diff --git a/.gitmodules b/.gitmodules
new file mode 100644
index 0000000..3770137
--- /dev/null
+++ b/.gitmodules
@@ -0,0 +1,3 @@
+[submodule "grpc-backend/googleapis"]
+	path = grpc-backend/googleapis
+	url = https://github.com/googleapis/googleapis.git
diff --git a/grpc-backend/googleapis b/grpc-backend/googleapis
new file mode 160000
index 0000000..5c92930
--- /dev/null
+++ b/grpc-backend/googleapis
@@ -0,0 +1 @@
+Subproject commit 5c929307255b1726cdc72855ffc67014fc897d11