Bulk SMS API, OTP SMS API, WhatsApp API & Email API for Developers

🛠 SMSGatewayHub Developer APIs — Full Overview

One account, one API key, every channel. Below is the complete SMSGatewayHub API suite — this page documents the Bulk SMS / OTP SMS API in full; click through for dedicated docs and pricing on the other channels.

🔑 Authentication

Every SMS API request requires your unique APIKey parameter. Generate a free key by registering an account, then find it in your dashboard under API Settings.

⚡ Throughput & SLA

Every account on the SMS gateway API gets a guaranteed baseline throughput, with a High Availability tier available for high-volume senders.

To upgrade to the HA Cluster infrastructure, contact support@smsgatewayhub.com.

🛡 Security & Trust

All API endpoints run behind SSL/TLS encryption with a Web Application Firewall (WAF), IP-based access restriction and brute-force monitoring.

Data Retention Policy

🧪 Live API Tester

Test the SMSGatewayHub API directly from your browser. Enter your credentials and send a real request to verify your integration.

Single SMS API — Bulk SMS API core endpoint

Send a single SMS to one recipient. Supports text, Unicode (Hindi/regional), Flash SMS, group delivery and scheduled delivery.

Parameters

https://www.smsgatewayhub.com/api/mt/SendSMS
  ?APIKey=yourapicode
  &senderid=TESTIN
  &channel=2
  &DCS=0
  &flashsms=0
  &number=91989xxxxxxx
  &text=test+message
  &route=1
  &EntityId=Registered-Entity-Id
  &dlttemplateid=Registered-DLT-Template-Id

https://www.smsgatewayhub.com/api/mt/SendSMS
  ?APIKey=yourapicode
  &senderid=TESTIN
  &channel=2
  &DCS=8
  &flashsms=0
  &number=91989xxxxxxx
  &text=%E0%A4%A8%E0%A4%AE%E0%A4%B8%E0%A5%8D%E0%A4%A4%E0%A5%87
  &route=1
  &EntityId=Registered-Entity-Id
  &dlttemplateid=Registered-DLT-Template-Id

https://www.smsgatewayhub.com/api/mt/SendSMS
  ?APIKey=yourapicode
  &senderid=TESTIN
  &channel=2
  &DCS=0
  &flashsms=1
  &number=91989xxxxxxx
  &text=test+message
  &route=1
  &EntityId=Registered-Entity-Id
  &dlttemplateid=Registered-DLT-Template-Id

Response

{"ErrorCode":"000","ErrorMessage":"Success","JobId":"20047",
"MessageData":[{"Number":"91989xxxxxxx","MessageId":"BqTiw66A2UGLFV3DnwHFLQ"}]}

Bulk SMS API

Send SMS to multiple recipients in one call. Pass comma-separated numbers in the number parameter — all other parameters match the Single SMS API.

https://www.smsgatewayhub.com/api/mt/SendSMS
  ?APIKey=yourapicode&senderid=TESTIN&channel=2&DCS=0&flashsms=0
  &number=91989xxxxxxx,91999xxxxxxx&text=test+message&route=1
  &EntityId=Registered-Entity-Id&dlttemplateid=Registered-DLT-Template-Id

Response

{"ErrorCode":"000","ErrorMessage":"Success","JobId":"20047",
"MessageData":[
  {"Number":"91989xxxxxxx","MessageId":"mvHdpSyS7UOs9hjxixQLvw"},
  {"Number":"91999xxxxxxx","MessageId":"PfivClgH20iG6G5R3usHwA"}
]}

OTP SMS API

The same endpoint powers OTP delivery for login, signup and 2FA flows — just set channel=OTP. OTP messages get the highest delivery priority and bypass DND filters, while still requiring a DLT-registered OTP template.

https://www.smsgatewayhub.com/api/mt/SendSMS
  ?APIKey=yourapicode&senderid=TESTIN&channel=OTP&DCS=0&flashsms=0
  &number=91989xxxxxxx&text=Your+OTP+is+123456&route=1
  &EntityId=Registered-Entity-Id&dlttemplateid=Registered-DLT-Template-Id

International SMS API

Send SMS to numbers worldwide with channel=INT and the full number including country code (no + prefix). EntityId and dlttemplateid are not required for international SMS.

https://www.smsgatewayhub.com/api/mt/SendSMS
  ?APIKey=yourapicode&senderid=TESTIN&channel=INT&DCS=0&flashsms=0
  &number=12093158246&text=test+message&route=1

Balance Check API

Check available SMS credits on your account in real time.

{"ErrorCode":"0","ErrorMessage":"Success","Balance":"9988"}

DLR Status API

Check delivery status for a sent message using the jobid returned by the Send SMS API.

{"ErrorCode":"0","ErrorMessage":"Success",
"DeliveryReports":[
  {"MessageId":"mvHdpSyS7UOs9hjxixQLvw","DeliveryStatus":"Delivered","DeliveryDate":"2026-08-28T06:17:00"}
]}

JSON API

Send SMS via HTTP POST with a JSON body. Set header Content-Type: application/json.

{
  "Account": {
    "APIkey": "your-api-key",
    "SenderId": "TESTIN",
    "Channel": "2",
    "DCS": "0",
    "EntityId": "your-entity-id"
  },
  "Messages": [
    { "Text": "Your message here", "DLTTemplateId": "your-template-id", "Number": "91989xxxxxxx" }
  ]
}

XML API

Send SMS via HTTP POST with an XML body. Set header Content-Type: application/xml.

<SmsQueue>
  <Account>
    <APIKey>your-api-key</APIKey>
    <SenderId>TESTIN</SenderId>
    <Channel>2</Channel>
    <EntityId>13011xxxxxxxx</EntityId>
    <DCS>0</DCS>
    <Route>1</Route>
  </Account>
  <Messages>
    <Message>
      <Number>91989xxxxxxx</Number>
      <Text>Your message here</Text>
      <DltTemplateId>130716xxxxxxxxx</DltTemplateId>
    </Message>
  </Messages>
</SmsQueue>

Short Link API

Embed trackable shortened URLs inside SMS text using #Link1#, #Link2# placeholders.

<Links>
  <Links><Link>www.example.com</Link></Links>
</Links>

Simple Voice SMS API

Send a text-to-speech (TTS) voice call to a single recipient. Supports Indian English and Hindi voices.

{
  "from": "919999999999",
  "to": "916666666666",
  "text": "Test Voice message.",
  "language": "en",
  "voice": { "name": "Joanna", "gender": "female" }
}

Response

{"messages":[{
  "to": "916666666666",
  "status": { "groupId": 1, "groupName": "PENDING", "name": "PENDING_ENROUTE" },
  "messageId": "2250be2d4219-3af1-78856-aabe-1362af1edfd2"
}]}

Multiple Voice SMS API

Send voice messages to multiple recipients in one request. Mix TTS text and audio file URLs within the same batch.

{
  "messages": [
    { "from": "919999999999", "to": ["916666666666","919999999998"], "audioFileUrl": "https://example.com/media.mp3" },
    { "from": "919999999999", "to": ["916666666666"], "text": "Hello world!", "language": "en", "voice": { "name": "Joanna", "gender": "female" } }
  ]
}

Fully Featured Voice API

Full-featured voice API with scheduling, DTMF input, call transfer, retry logic, machine detection, recording, and delivery webhooks.

Call Transfer — Any DTMF

[{ "if": "anyDtmf", "transferTo": "919999999999", "callTransferMaxDuration": 10 }]

Voice Delivery Reports

📞 Missed Call API

When an incoming missed call arrives at your toll-free or DID number, SMSGatewayHub forwards the call details to your webhook URL via GET request.

🐘 PHP Quick Start

Copy, paste, replace your credentials — this is the fastest way to send your first SMS from a PHP backend.

<?php
$apikey = "YourAPIkey";
$sender = "TESTIN";
$msg    = "YOUR MESSAGE HERE";
$num    = "91XXXXXXXXX";
$ms     = rawurlencode($msg);

$url = "https://www.smsgatewayhub.com/api/mt/SendSMS"
     . "?APIKey=$apikey&senderid=$sender&channel=2"
     . "&DCS=0&flashsms=0&number=$num&text=$ms&route=1";

$ch = curl_init($url);
curl_setopt($ch, CURLOPT_POST, 1);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
$response = curl_exec($ch);
curl_close($ch);

$result = json_decode($response, true);
echo $result['ErrorCode'] === '000'
    ? "SMS sent! Job ID: " . $result['JobId']
    : "Error: " . $result['ErrorMessage'];
?>

⚠️ API Response Error Codes

These codes are returned in the ErrorCode field of every API response.

✓️ Special Character Encoding

URL-encode these characters when passing them in query string parameters (especially the text field). Use PHP's rawurlencode() or JavaScript's encodeURIComponent() to handle this automatically.

🗣 Voice Languages

✦ = Default voice for language

🔗 Related APIs & Channels

SMSGatewayHub is a full messaging platform — pair the SMS API with these channels from the same account.

❓ Frequently Asked Questions