Custom Header not available in Laravel $request object

I have a web application, where I am authenticating based on my custom token sent in headers as 'API_TOKEN'. I am not sure about what is happening, after all the code digging I did in source (laravel)

Here is my middleware

protected $AUTH_HEADER = 'API_TOKEN';
protected $_RESPONSE = array('status' => false, 'message' => '', 'data' => array());

public function handle($request, Closure $next, $guard = null)
{
  $response = $this->_RESPONSE;
  if($request->hasHeader($this->AUTH_HEADER)){
    $api_token = $request->header($this->AUTH_HEADER);
    try{
      $request->user = \App\User::where(['api_token' => $api_token])->firstOrFail();
      Auth::login($request->user);
      $response = $next($request);
    }catch(\Exception $exception){
      $response['status'] = false;
      $response['message'] = 'Invalid Token.';
    }
  }else{
    $response['status'] = false;
    $response['message'] = 'Unauthorized Request.';
  }

  // Lines ONLY I used for cross verification of availability of my header
  // $response['data'] = getallheaders();
  // $response['data'] = $_SERVER;
  return $response;
}

Here is a screenshot of my POST request, api.easyinventory.com is a custom virtual host which maps to my app

My routes are placed right as follow in api.php which by default will placed below route group under api prefix

Route::group(['prefix' => 'product'], function(){
    Route::get('read', 'API\ProductController@read');
}

Coming to the problem, if I call getallheaders(), I can see my custom header as shown below

But in $request, I am not able to get it. I will be grateful for any lead on this issue.

My effort includes tracking down where these headers are actually SET in $request object, I checked ServerBag.php in Symfony source code

Symfony ServerBag Class Method - getHeaders.

If you look at this function getHeaders. It only adds selective headers in headers array, either with Content as starting string or starting with HTTP_. I tried passing my own header like HTTP_API_TOKEN but success :-(

via Farooq Khan