diff --git a/extensions/mentions/src/Handlers/PostMentionsMetadataUpdater.php b/extensions/mentions/src/Handlers/PostMentionsMetadataUpdater.php
index 5f36506c6..f74eb1658 100755
--- a/extensions/mentions/src/Handlers/PostMentionsMetadataUpdater.php
+++ b/extensions/mentions/src/Handlers/PostMentionsMetadataUpdater.php
@@ -1,7 +1,10 @@
 <?php namespace Flarum\Mentions\Handlers;
 
 use Flarum\Mentions\PostMentionsParser;
+use Flarum\Mentions\PostMentionedActivity;
 use Flarum\Mentions\PostMentionedNotification;
+use Flarum\Core\Activity\ActivitySyncer;
+use Flarum\Core\Notifications\NotificationSyncer;
 use Flarum\Core\Events\PostWasPosted;
 use Flarum\Core\Events\PostWasRevised;
 use Flarum\Core\Events\PostWasDeleted;
@@ -13,53 +16,77 @@ class PostMentionsMetadataUpdater
 {
     protected $parser;
 
-    protected $notifier;
+    protected $activity;
 
-    public function __construct(PostMentionsParser $parser, Notifier $notifier)
+    protected $notifications;
+
+    public function __construct(PostMentionsParser $parser, ActivitySyncer $activity, NotificationSyncer $notifications)
     {
         $this->parser = $parser;
-        $this->notifier = $notifier;
+        $this->activity = $activity;
+        $this->notifications = $notifications;
     }
 
     public function subscribe(Dispatcher $events)
     {
         $events->listen('Flarum\Core\Events\PostWasPosted', __CLASS__.'@whenPostWasPosted');
         $events->listen('Flarum\Core\Events\PostWasRevised', __CLASS__.'@whenPostWasRevised');
+        $events->listen('Flarum\Core\Events\PostWasHidden', __CLASS__.'@whenPostWasHidden');
+        $events->listen('Flarum\Core\Events\PostWasRestored', __CLASS__.'@whenPostWasRestored');
         $events->listen('Flarum\Core\Events\PostWasDeleted', __CLASS__.'@whenPostWasDeleted');
     }
 
     public function whenPostWasPosted(PostWasPosted $event)
     {
-        $reply = $event->post;
-
-        $mentioned = $this->syncMentions($reply);
-
-        // @todo convert this into a new event (PostWasMentioned) and send
-        // notification as a handler?
-        foreach ($mentioned as $post) {
-            if ($post->user->id !== $reply->user->id) {
-                $this->notifier->send(new PostMentionedNotification($post, $reply->user, $reply), [$post->user]);
-            }
-        }
+        $this->replyBecameVisible($event->post);
     }
 
     public function whenPostWasRevised(PostWasRevised $event)
     {
-        $this->syncMentions($event->post);
+        $this->replyBecameVisible($event->post);
+    }
+
+    public function whenPostWasHidden(PostWasHidden $event)
+    {
+        $this->replyBecameInvisible($event->post);
+    }
+
+    public function whenPostWasRestored(PostWasRestored $event)
+    {
+        $this->replyBecameVisible($event->post);
     }
 
     public function whenPostWasDeleted(PostWasDeleted $event)
     {
-        $event->post->mentionsPosts()->sync([]);
+        $this->replyBecameInvisible($event->post);
     }
 
-    protected function syncMentions(Post $reply)
+    protected function replyBecameVisible(Post $reply)
     {
         $matches = $this->parser->match($reply->content);
 
-        $mentioned = $reply->discussion->posts()->with('user')->whereIn('number', array_filter($matches['number']))->get();
-        $reply->mentionsPosts()->sync($mentioned->lists('id'));
+        $mentioned = $reply->discussion->posts()->with('user')->whereIn('number', array_filter($matches['number']))->get()->all();
 
-        return $mentioned;
+        $this->sync($reply, $mentioned);
+    }
+
+    protected function replyBecameInvisible(Post $reply)
+    {
+        $this->sync($reply, []);
+    }
+
+    protected function sync(Post $reply, array $mentioned)
+    {
+        $reply->mentionsPosts()->sync(array_pluck($mentioned, 'id'));
+
+        $mentioned = array_filter($mentioned, function ($post) use ($reply) {
+            return $post->user->id !== $reply->user->id;
+        });
+
+        foreach ($mentioned as $post) {
+            $this->activity->sync(new PostMentionedActivity($post, $reply), [$post->user]);
+
+            $this->notifications->sync(new PostMentionedNotification($post, $reply), [$post->user]);
+        }
     }
 }
diff --git a/extensions/mentions/src/Handlers/UserMentionsMetadataUpdater.php b/extensions/mentions/src/Handlers/UserMentionsMetadataUpdater.php
index f28f21615..2d2aeab30 100755
--- a/extensions/mentions/src/Handlers/UserMentionsMetadataUpdater.php
+++ b/extensions/mentions/src/Handlers/UserMentionsMetadataUpdater.php
@@ -1,66 +1,92 @@
 <?php namespace Flarum\Mentions\Handlers;
 
 use Flarum\Mentions\UserMentionsParser;
+use Flarum\Mentions\UserMentionedActivity;
 use Flarum\Mentions\UserMentionedNotification;
+use Flarum\Core\Activity\ActivitySyncer;
+use Flarum\Core\Notifications\NotificationSyncer;
 use Flarum\Core\Events\PostWasPosted;
 use Flarum\Core\Events\PostWasRevised;
 use Flarum\Core\Events\PostWasDeleted;
+use Flarum\Core\Events\PostWasHidden;
+use Flarum\Core\Events\PostWasRestored;
 use Flarum\Core\Models\Post;
 use Flarum\Core\Models\User;
-use Flarum\Core\Notifications\Notifier;
 use Illuminate\Contracts\Events\Dispatcher;
 
 class UserMentionsMetadataUpdater
 {
     protected $parser;
 
-    protected $notifier;
+    protected $activity;
 
-    public function __construct(UserMentionsParser $parser, Notifier $notifier)
+    protected $notifications;
+
+    public function __construct(UserMentionsParser $parser, ActivitySyncer $activity, NotificationSyncer $notifications)
     {
         $this->parser = $parser;
-        $this->notifier = $notifier;
+        $this->activity = $activity;
+        $this->notifications = $notifications;
     }
 
     public function subscribe(Dispatcher $events)
     {
         $events->listen('Flarum\Core\Events\PostWasPosted', __CLASS__.'@whenPostWasPosted');
         $events->listen('Flarum\Core\Events\PostWasRevised', __CLASS__.'@whenPostWasRevised');
+        $events->listen('Flarum\Core\Events\PostWasHidden', __CLASS__.'@whenPostWasHidden');
+        $events->listen('Flarum\Core\Events\PostWasRestored', __CLASS__.'@whenPostWasRestored');
         $events->listen('Flarum\Core\Events\PostWasDeleted', __CLASS__.'@whenPostWasDeleted');
     }
 
     public function whenPostWasPosted(PostWasPosted $event)
     {
-        $post = $event->post;
-
-        $mentioned = $this->syncMentions($post);
-
-        // @todo convert this into a new event (UserWasMentioned) and send
-        // notification as a handler?
-        foreach ($mentioned as $user) {
-            if ($user->id !== $post->user->id) {
-                $this->notifier->send(new UserMentionedNotification($post->user, $post), [$user]);
-            }
-        }
+        $this->postBecameVisible($event->post);
     }
 
     public function whenPostWasRevised(PostWasRevised $event)
     {
-        $this->syncMentions($event->post);
+        $this->postBecameVisible($event->post);
+    }
+
+    public function whenPostWasHidden(PostWasHidden $event)
+    {
+        $this->postBecameInvisible($event->post);
+    }
+
+    public function whenPostWasRestored(PostWasRestored $event)
+    {
+        $this->postBecameVisible($event->post);
     }
 
     public function whenPostWasDeleted(PostWasDeleted $event)
     {
-        $event->post->mentionsUsers()->sync([]);
+        $this->postBecameInvisible($event->post);
     }
 
-    public function syncMentions(Post $post)
+    protected function postBecameVisible(Post $post)
     {
         $matches = $this->parser->match($post->content);
 
-        $mentioned = User::whereIn('username', array_filter($matches['username']))->get();
-        $post->mentionsUsers()->sync($mentioned);
+        $mentioned = User::whereIn('username', array_filter($matches['username']))->get()->all();
 
-        return $mentioned;
+        $this->sync($post, $mentioned);
+    }
+
+    protected function postBecameInvisible(Post $post)
+    {
+        $this->sync($post, []);
+    }
+
+    protected function sync(Post $post, array $mentioned)
+    {
+        $post->mentionsUsers()->sync(array_pluck($mentioned, 'id'));
+
+        $mentioned = array_filter($mentioned, function ($user) use ($post) {
+            return $user->id !== $post->user->id;
+        });
+
+        $this->activity->sync(new UserMentionedActivity($post), $mentioned);
+
+        $this->notifications->sync(new UserMentionedNotification($post), $mentioned);
     }
 }
diff --git a/extensions/mentions/src/MentionsServiceProvider.php b/extensions/mentions/src/MentionsServiceProvider.php
index cd9b5ce8f..a2e07371c 100644
--- a/extensions/mentions/src/MentionsServiceProvider.php
+++ b/extensions/mentions/src/MentionsServiceProvider.php
@@ -8,6 +8,7 @@ use Flarum\Extend\SerializeRelationship;
 use Flarum\Extend\ApiInclude;
 use Flarum\Extend\Formatter;
 use Flarum\Extend\NotificationType;
+use Flarum\Extend\ActivityType;
 
 class MentionsServiceProvider extends ServiceProvider
 {
@@ -54,9 +55,15 @@ class MentionsServiceProvider extends ServiceProvider
 
             new Formatter('userMentions', 'Flarum\Mentions\UserMentionsFormatter'),
 
-            (new NotificationType('Flarum\Mentions\PostMentionedNotification'))->enableByDefault('alert'),
+            new ActivityType('Flarum\Mentions\PostMentionedActivity', 'Flarum\Api\Serializers\PostBasicSerializer'),
 
-            (new NotificationType('Flarum\Mentions\UserMentionedNotification'))->enableByDefault('alert')
+            new ActivityType('Flarum\Mentions\UserMentionedActivity', 'Flarum\Api\Serializers\PostBasicSerializer'),
+
+            (new NotificationType('Flarum\Mentions\PostMentionedNotification', 'Flarum\Api\Serializers\PostBasicSerializer'))
+                ->enableByDefault('alert'),
+
+            (new NotificationType('Flarum\Mentions\UserMentionedNotification', 'Flarum\Api\Serializers\PostBasicSerializer'))
+                ->enableByDefault('alert')
         );
     }
 }
diff --git a/extensions/mentions/src/PostMentionedActivity.php b/extensions/mentions/src/PostMentionedActivity.php
new file mode 100644
index 000000000..3da847c9f
--- /dev/null
+++ b/extensions/mentions/src/PostMentionedActivity.php
@@ -0,0 +1,37 @@
+<?php namespace Flarum\Mentions;
+
+use Flarum\Core\Models\Post;
+use Flarum\Core\Activity\ActivityAbstract;
+
+class PostMentionedActivity extends ActivityAbstract
+{
+    public $post;
+
+    public $reply;
+
+    public function __construct(Post $post, Post $reply)
+    {
+        $this->post = $post;
+        $this->reply = $reply;
+    }
+
+    public function getSubject()
+    {
+        return $this->reply;
+    }
+
+    public function getTime()
+    {
+        return $this->reply->time;
+    }
+
+    public static function getType()
+    {
+        return 'postMentioned';
+    }
+
+    public static function getSubjectModel()
+    {
+        return 'Flarum\Core\Models\Post';
+    }
+}
diff --git a/extensions/mentions/src/PostMentionedNotification.php b/extensions/mentions/src/PostMentionedNotification.php
index 1df460183..da6c7b256 100644
--- a/extensions/mentions/src/PostMentionedNotification.php
+++ b/extensions/mentions/src/PostMentionedNotification.php
@@ -1,25 +1,17 @@
 <?php namespace Flarum\Mentions;
 
-use Flarum\Core\Models\User;
 use Flarum\Core\Models\Post;
-use Flarum\Core\Notifications\Types\Notification;
-use Flarum\Core\Notifications\Types\AlertableNotification;
-use Flarum\Core\Notifications\Types\EmailableNotification;
+use Flarum\Core\Notifications\NotificationAbstract;
 
-class PostMentionedNotification extends Notification implements
-    AlertableNotification,
-    EmailableNotification
+class PostMentionedNotification extends NotificationAbstract
 {
     public $post;
 
-    public $sender;
-
     public $reply;
 
-    public function __construct(Post $post, User $sender, Post $reply)
+    public function __construct(Post $post, Post $reply)
     {
         $this->post = $post;
-        $this->sender = $sender;
         $this->reply = $reply;
     }
 
@@ -30,10 +22,10 @@ class PostMentionedNotification extends Notification implements
 
     public function getSender()
     {
-        return $this->sender;
+        return $this->reply->user;
     }
 
-    public function getAlertData()
+    public function getData()
     {
         return ['replyNumber' => $this->reply->number];
     }
@@ -45,7 +37,7 @@ class PostMentionedNotification extends Notification implements
 
     public function getEmailSubject()
     {
-        return "{$this->sender->username} replied to your post in {$this->post->discussion->title}";
+        return "{$this->reply->user->username} replied to your post in {$this->post->discussion->title}";
     }
 
     public static function getType()
@@ -57,4 +49,9 @@ class PostMentionedNotification extends Notification implements
     {
         return 'Flarum\Core\Models\Post';
     }
+
+    public static function isEmailable()
+    {
+        return true;
+    }
 }
diff --git a/extensions/mentions/src/UserMentionedActivity.php b/extensions/mentions/src/UserMentionedActivity.php
new file mode 100644
index 000000000..37c6b958b
--- /dev/null
+++ b/extensions/mentions/src/UserMentionedActivity.php
@@ -0,0 +1,34 @@
+<?php namespace Flarum\Mentions;
+
+use Flarum\Core\Models\Post;
+use Flarum\Core\Activity\ActivityAbstract;
+
+class UserMentionedActivity extends ActivityAbstract
+{
+    public $post;
+
+    public function __construct(Post $post)
+    {
+        $this->post = $post;
+    }
+
+    public function getSubject()
+    {
+        return $this->post;
+    }
+
+    public function getTime()
+    {
+        return $this->post->time;
+    }
+
+    public static function getType()
+    {
+        return 'userMentioned';
+    }
+
+    public static function getSubjectModel()
+    {
+        return 'Flarum\Core\Models\Post';
+    }
+}
diff --git a/extensions/mentions/src/UserMentionedNotification.php b/extensions/mentions/src/UserMentionedNotification.php
index 08c229239..7a3592d11 100644
--- a/extensions/mentions/src/UserMentionedNotification.php
+++ b/extensions/mentions/src/UserMentionedNotification.php
@@ -2,21 +2,14 @@
 
 use Flarum\Core\Models\User;
 use Flarum\Core\Models\Post;
-use Flarum\Core\Notifications\Types\Notification;
-use Flarum\Core\Notifications\Types\AlertableNotification;
-use Flarum\Core\Notifications\Types\EmailableNotification;
+use Flarum\Core\Notifications\NotificationAbstract;
 
-class UserMentionedNotification extends Notification implements
-    AlertableNotification,
-    EmailableNotification
+class UserMentionedNotification extends NotificationAbstract
 {
-    public $sender;
-
     public $post;
 
-    public function __construct(User $sender, Post $post)
+    public function __construct(Post $post)
     {
-        $this->sender = $sender;
         $this->post = $post;
     }
 
@@ -27,12 +20,7 @@ class UserMentionedNotification extends Notification implements
 
     public function getSender()
     {
-        return $this->sender;
-    }
-
-    public function getAlertData()
-    {
-        return null;
+        return $this->post->user;
     }
 
     public function getEmailView()
@@ -42,7 +30,7 @@ class UserMentionedNotification extends Notification implements
 
     public function getEmailSubject()
     {
-        return "{$this->sender->username} mentioned you in {$this->post->discussion->title}";
+        return "{$this->post->user->username} mentioned you in {$this->post->discussion->title}";
     }
 
     public static function getType()
@@ -54,4 +42,9 @@ class UserMentionedNotification extends Notification implements
     {
         return 'Flarum\Core\Models\Post';
     }
+
+    public static function isEmailable()
+    {
+        return true;
+    }
 }
diff --git a/extensions/mentions/views/emails/userMentioned.blade.php b/extensions/mentions/views/emails/userMentioned.blade.php
index e8ed2697d..ce450d076 100644
--- a/extensions/mentions/views/emails/userMentioned.blade.php
+++ b/extensions/mentions/views/emails/userMentioned.blade.php
@@ -1,6 +1,6 @@
 Hey {{ $user->username }}!
 
-{{ $notification->sender->username }} mentioned you in a post in {{ $notification->post->discussion->title }}.
+{{ $notification->post->user->username }} mentioned you in a post in {{ $notification->post->discussion->title }}.
 
 {{ \Flarum\Core::config('base_url') }}/d/{{ $notification->post->discussion_id }}/-/{{ $notification->post->number }}