curl --request POST \
  --url https://api.16tms.com/api/v1/external/users \
  --header 'Content-Type: application/json' \
  --header 'X-API-KEY: <api-key>' \
  --data '
{
  "externalId": "user_123",
  "displayName": "John Doe",
  "email": "user@example.com"
}
'

import requests

url = "https://api.16tms.com/api/v1/external/users"

payload = {
    "externalId": "user_123",
    "displayName": "John Doe",
    "email": "user@example.com"
}
headers = {
    "X-API-KEY": "<api-key>",
    "Content-Type": "application/json"
}

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

print(response.text)

const options = {
  method: 'POST',
  headers: {'X-API-KEY': '<api-key>', 'Content-Type': 'application/json'},
  body: JSON.stringify({externalId: 'user_123', displayName: 'John Doe', email: 'user@example.com'})
};

fetch('https://api.16tms.com/api/v1/external/users', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

<?php

$curl = curl_init();

curl_setopt_array($curl, [
  CURLOPT_URL => "https://api.16tms.com/api/v1/external/users",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 30,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "POST",
  CURLOPT_POSTFIELDS => json_encode([
    'externalId' => 'user_123',
    'displayName' => 'John Doe',
    'email' => 'user@example.com'
  ]),
  CURLOPT_HTTPHEADER => [
    "Content-Type: application/json",
    "X-API-KEY: <api-key>"
  ],
]);

$response = curl_exec($curl);
$err = curl_error($curl);

curl_close($curl);

if ($err) {
  echo "cURL Error #:" . $err;
} else {
  echo $response;
}

package main

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

func main() {

	url := "https://api.16tms.com/api/v1/external/users"

	payload := strings.NewReader("{\n  \"externalId\": \"user_123\",\n  \"displayName\": \"John Doe\",\n  \"email\": \"user@example.com\"\n}")

	req, _ := http.NewRequest("POST", url, payload)

	req.Header.Add("X-API-KEY", "<api-key>")
	req.Header.Add("Content-Type", "application/json")

	res, _ := http.DefaultClient.Do(req)

	defer res.Body.Close()
	body, _ := io.ReadAll(res.Body)

	fmt.Println(string(body))

}

HttpResponse<String> response = Unirest.post("https://api.16tms.com/api/v1/external/users")
  .header("X-API-KEY", "<api-key>")
  .header("Content-Type", "application/json")
  .body("{\n  \"externalId\": \"user_123\",\n  \"displayName\": \"John Doe\",\n  \"email\": \"user@example.com\"\n}")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://api.16tms.com/api/v1/external/users")

http = Net::HTTP.new(url.host, url.port)
http.use_ssl = true

request = Net::HTTP::Post.new(url)
request["X-API-KEY"] = '<api-key>'
request["Content-Type"] = 'application/json'
request.body = "{\n  \"externalId\": \"user_123\",\n  \"displayName\": \"John Doe\",\n  \"email\": \"user@example.com\"\n}"

response = http.request(request)
puts response.read_body

{
  "success": true,
  "message": "User registered successfully",
  "data": {
    "userId": "72241a59-3638-4c7c-8105-81774de2c900",
    "externalId": "user_123",
    "isNewUser": true,
    "username": "user_123"
  },
  "meta": {
    "traceId": "00-0b9a33deb55060719389707d91fe66e4-39ac3a60dea035aa-00",
    "elapsedMs": 8.42,
    "serverTimestamp": "2026-02-09T06:07:53.9323654Z"
  }
}

{
  "success": false,
  "message": "Invalid API key",
  "errors": [
    {
      "field": "externalId",
      "message": "This field is required"
    }
  ],
  "meta": {
    "traceId": "<string>",
    "serverTimestamp": "2023-11-07T05:31:56Z"
  }
}

{
  "success": false,
  "message": "Invalid API key",
  "errors": [
    {
      "field": "externalId",
      "message": "This field is required"
    }
  ],
  "meta": {
    "traceId": "<string>",
    "serverTimestamp": "2023-11-07T05:31:56Z"
  }
}

{
  "success": false,
  "message": "Invalid API key",
  "errors": [
    {
      "field": "externalId",
      "message": "This field is required"
    }
  ],
  "meta": {
    "traceId": "<string>",
    "serverTimestamp": "2023-11-07T05:31:56Z"
  }
}