diff --git a/src/api/initialDataTypes.js b/src/api/initialDataTypes.js
index 5ff6a77fc58..fd7987ea75c 100644
--- a/src/api/initialDataTypes.js
+++ b/src/api/initialDataTypes.js
@@ -100,6 +100,14 @@ export type InitialDataRealmFilters = {|
   realm_filters: RealmFilter[],
 |};
 
+// TODO: Make complete and exact.
+export type RawInitialDataRealmUser = {
+  realm_users: Array<{| ...User, avatar_url: string | null |}>,
+  realm_non_active_users: Array<{| ...User, avatar_url: string | null |}>,
+  cross_realm_bots: Array<{| ...CrossRealmBot, avatar_url: string | void | null |}>,
+  ...
+};
+
 export type InitialDataRealmUser = {|
   avatar_source: 'G',
   avatar_url: string | null,
@@ -280,7 +288,17 @@ export type InitialDataUserStatus = {|
   user_status?: UserStatusMapObject,
 |};
 
-// Initial data snapshot sent in response to a `/register` request.
+// Initial data snapshot sent in response to a `/register` request,
+// before validation and transformation.
+//
+// TODO: Make complete and exact.
+export type RawInitialData = {
+  ...RawInitialDataRealmUser,
+  ...
+};
+
+// Initial data snapshot sent in response to a `/register` request,
+// after validation and transformation.
 export type InitialData = {|
   // The server sends different subsets of the full available data,
   // depending on what event types the client subscribes to with the