Skip to main content
API keys are subject to the following rate limits:
2 requests per second per API key. This is a default limit and can be increased upon request.
When you exceed the rate limit, you’ll receive a 429 Too Many Requests response with a retryAfter field indicating how many seconds to wait.

​
Rate Limit Headers

Each API response includes rate limit information: 
X-RateLimit-Limit: 120
X-RateLimit-Remaining: 115
X-RateLimit-Reset: 1696075200

​
Handling Rate Limits

To prevent overwhelming the API, you should implement exponential backoff when receiving 429 errors: 
async function sendEmailWithRetry(data, maxRetries = 3) {
  for (let i = 0; i < maxRetries; i++) {
    try {
      const response = await sendEmail(data);
      return response;
    } catch (error) {
      if (error.status === 429 && i < maxRetries - 1) {
        const waitTime = Math.pow(2, i) * 1000; // Exponential backoff
        await new Promise((resolve) => setTimeout(resolve, waitTime));
      } else {
        throw error;
      }
    }
  }
}