Understand and handle API rate limits

HTTP/1.1 200 OK
X-RateLimit-Limit: 100
X-RateLimit-Remaining: 95
X-RateLimit-Reset: 1701964800

async function makeRequestWithRetry(url, options, maxRetries = 5) {
  let retries = 0;

  while (retries < maxRetries) {
    try {
      const response = await fetch(url, options);

      if (response.status === 429) {
        // Rate limit exceeded
        const waitTime = Math.min(
          Math.pow(2, retries) * 1000, // Exponential backoff
          60000 // Max 60 seconds
        );

        console.log(`Rate limited. Waiting ${waitTime}ms...`);
        await new Promise(resolve => setTimeout(resolve, waitTime));
        retries++;
        continue;
      }

      return response;
    } catch (error) {
      if (retries === maxRetries - 1) throw error;
      retries++;
    }
  }

  throw new Error('Max retries exceeded');
}

// Usage
const response = await makeRequestWithRetry(
  `${BASE_URL}/v1/chat/completions`,
  {
    method: 'POST',
    headers: {
      'Authorization': 'Bearer YOUR_API_KEY',
      'Content-Type': 'application/json'
    },
    body: JSON.stringify({
      model: 'gemini-2.5-flash',
      messages: [{ role: 'user', content: 'Hello!' }]
    })
  }
);