Best OTP SMS Service Provider in India

curl -X POST https://api.getclickmedia.com/v1/sms/send \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "to": "+9198XXXXXXXX",
    "senderId": "GCMSMS",
    "templateId": "1707XXXXXXXXXXXXXXX",
    "message": "482913 is your OTP for login. Valid for 10 minutes. Do not share it. - GCMSMS",
    "route": "transactional"
  }'

{
  "event": "sms.failed",
  "messageId": "sms_7c3f21",
  "to": "+9198XXXXXXXX",
  "status": "failed",
  "route": "transactional",
  "timestamp": "2026-08-13T10:15:04Z"
}

// Express webhook: update the OTP attempt, never resend blindly
app.post("/webhooks/sms", express.json(), async (req, res) => {
  res.sendStatus(200); // acknowledge first
  const { messageId, status } = req.body;

  const attempt = await otpAttempts.findByMessageId(messageId);
  if (!attempt) return;                     // unknown or duplicate event

  await otpAttempts.update(attempt.id, { status });

  if (status === "failed") {
    // Let the user retry straight away instead of waiting out the timer,
    // and offer another channel on the next attempt
    await otpAttempts.update(attempt.id, { resendAllowedAt: new Date(), suggestChannel: "voice" });
  }
});