curl --request GET \
  --url https://letterby.com/api/v4/contacts \
  --header 'apiKey: <api-key>'

import requests

url = "https://letterby.com/api/v4/contacts"

headers = {"apiKey": "<api-key>"}

response = requests.get(url, headers=headers)

print(response.text)

const options = {method: 'GET', headers: {apiKey: '<api-key>'}};

fetch('https://letterby.com/api/v4/contacts', 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://letterby.com/api/v4/contacts",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 30,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "GET",
  CURLOPT_HTTPHEADER => [
    "apiKey: <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"
	"net/http"
	"io"
)

func main() {

	url := "https://letterby.com/api/v4/contacts"

	req, _ := http.NewRequest("GET", url, nil)

	req.Header.Add("apiKey", "<api-key>")

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

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

	fmt.Println(string(body))

}

HttpResponse<String> response = Unirest.get("https://letterby.com/api/v4/contacts")
  .header("apiKey", "<api-key>")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://letterby.com/api/v4/contacts")

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

request = Net::HTTP::Get.new(url)
request["apiKey"] = '<api-key>'

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

{
  "data": {
    "contacts": [
      {
        "id": "<string>",
        "email": "<string>",
        "firstName": "<string>",
        "lastName": "<string>",
        "phoneNumber": "<string>",
        "createdAt": "2023-11-07T05:31:56Z",
        "points": 123,
        "referrals": 123,
        "listId": "<string>",
        "isVerified": true,
        "unsubscribed": true,
        "data": {},
        "address": "<string>",
        "isGDPR": true,
        "name": "<string>",
        "instagram": "<string>",
        "twitter": "<string>",
        "website": "<string>",
        "company": "<string>",
        "country": "<string>",
        "city": "<string>",
        "list": {
          "id": "<string>",
          "name": "<string>",
          "url": "<string>",
          "mode": "<string>",
          "referrals": true,
          "color": "<string>",
          "title": "<string>",
          "desc": "<string>"
        },
        "audiences": "<array>",
        "referralLink": "<string>",
        "privateLink": "<string>"
      }
    ],
    "pagination": {
      "total": 123,
      "pages": 123,
      "currentPage": 123,
      "perPage": 123
    }
  }
}

{
  "error": 123,
  "message": "<string>"
}

{
  "error": 123,
  "message": "<string>"
}