--- /dev/null
+<?php
+
+namespace Drupal\outside_in;
+
+/**
+ * Provides an interface for managing information related to Outside-In.
+ */
+interface OutsideInManagerInterface {
+
+ /**
+ * Determines if the Settings Tray logic should be run on the current page.
+ *
+ * @return bool
+ * TRUE if the Settings Tray logic should be run.
+ */
+ public function isApplicable();
+
+}