A2P Messaging API rate limits

Every A2P Messaging endpoint enforces a ceiling of requests per 60-second window. The counter is kept per account and per endpoint: all the tokens of an account share one counter for each endpoint, so spreading traffic across several tokens does not add capacity. If you need more throughput on a specific endpoint, open a ticket with the expected peak rate and we will raise the ceiling on your account.

Limits per endpoint

With so few reads allowed on GET /sms and GET /sms/{id}, track delivery through DLR webhooks instead of polling. For counts over a day or a month, read SMS traffic metrics instead of paging through GET /sms; its figures refresh periodically, so calling it more often than they change gains nothing.

Reading the headers

Every response includes three headers with the current window state. Log them in production — they are the cheapest way to spot a client that is about to hit the wall.

X-RateLimit-Limit      1200
X-RateLimit-Remaining  1195
X-RateLimit-Reset      1893452400

When you hit the limit

Requests that exceed the window return 429 Too Many Requests. The body is the plain text You exceeded the rate limit (not JSON); the X-RateLimit-Reset header tells you when to retry.

What's next

• Errors — every status code you might receive, including 429.
• API Reference — per-endpoint documentation.