SMSlenz API Integration Guide for Developers

<?php
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, "https://mail.smslenz.lk/api/send-bulk-sms");
curl_setopt($ch, CURLOPT_POST, true);
curl_setopt($ch, CURLOPT_HTTPHEADER, ['Content-Type: application/json']);
curl_setopt($ch, CURLOPT_POSTFIELDS, json_encode([
    'user_id'   => '12',
    'api_key'   => 'YOUR_API_KEY',
    'sender_id' => 'SMSlenzDEMO',
    'contacts'  => ['+9476XXXXXXX', '+9475XXXXXXX'],
    'message'   => 'Welcome to bulk sms API!',
]));
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);

$response = curl_exec($ch);
curl_close($ch);

echo $response;

fetch("https://mail.smslenz.lk/api/send-bulk-sms", {
    method: "POST",
    headers: { "Content-Type": "application/json" },
    body: JSON.stringify({
        user_id: "12",
        api_key: "YOUR_API_KEY",
        sender_id: "SMSlenzDEMO",
        contacts: ["+9476XXXXXXX", "+9475XXXXXXX"],
        message: "Welcome to bulk sms API!"
    })
})
    .then(res => res.json())
    .then(data => console.log(data))
    .catch(err => console.error(err));

import requests

url = "https://mail.smslenz.lk/api/send-bulk-sms"
payload = {
    "user_id": "12",
    "api_key": "YOUR_API_KEY",
    "sender_id": "SMSlenzDEMO",
    "contacts": ["+9476XXXXXXX", "+9475XXXXXXX"],
    "message": "Welcome to bulk sms API!"
}

response = requests.post(url, json=payload)
print(response.json())

<?php
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, "https://mail.smslenz.lk/api/account-status");
curl_setopt($ch, CURLOPT_POST, true);
curl_setopt($ch, CURLOPT_POSTFIELDS, http_build_query([
    'user_id' => '12',
    'api_key' => 'YOUR_API_KEY',
]));
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);

$response = curl_exec($ch);
curl_close($ch);

echo $response;

fetch("https://mail.smslenz.lk/api/account-status", {
    method: "POST",
    headers: { "Content-Type": "application/json" },
    body: JSON.stringify({
        user_id: "12",
        api_key: "YOUR_API_KEY"
    })
})
    .then(res => res.json())
    .then(data => console.log(data))
    .catch(err => console.error(err));

import requests

url = "https://mail.smslenz.lk/api/account-status"
payload = {
    "user_id": "12",
    "api_key": "YOUR_API_KEY"
}

response = requests.post(url, data=payload)
print(response.json())

<?php
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, "https://mail.smslenz.lk/api/save-contact");
curl_setopt($ch, CURLOPT_POST, true);
curl_setopt($ch, CURLOPT_POSTFIELDS, http_build_query([
    'user_id' => '12',
    'api_key' => 'YOUR_API_KEY',
    'contact' => '+9476XXXXXXX',
    'name'    => 'Kamal Perera',
    'group'   => 'VIP Customers',
]));
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);

$response = curl_exec($ch);
curl_close($ch);

echo $response;

fetch("https://mail.smslenz.lk/api/save-contact", {
    method: "POST",
    headers: { "Content-Type": "application/json", "Accept": "application/json" },
    body: JSON.stringify({
        user_id: "12",
        api_key: "YOUR_API_KEY",
        contact: "+9476XXXXXXX",
        name: "Kamal Perera",
        group: "VIP Customers"
    })
})
    .then(res => res.json())
    .then(data => console.log(data))
    .catch(err => console.error(err));

import requests

url = "https://mail.smslenz.lk/api/save-contact"
payload = {
    "user_id": "12",
    "api_key": "YOUR_API_KEY",
    "contact": "+9476XXXXXXX",
    "name": "Kamal Perera",
    "group": "VIP Customers"
}

response = requests.post(url, data=payload)
print(response.json())

<?php
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, "https://mail.smslenz.lk/api/reload-credit");
curl_setopt($ch, CURLOPT_POST, true);
curl_setopt($ch, CURLOPT_HTTPHEADER, ['Content-Type: application/json']);
curl_setopt($ch, CURLOPT_POSTFIELDS, json_encode([
    'user_id'          => '12',
    'api_key'          => 'YOUR_API_KEY',
    'amount'           => 5000,
    'client_reference' => 'INV-1001',
    'callback_url'     => 'https://example.com/smslenz-callback',
]));
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);

$response = json_decode(curl_exec($ch), true);
curl_close($ch);

// Save $response['data']['order_id'], then send the payer to checkout:
header('Location: ' . $response['data']['payment_url']);

fetch("https://mail.smslenz.lk/api/reload-credit", {
    method: "POST",
    headers: { "Content-Type": "application/json" },
    body: JSON.stringify({
        user_id: "12",
        api_key: "YOUR_API_KEY",
        amount: 5000,
        client_reference: "INV-1001",
        callback_url: "https://example.com/smslenz-callback"
    })
})
    .then(res => res.json())
    .then(data => {
        // Save data.data.order_id, then open checkout
        window.location.href = data.data.payment_url;
    })
    .catch(err => console.error(err));

import requests

url = "https://mail.smslenz.lk/api/reload-credit"
payload = {
    "user_id": "12",
    "api_key": "YOUR_API_KEY",
    "amount": 5000,
    "client_reference": "INV-1001",
    "callback_url": "https://example.com/smslenz-callback"
}

data = requests.post(url, json=payload).json()
print(data["data"]["order_id"], data["data"]["payment_url"])

<?php
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, "https://mail.smslenz.lk/api/payment-status");
curl_setopt($ch, CURLOPT_POST, true);
curl_setopt($ch, CURLOPT_POSTFIELDS, http_build_query([
    'user_id'  => '12',
    'api_key'  => 'YOUR_API_KEY',
    'order_id' => 'PRU3FTX7HUJP8RAHY4',
]));
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);

$response = json_decode(curl_exec($ch), true);
curl_close($ch);

if ($response['data']['status'] === 'paid') {
    // Credit has been added to your account
}

fetch("https://mail.smslenz.lk/api/payment-status", {
    method: "POST",
    headers: { "Content-Type": "application/json" },
    body: JSON.stringify({
        user_id: "12",
        api_key: "YOUR_API_KEY",
        order_id: "PRU3FTX7HUJP8RAHY4"
    })
})
    .then(res => res.json())
    .then(data => console.log(data.data.status))
    .catch(err => console.error(err));

import requests

url = "https://mail.smslenz.lk/api/payment-status"
payload = {
    "user_id": "12",
    "api_key": "YOUR_API_KEY",
    "order_id": "PRU3FTX7HUJP8RAHY4"
}

response = requests.post(url, data=payload)
print(response.json()["data"]["status"])

const crypto = require("crypto");
const express = require("express");
const app = express();

// Use the raw body: the signature covers the exact bytes we sent.
app.post("/smslenz-callback", express.raw({ type: "application/json" }), (req, res) => {
    const sig = Object.fromEntries(
        (req.get("X-SMSlenz-Signature") || "").split(",").map(part => part.split("="))
    );
    const expected = crypto.createHmac("sha256", "YOUR_API_KEY")
        .update(`${sig.t}.${req.body}`)
        .digest("hex");

    const valid = sig.v1 && sig.v1.length === expected.length
        && crypto.timingSafeEqual(Buffer.from(expected), Buffer.from(sig.v1))
        && Math.abs(Date.now() / 1000 - Number(sig.t)) <= 300;
    if (!valid) return res.sendStatus(400);

    const event = JSON.parse(req.body);
    // Skip event.event_id if you've already processed it, then handle event.event
    res.sendStatus(200);
});

import hashlib, hmac, json, time
from flask import Flask, abort, request

app = Flask(__name__)

@app.post("/smslenz-callback")
def smslenz_callback():
    body = request.get_data()  # raw bytes, exactly as sent
    sig = dict(part.split("=", 1) for part in request.headers.get("X-SMSlenz-Signature", "").split(",") if "=" in part)

    expected = hmac.new(b"YOUR_API_KEY", f"{sig.get('t')}.".encode() + body, hashlib.sha256).hexdigest()
    if not hmac.compare_digest(expected, sig.get("v1", "")) or abs(time.time() - int(sig.get("t", 0))) > 300:
        abort(400)

    event = json.loads(body)
    # Skip event["event_id"] if you've already processed it, then handle event["event"]
    return "", 200