Rate Limits

Overview

CloudVNO API endpoints are rate limited to protect the platform and ensure fair usage for all customers. Rate limits are enforced per API key.

Default Limits

Endpoint Group	Requests per Second	Requests per Minute
Messages (SMS/MMS)	100	3,000
Voice calls	20	1,000
Phone Verification	50	2,000
Number lookups	100	5,000
Number provisioning	10	200
Proxy sessions	20	500

Rate Limit Headers

Every API response includes rate limit headers:

X-RateLimit-Limit: 100
X-RateLimit-Remaining: 87
X-RateLimit-Reset: 1709728800

• X-RateLimit-Limit: Maximum requests allowed in the current window
• X-RateLimit-Remaining: Requests remaining in the current window
• X-RateLimit-Reset: Unix timestamp when the current window resets

Handling 429 Responses

When you exceed the rate limit, the API returns HTTP 429 Too Many Requests:

{
  "error": {
    "code": "rate_limit_exceeded",
    "message": "Too many requests. Please slow down.",
    "retry_after": 2
  }
}

Implement exponential backoff in your code:

import time
import cloudvno
from cloudvno.exceptions import RateLimitError

def send_with_retry(client, **kwargs, max_retries=3):
    for attempt in range(max_retries):
        try:
            return client.messages.send(**kwargs)
        except RateLimitError as e:
            if attempt == max_retries - 1:
                raise
            wait = (2 ** attempt) + 0.1
            time.sleep(wait)

High-Volume Sending

For bulk sending operations (>100 messages/second), use our batch messaging API and contact us at sales@cloudvno.com to discuss higher throughput limits.

Throughput limits per number type:

• Long codes: 1 message/second per number
• Short codes: 500 messages/second
• Toll-free: 3 messages/second per number