php - Simple slim session manager not read session in a different function -

i using following slim session manager(https://github.com/bryanjhv/slim-session). have separate functions login, logout , user_data.

$app->post("/login", function() use ($app)         {              $input = $app->request()->getbody();            $input = json_decode($input);             try              {                  if ($input->username && $input->password)                      {                         $user = model::factory('users')->where("username",$input->username)->where("password",md5($input->password))->find_one();                     $session = new \slimsession\helper;                      //set session                     $session->set('userid', $user->id);                           $status = 'success';                         $message = 'logged in successfully.';                     }                  else                         {                             $status = 'danger';                             $message = 'could not log in. please try again.';                         }              }             catch (exception $e)                      {                         $status = 'danger';                         $message = $e->getmessage();                     }             $response = array(                 'status' => $status,                 'message' => $message,             );             $app->response()->header("content-type", "application/json");             echo json_encode($response);          });            $app->post("/logout",function() use ($app)         {              try {                         $session = new \slimsession\helper;                     $session::destroy();                          $status = 'success';                         $message = 'you have been logged out successfully';                     }               catch (exception $e)                      {                         $status = 'danger';                         $message = $e->getmessage();                     }             $response = array(                 'status' => $status,                 'message' => $message             );              $app->response()->header("content-type", "application/json");             echo json_encode($response);          });   $app->get("/user_data", function() use ($app)         {              try               {                     $session = new \slimsession\helper;                     //get session                     $userid = $session->get('userid');                   $_session['userid'] = $userid;                 if ($_session['userid'])                     {                         $users = model::factory('users')->where('id',$_session['userid'])->find_one();                         $response = array(              'id'=>$users->id,                             'username'=>$users->username,                             'email'=>$users->email,                             'phone_number'=>$users->phone_number,                             'password'=>$users->password,                             'type'=>$users->type,                             'credits'=>$users->credits,                             'profile_picture'=>$users->profile_picture,                             );                       }                 else                 {                     $status = "danger";                     $message = 'you need logged in that.';                      $response = array(                     'status' => $status,                     'message' => $message                     );                 }               }              catch (exception $e)                  {                     $status = "danger";                     $message = $e->getmessage();                      $response = array(                     'status' => $status,                     'message' => $message                     );                 }               $app->response()->header("content-type", "application/json");             echo json_encode($response);          });  

the problem having when user logs in set session variable in /login function. when session variable set in login function isn't being retrieved in /user_data function.

anyone knows whats going on?

have started session session_start() ?

correct logic check session follows:

if (isset($_session['userid'])) {     // session exists     // further work }