diff --git a/server/src/main/java/org/opensearch/common/util/FeatureFlags.java b/server/src/main/java/org/opensearch/common/util/FeatureFlags.java
index 7297479776da9..31dd621f678ad 100644
--- a/server/src/main/java/org/opensearch/common/util/FeatureFlags.java
+++ b/server/src/main/java/org/opensearch/common/util/FeatureFlags.java
@@ -37,6 +37,12 @@ public class FeatureFlags {
      */
     public static final String SEARCHABLE_SNAPSHOT = "opensearch.experimental.feature.searchable_snapshot.enabled";
 
+    /**
+     * Gates the functionality of extensions.
+     * Once the feature is ready for production release, this feature flag can be removed.
+     */
+    public static final String EXTENSIONS = "opensearch.experimental.feature.extensions.enabled";
+
     /**
      * Used to test feature flags whose values are expected to be booleans.
      * This method returns true if the value is "true" (case-insensitive),