulator

• Attempt 1: retry (550ms)
• Attempt 2: retry (1191ms)
• Attempt 3: retry (2054ms)
• Attempt 4: success (4165ms)
• Attempt 4: quota_stop

async function handleLimitedResponse(response) {
  if (response.status !== 429) {
    return response;
  }

  const body = await response.json();
  const code = body.error?.code;

  if (code === "rate_limit_exceeded") {
    const retryAfter = Number(response.headers.get("retry-after") ?? 1);
    await new Promise((resolve) => setTimeout(resolve, retryAfter * 1000));
    return null; // signal caller to retry
  }

  if (code?.includes("quota_exceeded")) {
    await recordQuotaPressure(response.headers.get("x-unlimitedcodex-quota-state"));
    return response; // do not immediately retry
  }

  return response;
}