Reference

Rate Limits

Sendexa enforces per-endpoint and global rate limits to ensure fair usage. Limits are applied per API key.

Limits are per API key

All limits below apply per API key per minute. If you need higher limits, contact support@sendexa.co.

Limits by Endpoint

Channel	Endpoint	Req / min	Burst
SMS — single send	POST /v1/sms/send	120	20
SMS — bulk send	POST /v1/sms/bulk	20	5
OTP — request	POST /v1/otp/request	60	10
OTP — verify	POST /v1/otp/verify	120	20
WhatsApp — send	POST /v1/whatsapp/send	60	10
Email — single send	POST /v1/email/send	120	20
Email — bulk send	POST /v1/email/bulk	20	5
Voice — call / TTS	POST /v1/voice/*	30	5
Status lookups	GET /v1/*/status/:id	300	50
Global (all routes)	All endpoints	500	—

Burst — the maximum number of requests allowed in a single second before token-bucket smoothing kicks in.

Rate Limit Headers

Every API response includes these headers so you can track your current usage window.

Bash

HTTP/1.1 200 OK
X-RateLimit-Limit:     120
X-RateLimit-Remaining: 87
X-RateLimit-Reset:     1716038460

Header	Description
X-RateLimit-Limit	Maximum requests allowed in the current window.
X-RateLimit-Remaining	Requests remaining before the limit resets.
X-RateLimit-Reset	Unix timestamp (seconds) when the window resets.
Retry-After	Seconds to wait before retrying — present only on 429 responses.

429 — Too Many Requests

When you exceed a limit, the API returns a 429 with a body explaining the violation.

JSON

HTTP/1.1 429 Too Many Requests
Retry-After: 14

{
  "success": false,
  "message": "Rate limit exceeded. Try again in 14 seconds.",
  "code": "RATE_LIMIT_EXCEEDED",
  "requestId": "req_abc123"
}

Handling Rate Limits

Use exponential backoff with jitter when you receive a 429. Always respect the Retry-After header rather than blindly retrying.

TypeScript

async function sendWithRetry(payload: SendSmsRequest, maxRetries = 3) {
  for (let attempt = 0; attempt <= maxRetries; attempt++) {
    try {
      return await client.sms.send(payload);
    } catch (err) {
      if (err instanceof SendexaError && err.status === 429) {
        if (attempt === maxRetries) throw err;

        // Respect Retry-After if present, otherwise exponential backoff
        const retryAfter = err.retryAfter ?? Math.pow(2, attempt);
        const jitter = Math.random() * 1000;
        await new Promise((r) => setTimeout(r, retryAfter * 1000 + jitter));
        continue;
      }
      throw err; // non-rate-limit errors bubble up immediately
    }
  }
}

For bulk sends, spread requests over time rather than firing all at once.
Cache status lookups — poll at 5-second intervals rather than hammering continuously.
Use webhooks for delivery updates instead of polling the status endpoint.