add notification messages and disable some lint rules for them

buf.yaml

@@ -5,6 +5,10 @@ modules:
 lint:
   use:
     - STANDARD
+  ignore_only:
+    RPC_REQUEST_STANDARD_NAME:
+      - proto/cmp/services/notification/v1/notify.proto
+  rpc_allow_google_protobuf_empty_responses: true
 breaking:
   use:
     - FILE

proto/cmp/services/book/v1/mint.proto

@@ -79,7 +79,7 @@ message MintResponse {
   // (buyer) bot after the buy operation and passed to the distributor middleware
   // (partner plugin) in the mint response.
   //
-  // This fielld is not meant for the supplier.
+  // This field is not meant for the supplier.
   string buy_transaction_id = 10;
 }
 

proto/cmp/services/notification/v1/notify.proto

@@ -0,0 +1,22 @@
+syntax = "proto3";
+
+package cmp.services.notification.v1;
+
+import "cmp/types/v1/uuid.proto";
+import "google/protobuf/empty.proto";
+
+message TokenBought {
+  uint64 token_id = 1;
+  string tx_id = 2;
+  cmp.types.v1.UUID mint_id = 3;
+}
+
+message TokenExpired {
+  uint64 token_id = 1;
+  cmp.types.v1.UUID mint_id = 2;
+}
+
+service NotificationService {
+  rpc TokenBoughtNotification(TokenBought) returns (google.protobuf.Empty);
+  rpc TokenExpiredNotification(TokenExpired) returns (google.protobuf.Empty);
+}