Creating and consuming PHP+JSON webservice - I can’t make the configuration

Question

I’m making a webservice, without any framework, using PHP+JSON, with localhost xampp initially, so I’ll put it on some cloud server.

I created in xampp/htdocs two folders, "client" and "vendor", in the future 'client' will be on one server and 'vendor' in another, where in client will be the access of the user sending data through a form via Curl, and the supplier will receive this data and provide information for return in the customer interface. For now I am not using database, but soon I will complete, I believe that for this initial mechanism is not necessary bd.

To process the form data sent by the client, I did it as follows:

$url = "http://127.0.0.1/ws/fornecedor/wsClientRequire.php";    

  $cURL = curl_init($url);

  curl_setopt($cURL, CURLOPT_RETURNTRANSFER, true);

  // Definimos um array seguindo o padrão:
  //  '<name do input>' => '<valor inserido>'
  $dados = array(
    'nome' => 'John da silva',
    'email' => '[email protected]',
    'mensagem' => 'Testando o cURL!'
  );

  // Iremos usar o método POST
  curl_setopt($cURL, CURLOPT_POST, true);

  // Definimos quais informações serão enviadas pelo POST (array)
  curl_setopt($cURL, CURLOPT_POSTFIELDS, $dados);

  $resultado = curl_exec($cURL);

  $resposta = curl_getinfo($cURL, CURLINFO_HTTP_CODE);

  curl_close($cURL);

  if ($resposta == '404') {
        echo 'O site está fora do ar (ERRO 404)!';
  } else {
        echo 'Parece que está tudo bem...';
  }

    //var_dump(json_decode($jsonRet, true)); //com var_dump aparece NULL

    $retorno = json_decode($jsonRet);
    $success = $retorno->data->success;                                                                             
    echo " \n success: ".$success;

---

In this passage:

$retorno = json_decode($jsonRet);
    $success = $retorno->data->success;                                                                               
    echo " \n success: ".$success;

I was hoping to receive the information contained in the supplier’s file... but that didn’t happen... Then I would like to know how to do this part of the web service configuration. I did so at the vendor:

$success = "Recebido com sucesso.";
 $message = null;
 $dados = array();

    header('Content-Type: application/json; charset=utf-8');
    echo json_encode(
        array(
            'success' => $success,
            'message' => $message,
            'dados'   => $dados
        )
    );

    exit;

---

The communication between customer and supplier did not take place as desired... someone knows how to solve???

To clarify my question... in the "supplier" that is the last code I posted, how do I read the data that the customer sent via Curl? and how do I make a return available, which will be presented in the customer interface? As I send headers via Curl in the "client" file, in this headers in the Curl setopt it would be necessary to send a kind of token for access authorization, and how do I read this header token in the vendor file?