Facebook - Messaging webhook keeps infinitely looping the callback php file

while my page recive any notification .. the callback file infinitely running itself without stopping
here is the code:

require_once 'vendor/autoload.php';   
$fb = new \Facebook\Facebook([
  'app_id' => '{app-id}',           
  'app_secret' => '{app_secret}',   
  'graph_api_version' => 'v5.0',
]);
$feedData = file_get_contents('php://input');
$data = json_decode($feedData);
if ($data->object == "page") {   
  try {
    $response = $fb->post(
      '/me/messages',
      array (
        'recipient' => '{
          "id": "{id}"
        }',
        'message' => '{
          "text": "{text}"
        }'
      ),
     $accesstoken
    );
  } catch(FacebookExceptionsFacebookResponseException $e) {
    echo 'Graph returned an error: ' . $e->getMessage();
    exit;
  } catch(FacebookExceptionsFacebookSDKException $e) {
    echo 'Facebook SDK returned an error: ' . $e->getMessage();
    exit;
  }
  $graphNode = $response->getGraphNode();  
  }

so the user will infinitely recive the same message without stopping
<br>

i tried the solution here
https://stackoverflow.com/questions/39377533/infinite-loop-in-a-webhook
<br>

anyone can help me with this please to make it run just once?
thank you

This is probably not the answer you're looking for, but i've struggled with this same problem while developing a chatbot of my own. There is a combination of 2 solutions that fixed this issue:

Solution 1: If there is no input, or no message text and payload, the code exits. Here is an excerpt from my code:

$input = json_decode(file_get_contents('php://input'), true);
if(empty($input))
	exit();

$messageText = $input['entry'][0]['messaging'][0]['message']['text'];
$messagePayload = $input['entry'][0]['messaging'][0]['postback']['payload'];

if(empty($messageText) && empty($messagePayload)) {
	exit();
}

This was necessary because the chatbot just seemed to keep spamming my entry-point with empty requests over and over again. However...

Solution 2: I saved all message id-s in the database, and exit out if one is already being processed. This was necessary because I kept receiving certain messages 2 or 3 times in the API, and I had to avoid answering the same message twice. Here is a short excerpt:

$mid = $input['entry'][0]['messaging'][0]['message']['mid'];
$received = $this->user->isReceived($mid); // To avoid reacting to the same message twice
if($received) {
	exit();
} else {
    $this->user->logMsg($mid);
}

In the isReceived function, I check if the custom table of message id-s already contains this message. In the logMsg function, I store the id. They are a bit more complicated and framework-dependant however, so you will have to write these functions on your own, as you see them fit for your project.

Good luck, I hope someone chimes in with a better solution.

try {
  // Returns a `FacebookFacebookResponse` object
  $response = $fb->get(
    '/{to_id}?fields=conversations{messages{message}}',
    $accesstoken
  );
} catch(FacebookExceptionsFacebookResponseException $e) {
  echo 'Graph returned an error: ' . $e->getMessage();
  exit;
} catch(FacebookExceptionsFacebookSDKException $e) {
  echo 'Facebook SDK returned an error: ' . $e->getMessage();
  exit;
}
$idchk = $response->getGraphNode();
$datachk = json_decode($idchk);
if (($data->object == "page")&&(strpos($idchk,'hey')=="")) {   
  try {
    $response = $fb->post(
      '/me/messages',
      array (
        'recipient' => '{
          "id": "{to_id}"
        }',
        'message' => '{
          "text": "hey"
        }'
      ),
     $accesstoken
    );
    
    exit;
  } catch(FacebookExceptionsFacebookResponseException $e) {
    echo 'Graph returned an error: ' . $e->getMessage();
    
    exit;

  } catch(FacebookExceptionsFacebookSDKException $e) {

    echo 'Facebook SDK returned an error: ' . $e->getMessage();

}}

    exit;