diff --git a/src/includes/api/ListsController.php b/src/includes/api/ListsController.php
index 3aac2b1..b76cd99 100644
--- a/src/includes/api/ListsController.php
+++ b/src/includes/api/ListsController.php
@@ -62,7 +62,9 @@ class ListsController extends ApiController {
         $id = $db->lastInsertId();
         $t['total'] = 1;
         $r = $db->sqa("SELECT * FROM {$db->prefix}lists WHERE id=$id");
-        $t['list'][] = $this->prepareList($r, true);
+        $oo = $this->prepareList($r, true);
+        MTTNotificationCenter::postNotification(MTTNotification::didCreateList, $oo);
+        $t['list'][] = $oo;
         return $t;
     }
 
diff --git a/src/includes/api/TasksController.php b/src/includes/api/TasksController.php
index d7f038d..0702529 100644
--- a/src/includes/api/TasksController.php
+++ b/src/includes/api/TasksController.php
@@ -250,7 +250,9 @@ class TasksController extends ApiController {
         }
         $db->ex("COMMIT");
         $r = $db->sqa("SELECT * FROM {$db->prefix}todolist WHERE id=$id");
-        $t['list'][] = $this->prepareTaskRow($r);
+        $oo = $this->prepareTaskRow($r);
+        MTTNotificationCenter::postNotification(MTTNotification::didCreateTask, $oo);
+        $t['list'][] = $oo;
         $t['total'] = 1;
         return $t;
     }
@@ -288,7 +290,9 @@ class TasksController extends ApiController {
         }
         $db->ex("COMMIT");
         $r = $db->sqa("SELECT * FROM {$db->prefix}todolist WHERE id=$id");
-        $t['list'][] = $this->prepareTaskRow($r);
+        $oo = $this->prepareTaskRow($r);
+        MTTNotificationCenter::postNotification(MTTNotification::didCreateTask, $oo);
+        $t['list'][] = $oo;
         $t['total'] = 1;
         return $t;
     }
diff --git a/src/includes/notifications.php b/src/includes/notifications.php
new file mode 100644
index 0000000..9f17547
--- /dev/null
+++ b/src/includes/notifications.php
@@ -0,0 +1,86 @@
+<?php declare(strict_types=1);
+
+class MTTNotificationCenter
+{
+    /**
+     * @var array<string, MTTNotificationObserverInterface[]>
+     */
+    private static $observers = [];
+
+    /**
+     * @var array<array>
+     */
+    private static $notificationStore = [];
+
+    /**
+     * @param string $notification
+     * @param MTTNotificationObserverInterface $observer
+     * @return void
+     */
+    public static function addObserverForNotification(string $notification, MTTNotificationObserverInterface $observer)
+    {
+        if (!isset(self::$observers[$notification])) {
+            self::$observers[$notification] = [];
+        }
+        self::$observers[$notification][] = $observer;
+    }
+
+    /**
+     * @param string[] $notifications
+     * @param MTTNotificationObserverInterface $observer
+     * @return void
+     */
+    public static function addObserverForNotifications(array $notifications, MTTNotificationObserverInterface $observer)
+    {
+        foreach ($notifications as $notification) {
+            self::addObserverForNotification($notification, $observer);
+        }
+    }
+
+
+    public static function postNotification(string $notification, $object)
+    {
+        self::$notificationStore[] = [
+            'notification' => $notification,
+            'object' => $object
+        ];
+    }
+
+    /**
+     * Run this near exit()
+     * @return void
+     */
+    public static function notifyDelayedObservers()
+    {
+        if (count(self::$notificationStore) == 0) {
+            return; // No notifications
+        }
+        if (session_status() == PHP_SESSION_ACTIVE) {
+            session_write_close(); // Close active session
+        }
+        if (function_exists('fastcgi_finish_request')) {
+            fastcgi_finish_request();
+        }
+        foreach (self::$notificationStore as $notificationItem) {
+            $notification = $notificationItem['notification'];
+            $object = $notificationItem['object'];
+            $observers = self::$observers[$notification] ?? [];
+            foreach ($observers as $observer) {
+                $observer->notification($notification, $object);
+            }
+        }
+    }
+}
+
+interface MTTNotificationObserverInterface
+{
+    function notification(string $notification, $object);
+}
+
+// Enum
+abstract class MTTNotification
+{
+    const didCreateTask = 'didCreateTask';
+    const didCreateList = 'didCreateList';
+}
+
diff --git a/src/init.php b/src/init.php
index 82a3523..662a69d 100644
--- a/src/init.php
+++ b/src/init.php
@@ -25,10 +25,11 @@ else {
 }
 
 require_once(MTTINC. 'common.php');
+require_once(MTTINC. 'version.php');
 require_once(MTTINC. 'class.dbconnection.php');
 require_once(MTTINC. 'class.dbcore.php');
 require_once(MTTINC. 'class.config.php');
-require_once(MTTINC. 'version.php');
+require_once(MTTINC. 'notifications.php');
 
 requireConfig();
 configureDbConnection();
@@ -322,6 +323,7 @@ function jsonExit($data)
     header('Pragma: no-cache'); // for old HTTP/1.0 intermediate caches
     header_remove('Expires');
     echo json_encode($data, JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES);
+    MTTNotificationCenter::notifyDelayedObservers();
     exit;
 }