Rate Limits & API Best Practices

Rate Limits

Sakura SMS enforces rate limits to ensure fair usage and platform stability.

Current Limits

• API Requests: 50 requests per second per API key
• SMS Throughput: ~50 SMS per second (carrier-dependent)
• Webhook Deliveries: No outbound limit (we push as events occur)

Handling Rate Limits

When you exceed the rate limit, the API returns 429 Too Many Requests with a Retry-After header indicating when to retry.

Best Practices

• Implement exponential backoff — Wait 1s, 2s, 4s, 8s between retries
• Batch recipients — Send to multiple numbers in one API call instead of making separate calls per number
• Check balance first — Call GET /api/v1/balance before large sends to avoid 402 errors
• Use webhooks — Don't poll for delivery status; let webhooks push updates to you
• Cache responses — Cache balance and status responses for short periods
• Use idempotency — Include unique campaign names to prevent duplicate sends on retries