X-RateLimit-Limit: 1000
X-RateLimit-Remaining: 998
X-RateLimit-Reset: 1788333600

HTTP/1.1 429 Too Many Requests
Content-Type: application/problem+json
X-Request-ID: req_01JAY8FVDM6CH4R3X9Q2T7K5NP
Retry-After: 45

{
  "type": "https://api.oncanary.com/errors/rate_limit_exceeded",
  "title": "Rate Limit Exceeded",
  "status": 429,
  "detail": "Rate limit exceeded. Retry after 45 seconds.",
  "request_id": "req_01JAY8FVDM6CH4R3X9Q2T7K5NP",
  "code": "rate_limit_exceeded"
}

const sleep = (milliseconds) => new Promise((resolve) => setTimeout(resolve, milliseconds));

async function fetchCanary(url, options, attempts = 4) {
  for (let attempt = 0; attempt < attempts; attempt += 1) {
    const response = await fetch(url, options);
    if (response.status !== 429) return response;

    const retryAfter = Number(response.headers.get('Retry-After') ?? 60);
    const jitter = Math.floor(Math.random() * 500);
    await sleep(retryAfter * 1000 + jitter);
  }

  throw new Error('Canary API remained rate limited');
}