Rate limits

Every response carries three headers:

Header	Meaning
RateLimit-Limit	Requests allowed in the current window
RateLimit-Remaining	Requests left in the window
RateLimit-Reset	Seconds until the window resets

Over the limit, the API answers 429 rate_limited with a Retry-After header in seconds. The server SDKs wait and retry for you.

Limits depend on your plan. If you send in bursts, batch send counts a batch of up to 1,000 messages as one request.