diff --git a/graphapi.api.php b/graphapi.api.php
index c410333..1ceab6f 100644
--- a/graphapi.api.php
+++ b/graphapi.api.php
@@ -43,9 +43,34 @@ function hook_graphapi_settings_form() {
   // tbd
 }
 
-// @see http://drupal.org/node/1513198
+/**
+ * Declares settings that should be exportable in Views.
+ *
+ * The settings declared here will be included in the option_definition()
+ * method, as implemented in the Graph API style plugin.
+ * @return array
+ *   An associative array corresponding to the (exportable) settings provided by
+ *   your graph engine. Each entry is an associative array that at least has
+ *   the entry 'default' describing the default value exported if no setting to
+ *   export is found. (Any other entries accepted by option_definition() is fine
+ *   to add too.)
+ *
+ * @see hook_graphapi_settings_form()
+ * @see views_plugin_style::option_definition()
+ */
 function hook_graphapi_default_settings() {
-  // tbd
+  // Settings used by the first graph engine.
+  $settings['my_first_engine'] = array(
+    'setting 1' => array('default' => NULL),
+    'setting 2' => array('default' => 1),
+    'setting 3' => array('default' => t('Some string')),
+  );
+  // Settings used by the second graph engine.
+  $settings['my_second_engine'] = array(
+    'setting 1' => array('default' => 1),
+    'setting 2' => array('default' => NULL),
+  );
+  return $settings;
 }
 
 /**
diff --git a/views/plugins/views_plugin_style_graphapi.inc b/views/plugins/views_plugin_style_graphapi.inc
index 45be505..6442f6b 100644
--- a/views/plugins/views_plugin_style_graphapi.inc
+++ b/views/plugins/views_plugin_style_graphapi.inc
@@ -46,10 +46,18 @@ class views_plugin_style_graphapi extends views_plugin_style {
    */
   function option_definition() {
     $options = parent::option_definition();
+
+    // Get the settings we need to export provided by Graph API.
     $options['engine'] = array('default' => 'graphapi');
     foreach ($this->graph_fields as $id => $data) {
-      $options['mapping'][$id] = array('default' => NULL);
+      foreach ($data as $key => $value) {
+        $options['mapping'][$id][$key] = array('default' => NULL);
+      }
     }
+
+    // Add settings provided by plugin engines.
+    $options += module_invoke_all('graphapi_default_settings');
+
     return $options;
   }