Index: src/applications/subscriptions/events/PhabricatorSubscriptionsUIEventListener.php
===================================================================
--- src/applications/subscriptions/events/PhabricatorSubscriptionsUIEventListener.php
+++ src/applications/subscriptions/events/PhabricatorSubscriptionsUIEventListener.php
@@ -5,6 +5,7 @@
 
   public function register() {
     $this->listen(PhabricatorEventType::TYPE_UI_DIDRENDERACTIONS);
+    $this->listen(PhabricatorEventType::TYPE_UI_DIDRENDERHOVERCARD);
   }
 
   public function handleEvent(PhutilEvent $event) {
@@ -12,6 +13,9 @@
       case PhabricatorEventType::TYPE_UI_DIDRENDERACTIONS:
         $this->handleActionEvent($event);
       break;
+      case PhabricatorEventType::TYPE_UI_DIDRENDERHOVERCARD:
+        $this->handleHovercardEvent($event);
+      break;
     }
   }
 
@@ -41,16 +45,7 @@
     } else {
       $subscribed = false;
       if ($user->isLoggedIn()) {
-        $src_phid = $object->getPHID();
-        $dst_phid = $user->getPHID();
-        $edge_type = PhabricatorEdgeConfig::TYPE_OBJECT_HAS_SUBSCRIBER;
-
-        $edges = id(new PhabricatorEdgeQuery())
-          ->withSourcePHIDs(array($src_phid))
-          ->withEdgeTypes(array($edge_type))
-          ->withDestinationPHIDs(array($user->getPHID()))
-          ->execute();
-        $subscribed = isset($edges[$src_phid][$edge_type][$dst_phid]);
+        $subscribed = $this->fetchStatusFromEdge($object, $user);
       }
 
       if ($subscribed) {
@@ -81,4 +76,61 @@
     $event->setValue('actions', $actions);
   }
 
+  private function handleHovercardEvent(PhutilEvent $event) {
+    $user = $event->getUser();
+    $object = $event->getValue('object');
+    $hc = $event->getValue('hovercard');
+
+    if (!$object || !$object->getPHID()) {
+      // No object, or the object has no PHID yet. No way to subscribe.
+      return;
+    }
+
+    if (!($object instanceof PhabricatorSubscribableInterface)) {
+      // This object isn't subscribable.
+      return;
+    }
+
+    if (!$user->isLoggedIn()) {
+      // I don't think we should unnecessarily increase the height of the
+      // hovercard for non-logged in users. They should just feel the sleekness
+      // of this beauty and get hooked up to pay my subscriptions instead :D.
+      return;
+    }
+
+    if ($object->isAutomaticallySubscribed($user->getPHID())) {
+      $hc->addAction(pht('Uhh...'), null);
+    } else {
+      $subscribed = $this->fetchStatusFromEdge($object, $user);
+      $hc->setUser($user);
+
+      // Workflow no work? You just get a page reload
+      if ($subscribed) {
+        $hc->addAction(pht('Unsubscribe'),
+          '/subscriptions/delete/'.$object->getPHID().'/',
+          true,
+          true);
+      } else {
+        $hc->addAction(pht('Subscribe'),
+          '/subscriptions/add/'.$object->getPHID().'/',
+          true,
+          true);
+      }
+    }
+    $event->setValue('hovercard', $hc);
+  }
+
+  private function fetchStatusFromEdge($object, $user) {
+      $src_phid = $object->getPHID();
+      $dst_phid = $user->getPHID();
+      $edge_type = PhabricatorEdgeConfig::TYPE_OBJECT_HAS_SUBSCRIBER;
+
+      $edges = id(new PhabricatorEdgeQuery())
+        ->withSourcePHIDs(array($src_phid))
+        ->withEdgeTypes(array($edge_type))
+        ->withDestinationPHIDs(array($dst_phid))
+        ->execute();
+      return isset($edges[$src_phid][$edge_type][$dst_phid]);
+  }
+
 }
Index: src/view/widget/hovercard/PhabricatorHovercardView.php
===================================================================
--- src/view/widget/hovercard/PhabricatorHovercardView.php
+++ src/view/widget/hovercard/PhabricatorHovercardView.php
@@ -42,11 +42,12 @@
     return $this;
   }
 
-  public function addAction($label, $uri, $workflow = false) {
+  public function addAction($label, $uri, $workflow = false, $form = false) {
     $this->actions[] = array(
       'label'    => $label,
       'uri'      => $uri,
       'workflow' => $workflow,
+      'form'     => $form,
     );
     return $this;
   }
@@ -67,6 +68,7 @@
     }
 
     $handle = $this->handle;
+    $user = $this->getUser();
 
     require_celerity_resource("phabricator-hovercard-view-css");
 
@@ -131,7 +133,23 @@
         'href'  => $action['uri'],
       );
 
-      if ($action['workflow']) {
+      if ($action['form']) {
+        if (!$user) {
+          throw new Exception(
+            'Call setUser() when rendering an action as a form.');
+        }
+        $buttons[] = phabricator_form($user,
+          array(
+            'action' => $action['uri'],
+            'method' => 'POST',
+            'sigil' => $action['workflow'] ? 'workflow' : null,
+          ),
+          phutil_tag('button',
+            array(
+              'class' => 'button grey',
+            ),
+            $action['label']));
+      } else if ($action['workflow']) {
         $options['sigil'] = 'workflow';
         $buttons[] = javelin_tag(
           'a',