Index: src/applications/differential/conduit/ConduitAPI_differential_createcomment_Method.php
===================================================================
--- src/applications/differential/conduit/ConduitAPI_differential_createcomment_Method.php
+++ src/applications/differential/conduit/ConduitAPI_differential_createcomment_Method.php
@@ -7,7 +7,7 @@
   extends ConduitAPIMethod {
 
   public function getMethodDescription() {
-    return "Add a comment to a Differential revision.";
+    return pht("Add a comment to a Differential revision.");
   }
 
   public function defineParamTypes() {
@@ -31,32 +31,55 @@
   }
 
   protected function execute(ConduitAPIRequest $request) {
+    $viewer = $request->getUser();
+
     $revision = id(new DifferentialRevisionQuery())
-      ->setViewer($request->getUser())
+      ->setViewer($viewer)
       ->withIDs(array($request->getValue('revision_id')))
+      ->needReviewerStatus(true)
       ->executeOne();
     if (!$revision) {
       throw new ConduitException('ERR_BAD_REVISION');
     }
 
-    $content_source = PhabricatorContentSource::newForSource(
-      PhabricatorContentSource::SOURCE_CONDUIT,
-      array());
+    $xactions = array();
 
     $action = $request->getValue('action');
-    if (!$action) {
-      $action = 'none';
+    if ($action && ($action != 'comment')) {
+      $xactions[] = id(new DifferentialTransaction())
+        ->setTransactionType(DifferentialTransaction::TYPE_ACTION)
+        ->setNewValue($action);
+    }
+
+    $content = $request->getValue('message');
+    if (strlen($content)) {
+      $xactions[] = id(new DifferentialTransaction())
+        ->setTransactionType(PhabricatorTransactions::TYPE_COMMENT)
+        ->attachComment(
+          id(new DifferentialTransactionComment())
+            ->setContent($content));
     }
 
-    $editor = new DifferentialCommentEditor(
-      $revision,
-      $action);
-    $editor->setActor($request->getUser());
-    $editor->setContentSource($content_source);
-    $editor->setMessage($request->getValue('message'));
-    $editor->setNoEmail($request->getValue('silent'));
-    $editor->setAttachInlineComments($request->getValue('attach_inlines'));
-    $editor->save();
+    if ($request->getValue('attach_inlines')) {
+      $type_inline = DifferentialTransaction::TYPE_INLINE;
+      $inlines = DifferentialTransactionQuery::loadUnsubmittedInlineComments(
+        $viewer,
+        $revision);
+      foreach ($inlines as $inline) {
+        $xactions[] = id(new DifferentialTransaction())
+          ->setTransactionType($type_inline)
+          ->attachComment($inline);
+      }
+    }
+
+    $editor = id(new DifferentialTransactionEditor())
+      ->setActor($viewer)
+      ->setDisableEmail($request->getValue('silent'))
+      ->setContentSourceFromConduitRequest($request)
+      ->setContinueOnNoEffect(true)
+      ->setContinueOnMissingFields(true);
+
+    $editor->applyTransactions($revision, $xactions);
 
     return array(
       'revisionid'  => $revision->getID(),
Index: src/applications/differential/controller/DifferentialCommentSaveController.php
===================================================================
--- src/applications/differential/controller/DifferentialCommentSaveController.php
+++ src/applications/differential/controller/DifferentialCommentSaveController.php
@@ -87,17 +87,9 @@
         ->setNewValue(array('+' => $reviewer_edges));
     }
 
-    $inline_phids = $this->loadUnsubmittedInlinePHIDs($revision);
-    if ($inline_phids) {
-      $inlines = id(new PhabricatorApplicationTransactionCommentQuery())
-        ->setTemplate(new DifferentialTransactionComment())
-        ->setViewer($viewer)
-        ->withPHIDs($inline_phids)
-        ->execute();
-    } else {
-      $inlines = array();
-    }
-
+    $inlines = DifferentialTransactionQuery::loadUnsubmittedInlineComments(
+      $viewer,
+      $revision);
     foreach ($inlines as $inline) {
       $xactions[] = id(new DifferentialTransaction())
         ->setTransactionType($type_inline)
@@ -153,30 +145,4 @@
       ->setURI('/D'.$revision->getID());
   }
 
-
-  private function loadUnsubmittedInlinePHIDs(DifferentialRevision $revision) {
-    $viewer = $this->getRequest()->getUser();
-
-    // TODO: This probably needs to move somewhere more central as we move
-    // away from DifferentialInlineCommentQuery, but
-    // PhabricatorApplicationTransactionCommentQuery is currently `final` and
-    // I'm not yet decided on how to approach that. For now, just get the PHIDs
-    // and then execute a PHID-based query through the standard stack.
-
-    $table = new DifferentialTransactionComment();
-    $conn_r = $table->establishConnection('r');
-
-    $phids = queryfx_all(
-      $conn_r,
-      'SELECT phid FROM %T
-        WHERE revisionPHID = %s
-          AND authorPHID = %s
-          AND transactionPHID IS NULL',
-      $table->getTableName(),
-      $revision->getPHID(),
-      $viewer->getPHID());
-
-    return ipull($phids, 'phid');
-  }
-
 }
Index: src/applications/differential/query/DifferentialTransactionQuery.php
===================================================================
--- src/applications/differential/query/DifferentialTransactionQuery.php
+++ src/applications/differential/query/DifferentialTransactionQuery.php
@@ -7,4 +7,39 @@
     return new DifferentialTransaction();
   }
 
+  public static function loadUnsubmittedInlineComments(
+    PhabricatorUser $viewer,
+    DifferentialRevision $revision) {
+
+    // TODO: This probably needs to move somewhere more central as we move
+    // away from DifferentialInlineCommentQuery, but
+    // PhabricatorApplicationTransactionCommentQuery is currently `final` and
+    // I'm not yet decided on how to approach that. For now, just get the PHIDs
+    // and then execute a PHID-based query through the standard stack.
+
+    $table = new DifferentialTransactionComment();
+    $conn_r = $table->establishConnection('r');
+
+    $phids = queryfx_all(
+      $conn_r,
+      'SELECT phid FROM %T
+        WHERE revisionPHID = %s
+          AND authorPHID = %s
+          AND transactionPHID IS NULL',
+      $table->getTableName(),
+      $revision->getPHID(),
+      $viewer->getPHID());
+
+    $phids = ipull($phids, 'phid');
+    if (!$phids) {
+      return array();
+    }
+
+    return id(new PhabricatorApplicationTransactionCommentQuery())
+      ->setTemplate(new DifferentialTransactionComment())
+      ->setViewer($viewer)
+      ->withPHIDs($phids)
+      ->execute();
+  }
+
 }
Index: src/applications/transactions/editor/PhabricatorApplicationTransactionEditor.php
===================================================================
--- src/applications/transactions/editor/PhabricatorApplicationTransactionEditor.php
+++ src/applications/transactions/editor/PhabricatorApplicationTransactionEditor.php
@@ -25,6 +25,7 @@
   private $isPreview;
   private $isHeraldEditor;
   private $actingAsPHID;
+  private $disableEmail;
 
   public function setActingAsPHID($acting_as_phid) {
     $this->actingAsPHID = $acting_as_phid;
@@ -128,6 +129,21 @@
     return $this->isHeraldEditor;
   }
 
+  /**
+   * Prevent this editor from generating email when applying transactions.
+   *
+   * @param bool  True to disable email.
+   * @return this
+   */
+  public function setDisableEmail($disable_email) {
+    $this->disableEmail = $disable_email;
+    return $this;
+  }
+
+  public function getDisableEmail() {
+    return $this->disableEmail;
+  }
+
   public function getTransactionTypes() {
     $types = array();
 
@@ -682,8 +698,10 @@
     $this->loadHandles($xactions);
 
     $mail = null;
-    if ($this->shouldSendMail($object, $xactions)) {
-      $mail = $this->sendMail($object, $xactions);
+    if (!$this->getDisableEmail()) {
+      if ($this->shouldSendMail($object, $xactions)) {
+        $mail = $this->sendMail($object, $xactions);
+      }
     }
 
     if ($this->supportsSearch()) {