diff --git a/conf/default.conf.php b/conf/default.conf.php
index 0cb3f9db72..485c0a4026 100644
--- a/conf/default.conf.php
+++ b/conf/default.conf.php
@@ -997,6 +997,17 @@ return array(
   // interact with the revisions.
   'differential.anonymous-access' => false,
 
+  // If you set this to true, revision author email address information will
+  // be exposed in Conduit. This is useful for Arcanist.
+  //
+  // For example, consider the "arc patch DX" workflow which needs to ask
+  // Differential for the revision DX. This data often should contain
+  // the author's email address, eg "George Washington
+  // <gwashinton@example.com>" when DX is a git or mercurial revision. If this
+  // option is false, Differential defaults to the best it can, something like
+  // "George Washington" or "gwashington".
+  'differential.expose-emails-prudently' => false,
+
   // List of file regexps that should be treated as if they are generated by
   // an automatic process, and thus get hidden by default in differential.
   'differential.generated-paths' => array(
diff --git a/src/applications/conduit/method/differential/ConduitAPI_differential_getdiff_Method.php b/src/applications/conduit/method/differential/ConduitAPI_differential_getdiff_Method.php
index 85b59c72b6..5f2719691d 100644
--- a/src/applications/conduit/method/differential/ConduitAPI_differential_getdiff_Method.php
+++ b/src/applications/conduit/method/differential/ConduitAPI_differential_getdiff_Method.php
@@ -64,7 +64,7 @@ final class ConduitAPI_differential_getdiff_Method extends ConduitAPIMethod {
     $basic_dict = $diff->getDiffDict();
 
     // for conduit calls, the basic dict is not enough
-    // we also need to include the arcanist project
+    // we also need to include the arcanist project and author information
     $project = $diff->loadArcanistProject();
     if ($project) {
       $project_name = $project->getName();
@@ -72,6 +72,7 @@ final class ConduitAPI_differential_getdiff_Method extends ConduitAPIMethod {
       $project_name = null;
     }
     $basic_dict['projectName'] = $project_name;
+    $basic_dict['author'] = $diff->loadAuthorInformation();
 
     return $basic_dict;
   }
diff --git a/src/applications/differential/storage/DifferentialDiff.php b/src/applications/differential/storage/DifferentialDiff.php
index c8f09d0463..38f64733c3 100644
--- a/src/applications/differential/storage/DifferentialDiff.php
+++ b/src/applications/differential/storage/DifferentialDiff.php
@@ -312,4 +312,52 @@ final class DifferentialDiff extends DifferentialDAO {
 
     return $dict;
   }
+
+  /**
+   * Figures out the right author information for a given diff based on the
+   * repository and Phabricator configuration settings.
+   *
+   * Git is particularly finicky as it requires author information to be in
+   * the format "George Washington <gwashington@example.com>" to
+   * consistently work. If the Phabricator instance isn't configured to
+   * expose emails prudently, then we are unable to get any author information
+   * for git.
+   */
+  public function loadAuthorInformation() {
+    $author = id(new PhabricatorUser())
+      ->loadOneWhere('phid = %s', $this->getAuthorPHID());
+
+    $use_emails =
+      PhabricatorEnv::getEnvConfig('differential.expose-emails-prudently',
+                                   false);
+
+    switch ($this->getSourceControlSystem()) {
+      case PhabricatorRepositoryType::REPOSITORY_TYPE_GIT:
+        if (!$use_emails) {
+          $author_info = '';
+        } else {
+          $author_info = $this->getFullAuthorInfo($author);
+        }
+        break;
+      case PhabricatorRepositoryType::REPOSITORY_TYPE_MERCURIAL:
+        if (!$use_emails) {
+          $author_info = $author->getUsername();
+        } else {
+          $author_info = $this->getFullAuthorInfo($author);
+        }
+       break;
+      case PhabricatorRepositoryType::REPOSITORY_TYPE_SVN:
+      default:
+        $author_info = $author->getUsername();
+        break;
+    }
+
+    return $author_info;
+  }
+
+  private function getFullAuthorInfo(PhabricatorUser $author) {
+    return sprintf('%s <%s>',
+                   $author->getRealName(),
+                   $author->loadPrimaryEmailAddress());
+  }
 }