curl --request GET \
  --url https://api-sandbox.revolv3.com/api/Customers \
  --header 'x-revolv3-token: <api-key>'

import requests

url = "https://api-sandbox.revolv3.com/api/Customers"

headers = {"x-revolv3-token": "<api-key>"}

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

print(response.text)

const options = {method: 'GET', headers: {'x-revolv3-token': '<api-key>'}};

fetch('https://api-sandbox.revolv3.com/api/Customers', 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-sandbox.revolv3.com/api/Customers",
  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-revolv3-token: <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-sandbox.revolv3.com/api/Customers"

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

	req.Header.Add("x-revolv3-token", "<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://api-sandbox.revolv3.com/api/Customers")
  .header("x-revolv3-token", "<api-key>")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://api-sandbox.revolv3.com/api/Customers")

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

request = Net::HTTP::Get.new(url)
request["x-revolv3-token"] = '<api-key>'

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

[
  {
    "customerId": 1,
    "merchantCustomerRefId": "1234-5678-9101",
    "firstName": "John",
    "lastName": "Doe"
  },
  {
    "customerId": 2,
    "merchantCustomerRefId": "5678-1234-9101",
    "firstName": "Jane",
    "lastName": "Doe"
  },
  {
    "customerId": 3,
    "merchantCustomerRefId": "9101-5678-1234",
    "firstName": "Jeremy",
    "lastName": "Doe"
  }
]

{
  "message": "Attempted to perform an unauthorized operation."
}

{
  "message": "Unable to find an entity with the provided data."
}