PHP client https://openexchangerates.org/
Via Composer
$ composer require orlac/openexchangerates
$appId = '<your_app_id>';
$baseUri = 'https://openexchangerates.org/api/';
$client = new ApiClient(new CurlConnect($appId, $baseUri));
$rsp = $client->request(Endpoints::Latest->value, new DtoBuilder());
var_dump($rsp);