curl --request GET \
  --url https://api.maesn.dev/accounting/customers/{contactId} \
  --header 'X-ACCOUNT-KEY: <x-account-key>' \
  --header 'X-API-KEY: <x-api-key>'

import requests

url = "https://api.maesn.dev/accounting/customers/{contactId}"

headers = {
    "X-API-KEY": "<x-api-key>",
    "X-ACCOUNT-KEY": "<x-account-key>"
}

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

print(response.text)

const options = {
  method: 'GET',
  headers: {'X-API-KEY': '<x-api-key>', 'X-ACCOUNT-KEY': '<x-account-key>'}
};

fetch('https://api.maesn.dev/accounting/customers/{contactId}', 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.maesn.dev/accounting/customers/{contactId}",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 30,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "GET",
  CURLOPT_HTTPHEADER => [
    "X-ACCOUNT-KEY: <x-account-key>",
    "X-API-KEY: <x-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://api.maesn.dev/accounting/customers/{contactId}"

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

	req.Header.Add("X-API-KEY", "<x-api-key>")
	req.Header.Add("X-ACCOUNT-KEY", "<x-account-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://api.maesn.dev/accounting/customers/{contactId}")
  .header("X-API-KEY", "<x-api-key>")
  .header("X-ACCOUNT-KEY", "<x-account-key>")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://api.maesn.dev/accounting/customers/{contactId}")

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

request = Net::HTTP::Get.new(url)
request["X-API-KEY"] = '<x-api-key>'
request["X-ACCOUNT-KEY"] = '<x-account-key>'

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

{
  "meta": {
    "warnings": [
      "Field not used by target system"
    ],
    "pagination": {
      "total": 125,
      "perPage": 50,
      "currentPage": 1,
      "totalPages": 3
    },
    "partialErrors": [
      {
        "code": "FILE_UPLOAD_FAILED",
        "message": "Attachment invoice.pdf could not be uploaded to the target system."
      }
    ]
  },
  "data": {
    "id": "92c4f3a2-5b8e-4d1b-8a0c-9f6e7d2f3e4b",
    "addresses": [
      {
        "addressLine1": "Lucky street 1",
        "addressLine2": "2nd floor",
        "city": "Berlin",
        "countryCode": "DE",
        "postalCode": "10243",
        "type": "BILLING"
      }
    ],
    "bankAccounts": [
      {
        "bic": "COBADEFFXXX",
        "holder": "John Doe",
        "iban": "DE89370400440532013000",
        "sepa": true,
        "isMainAccount": true,
        "name": "Sparkasse"
      }
    ],
    "companyName": "maesn",
    "contactType": "CONTACT_PERSON",
    "contactPersons": [
      {
        "emailAddresses": [
          {
            "email": "john.doe@company.com",
            "type": "BUSINESS"
          }
        ],
        "firstName": "John",
        "lastName": "Doe",
        "phoneNumbers": [
          {
            "number": "+49 7163307056",
            "type": "MOBILE"
          }
        ],
        "salutation": "Mr"
      }
    ],
    "documentId": "Z1248601M",
    "emailAddresses": [
      {
        "email": "john.doe@company.com",
        "type": "BUSINESS"
      }
    ],
    "number": "1042",
    "phoneNumbers": [
      {
        "number": "+49 7163307056",
        "type": "MOBILE"
      }
    ],
    "projectId": "3",
    "updatedDate": "2018-01-01T13:00:00.000Z",
    "vatId": "DE123456789"
  }
}