Update proto definitions

marketplace/marketplace.proto

@@ -0,0 +1,20 @@
+syntax = "proto3";
+package marketplace;
+option go_package = "./marketplace";
+
+service MarketplaceService {
+
+  rpc GetMarketplaceById(GetMarketplaceByIdRequest) returns (Marketplace);
+}
+
+message GetMarketplaceByIdRequest {
+  uint64 marketplace_id = 1; // ID of the marketplace to retrieve
+}
+message Marketplace {
+  uint64 id = 1;
+  uint32 base_marketplace_id = 2; // ID of the base marketplace
+  string auth_data = 3; // Authentication data for the marketplace
+  string warehouse_id = 4; // ID of the warehouse associated with the marketplace
+}
+
+