diff --git a/api/proto/callback/service.proto b/api/proto/callback/service.proto
index d9eea36..f85995e 100644
--- a/api/proto/callback/service.proto
+++ b/api/proto/callback/service.proto
@@ -3,13 +3,14 @@ syntax = "proto3";
 package payment_callback;
 
 import "google/protobuf/empty.proto";
-import "google/protobuf/timestamp.proto";
+//import "google/protobuf/timestamp.proto";
 
 option go_package = "./payment_callback";
 
 service PaymentCallbackService {
   rpc OnSuccess(Event) returns (google.protobuf.Empty) {}
   rpc OnFailure(Event) returns (google.protobuf.Empty) {}
+  rpc OnCartPurchase(Event) returns (google.protobuf.Empty) {}
 }
 
 message Event {