PHP Source Code : Complete Facebook Chat Bot using PHP

Facebook Page has now become a vital part for any business. With increasing dependency on Facebook for promoting products or services, Facebook Messenger Chat Bot can prove to be a new tool to enhance your business to the targeted audience.

Source Code PHP

<?php


$access_token = '{ACCESS_TOKEN_HERE}';

$verify_token = '{VERIFY_TOKEN_HERE}';

$hub_verify_token = null;

if(isset($_REQUEST['hub_mode']) && $_REQUEST['hub_mode']=='subscribe'){
  $challenge = $_REQUEST['hub_challenge'];
  $hub_verify_token = $_REQUEST['hub_verify_token'];
  if($hub_verify_token===$verify_token){
    header('HTTP/1.1 200 OK');
    echo $challenge;
    die;
  }
}

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

$sender = $input['entry'][0]['messaging'][0]['sender']['id'];
$message = isset($input['entry'][0]['messaging'][0]['message']['text'])? $input['entry'][0]['messaging'][0]['message']['text']:'';

if($message){

  //you can change your logic here to reply what you want

  if($message=='hi'){ //if user sends hi we will reply like this
    $message_to_reply = 'Hello !!! How can I help you ?';
  }else{
    $message_to_reply = "This is the message to send back to the user";
  }

  $url = "https://graph.facebook.com/v2.6/me/messages?access_token=".$access_token;

  $jsonData = '{
          "recipient:{
            "id":"'.$sendere.'"
          },
          "message":{
            "text":"'.$message_to_reply.'"
          }
        }';

  $ch = curl_init($url);
  curl_setopt($ch,CURLOPT_POST,1);
  curl_setopt($ch,CURLOPT_POSTFIELDS,$jsonData);
  curl_setopt($ch, CURLOPT_HTTPHEADER, array('Content-Type: application/json'));
  curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
  $result = curl_exec($ch);
  curl_close($ch);
}

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