diff --git a/src/Controller/APIController.php b/src/Controller/APIController.php
index d0099e73..364215c1 100644
--- a/src/Controller/APIController.php
+++ b/src/Controller/APIController.php
@@ -53,7 +53,7 @@ use DateTime;
 use Exception;
 
 // mobile API
-class APIController extends Controller
+class APIController extends Controller implements LoggedController
 {
     protected $session;
 
diff --git a/src/Controller/LoggedController.php b/src/Controller/LoggedController.php
new file mode 100644
index 00000000..00e7c02a
--- /dev/null
+++ b/src/Controller/LoggedController.php
@@ -0,0 +1,7 @@
+<?php
+
+namespace App\Controller;
+
+interface LoggedController
+{
+}
diff --git a/src/EventSubscriber/LogSubscriber.php b/src/EventSubscriber/LogSubscriber.php
new file mode 100644
index 00000000..af227133
--- /dev/null
+++ b/src/EventSubscriber/LogSubscriber.php
@@ -0,0 +1,55 @@
+<?php
+
+namespace App\EventSubscriber;
+
+use App\Controller\LoggedController;
+use Symfony\Component\EventDispatcher\EventSubscriberInterface;
+use Symfony\Component\HttpKernel\Event\ControllerEvent;
+use Symfony\Component\HttpKernel\Event\ResponseEvent;
+use Symfony\Component\HttpKernel\Exception\AccessDeniedHttpException;
+use Symfony\Component\HttpKernel\KernelEvents;
+
+class LogSubscriber implements EventSubscriberInterface
+{
+    protected $allow;
+
+    public function __construct()
+    {
+        $this->allow = true;
+    }
+
+    public function onKernelController(ControllerEvent $event)
+    {
+        $controller = $event->getController();
+
+        // when a controller class defines multiple action methods, the controller
+        // is returned as [$controllerInstance, 'methodName']
+        if (is_array($controller))
+            $controller = $controller[0];
+
+        if ($controller instanceof LoggedController)
+            $this->allow = true;
+        else
+            $this->allow = false;
+    }
+
+    public function onKernelResponse(ResponseEvent $event)
+    {
+        if (!$this->allow)
+            return;
+
+        $resp = $event->getResponse();
+
+        $content = $resp->getContent();
+
+        error_log(print_r($content, true));
+    }
+
+    public static function getSubscribedEvents()
+    {
+        return [
+            KernelEvents::CONTROLLER => 'onKernelController',
+            KernelEvents::RESPONSE => 'onKernelResponse',
+        ];
+    }
+}