Rate Limits

The SMS API limits the number of requests that can be made from a single IP address.

Limit

The current limit is:

This means an IP address can make up to 300 requests per second.

Rate limit exceeded

When the rate limit is exceeded, the API returns HTTP 429.

{
  "success": false,
  "message": "Too many requests.",
  "error": "RATE_LIMIT_EXCEEDED",
  "data": null
}

The response also includes a Retry-After header.

HTTP/1.1 429 Too Many Requests
Retry-After: 1

The Retry-After value indicates how long your application should wait before making another request.

Handling rate limits

When you receive a 429 response:

1. Stop sending requests temporarily.
2. Read the Retry-After header.
3. Wait for the specified period.
4. Retry the request.

If the request is a retry of the same SMS operation, use the same Idempotency-Key.

Example

Request
    ↓
HTTP 429
    ↓
Read Retry-After
    ↓
Wait
    ↓
Retry using the same Idempotency-Key

Recommended approach

Applications sending large numbers of SMS messages should avoid sending requests continuously at the maximum rate.

Use a queue or controlled worker process to manage outgoing requests and automatically handle 429 responses.