/enums/reach_plan_surface.proto 

--- v18/enums/reach_plan_surface.proto  2025-08-05 14:36:10.000000000 +0000
+++ v19/enums/reach_plan_surface.proto  2025-08-05 14:36:17.000000000 +0000
@@ -37,6 +37,12 @@
     // The value is unknown in this version.
     UNKNOWN = 1;

+    // Discover feed ad surface.
+    DISCOVER_FEED = 7;
+
+    // Gmail ad surface.
+    GMAIL = 8;
+
     // In-Feed ad surface.
     IN_FEED = 2;