Libraries & SDKs

The API is a clean REST + JSON interface, so it works from any language with an HTTP client — no SDK required. Every endpoint page in these docs includes ready-to-paste examples in eight languages:

Language	HTTP client used in examples
cURL	—
Node.js	Built-in fetch (Node 18+)
Python	requests
PHP	curl extension
Ruby	net/http (stdlib)
Java	java.net.http.HttpClient (Java 11+)
Go	net/http (stdlib)
.NET	HttpClient (C#)

Pick your language once in any code block — the choice follows you across the entire site.

The full loop in your language

Send a message:

cURL

curl -X POST https://restlink23telecom.com/api/v1/sms/send \
  -H "X-API-Key: $API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
  "to": [
    "+14155551234"
  ],
  "message": "Your verification code is 847291",
  "sender_id": "MyApp"
}'

Node.js

const res = await fetch('https://restlink23telecom.com/api/v1/sms/send', {
  method: 'POST',
  headers: { 'X-API-Key': process.env.API_KEY, 'Content-Type': 'application/json' },
  body: JSON.stringify({
    "to": [
      "+14155551234"
    ],
    "message": "Your verification code is 847291",
    "sender_id": "MyApp"
  }),
});

if (!res.ok) {
  const err = await res.json();
  throw new Error(`${err.error_code}: ${err.description}`);
}
const data = await res.json();
console.log(data);

Python

import os
import requests

res = requests.post(
    "https://restlink23telecom.com/api/v1/sms/send",
    headers={"X-API-Key": os.environ["API_KEY"]},
    json={
        "to": ["+14155551234"],
        "message": "Your verification code is 847291",
        "sender_id": "MyApp"
    },
)
res.raise_for_status()
print(res.json())

PHP

<?php
$ch = curl_init('https://restlink23telecom.com/api/v1/sms/send');
curl_setopt_array($ch, [
    CURLOPT_CUSTOMREQUEST  => 'POST',
    CURLOPT_RETURNTRANSFER => true,
    CURLOPT_HTTPHEADER     => ['X-API-Key: ' . getenv('API_KEY'), 'Content-Type: application/json'],
    CURLOPT_POSTFIELDS     => json_encode([
        'to' => ['+14155551234'],
        'message' => 'Your verification code is 847291',
        'sender_id' => 'MyApp'
    ]),
]);

$response = curl_exec($ch);
$status   = curl_getinfo($ch, CURLINFO_HTTP_CODE);
curl_close($ch);

if ($status !== 200) {
    throw new Exception("HTTP $status: $response");
}
$data = json_decode($response, true);
print_r($data);

Ruby

require "net/http"
require "json"

uri = URI("https://restlink23telecom.com/api/v1/sms/send")
req = Net::HTTP::Post.new(uri)
req["X-API-Key"] = ENV.fetch("API_KEY")
req["Content-Type"] = "application/json"
req.body = {
  to: ["+14155551234"],
  message: "Your verification code is 847291",
  sender_id: "MyApp"
}.to_json

res = Net::HTTP.start(uri.hostname, uri.port, use_ssl: true) { |http| http.request(req) }
raise "HTTP #{res.code}: #{res.body}" unless res.is_a?(Net::HTTPSuccess)

puts JSON.parse(res.body)

Java

import java.net.URI;
import java.net.http.HttpClient;
import java.net.http.HttpRequest;
import java.net.http.HttpResponse;

HttpClient client = HttpClient.newHttpClient();

HttpRequest request = HttpRequest.newBuilder()
    .uri(URI.create("https://restlink23telecom.com/api/v1/sms/send"))
    .header("X-API-Key", System.getenv("API_KEY"))
    .header("Content-Type", "application/json")
    .POST(HttpRequest.BodyPublishers.ofString("""
        {
          "to": [
            "+14155551234"
          ],
          "message": "Your verification code is 847291",
          "sender_id": "MyApp"
        }"""))
    .build();

HttpResponse<String> response = client.send(request, HttpResponse.BodyHandlers.ofString());
System.out.println(response.body());

Go

package main

import (
  "fmt"
  "io"
  "net/http"
  "os"
  "strings"
)

func main() {
  payload := strings.NewReader(`{
  "to": [
    "+14155551234"
  ],
  "message": "Your verification code is 847291",
  "sender_id": "MyApp"
}`)

  req, err := http.NewRequest("POST", "https://restlink23telecom.com/api/v1/sms/send", payload)
  if err != nil {
    panic(err)
  }
  req.Header.Set("X-API-Key", os.Getenv("API_KEY"))
  req.Header.Set("Content-Type", "application/json")

  res, err := http.DefaultClient.Do(req)
  if err != nil {
    panic(err)
  }
  defer res.Body.Close()

  data, _ := io.ReadAll(res.Body)
  fmt.Println(string(data))
}

.NET

using System.Text;

using var client = new HttpClient();
client.DefaultRequestHeaders.Add("X-API-Key",
    Environment.GetEnvironmentVariable("API_KEY"));

var json = """
{
  "to": [
    "+14155551234"
  ],
  "message": "Your verification code is 847291",
  "sender_id": "MyApp"
}
""";
var content = new StringContent(json, Encoding.UTF8, "application/json");
var response = await client.PostAsync("https://restlink23telecom.com/api/v1/sms/send", content);

response.EnsureSuccessStatusCode();
Console.WriteLine(await response.Content.ReadAsStringAsync());

Check its status:

cURL

curl https://restlink23telecom.com/api/v1/sms/status/api_42_1743667200123456789_a3f8b2c1d9e45f67 \
  -H "X-API-Key: $API_KEY"

Node.js

const res = await fetch('https://restlink23telecom.com/api/v1/sms/status/api_42_1743667200123456789_a3f8b2c1d9e45f67', {
  method: 'GET',
  headers: { 'X-API-Key': process.env.API_KEY },
});

if (!res.ok) {
  const err = await res.json();
  throw new Error(`${err.error_code}: ${err.description}`);
}
const data = await res.json();
console.log(data);

Python

import os
import requests

res = requests.get(
    "https://restlink23telecom.com/api/v1/sms/status/api_42_1743667200123456789_a3f8b2c1d9e45f67",
    headers={"X-API-Key": os.environ["API_KEY"]},
)
res.raise_for_status()
print(res.json())

PHP

<?php
$ch = curl_init('https://restlink23telecom.com/api/v1/sms/status/api_42_1743667200123456789_a3f8b2c1d9e45f67');
curl_setopt_array($ch, [
    CURLOPT_RETURNTRANSFER => true,
    CURLOPT_HTTPHEADER     => ['X-API-Key: ' . getenv('API_KEY')],
]);

$response = curl_exec($ch);
$status   = curl_getinfo($ch, CURLINFO_HTTP_CODE);
curl_close($ch);

if ($status !== 200) {
    throw new Exception("HTTP $status: $response");
}
$data = json_decode($response, true);
print_r($data);

Ruby

require "net/http"
require "json"

uri = URI("https://restlink23telecom.com/api/v1/sms/status/api_42_1743667200123456789_a3f8b2c1d9e45f67")
req = Net::HTTP::Get.new(uri)
req["X-API-Key"] = ENV.fetch("API_KEY")

res = Net::HTTP.start(uri.hostname, uri.port, use_ssl: true) { |http| http.request(req) }
raise "HTTP #{res.code}: #{res.body}" unless res.is_a?(Net::HTTPSuccess)

puts JSON.parse(res.body)

Java

import java.net.URI;
import java.net.http.HttpClient;
import java.net.http.HttpRequest;
import java.net.http.HttpResponse;

HttpClient client = HttpClient.newHttpClient();

HttpRequest request = HttpRequest.newBuilder()
    .uri(URI.create("https://restlink23telecom.com/api/v1/sms/status/api_42_1743667200123456789_a3f8b2c1d9e45f67"))
    .header("X-API-Key", System.getenv("API_KEY"))
    .GET()
    .build();

HttpResponse<String> response = client.send(request, HttpResponse.BodyHandlers.ofString());
System.out.println(response.body());

Go

package main

import (
  "fmt"
  "io"
  "net/http"
  "os"
)

func main() {
  req, err := http.NewRequest("GET", "https://restlink23telecom.com/api/v1/sms/status/api_42_1743667200123456789_a3f8b2c1d9e45f67", nil)
  if err != nil {
    panic(err)
  }
  req.Header.Set("X-API-Key", os.Getenv("API_KEY"))

  res, err := http.DefaultClient.Do(req)
  if err != nil {
    panic(err)
  }
  defer res.Body.Close()

  data, _ := io.ReadAll(res.Body)
  fmt.Println(string(data))
}

.NET

using System.Text;

using var client = new HttpClient();
client.DefaultRequestHeaders.Add("X-API-Key",
    Environment.GetEnvironmentVariable("API_KEY"));

var response = await client.GetAsync("https://restlink23telecom.com/api/v1/sms/status/api_42_1743667200123456789_a3f8b2c1d9e45f67");

response.EnsureSuccessStatusCode();
Console.WriteLine(await response.Content.ReadAsStringAsync());

For webhook receivers in Python, Node.js and PHP, see the delivery webhook examples.

Package availability

Official TypeScript, Python and PHP SDK packages are not publicly distributed yet. Do not install similarly named third-party packages and assume they are maintained by 23 Telecom.

Today, use the eight-language examples above or generate a typed client from the OpenAPI 3.1 specification. Both routes call the same documented REST contract and work with free sandbox keys.

AI agents

The official MCP server is publicly available as a version-pinned npm package and adds send-safety controls for AI clients.

Integration tips that save support tickets

• Store the key in an environment variable like the examples do — rotating keys then never touches code.
• Treat messages[].message_id as your join key between send responses, status polls and webhook events.
• Handle 429 with backoff (rate limits) and monitor credit_blocked before large sends (balance).
• Make webhook handlers idempotent — retries deliver duplicates by design.