API & messaging rate limits
SendyStack rate-limits at two layers: the API itself (requests / minute) and the underlying WhatsApp Cloud API (messages / 24h). Both scale with your plan.
Per-plan API limits
| Plan | Steady (req / min) | Burst (req / min) | Outbound messages |
|---|---|---|---|
| Basic | 100 | 200 | 10,000 outbound |
| Pro | 1,000 | 2,000 | 100,000 outbound |
| Business | 2,500 | 5,000 | 300,000 outbound |
Rate-limit headers
Every response carries three headers so your client can self-throttle.
X-RateLimit-Limit: 1000 X-RateLimit-Remaining: 943 X-RateLimit-Reset: 1716840060
429 responses
A request that exceeds the limit returns 429 Too Many Requests with a Retry-After header in seconds. Use exponential backoff and respect X-RateLimit-Reset for the next safe send time.
Meta's messaging tiers
WhatsApp Cloud API has its own 24-hour conversation tiers (250 / 1K / 10K / 100K / unlimited). Hitting Meta's tier returns a delivery failure with reason 131056. Tiers grow automatically as your delivery quality stays high.