Implementing list endpoints

services/inventory/design/design.go

@@ -16,8 +16,16 @@ var _ = API("inventory", func() {
 
 var _ = Service("inventory", func() {
 	Description("A GRPC back service that handles CRUD operations for the characters’ inventories")
-	// Method("listItems", func() {
-	// })
+	Method("listInventory", func() {
+		Payload(func() {
+			Field(1, "characterId", Int)
+		})
+		Result(ArrayOf(Int))
+
+		GRPC(func() {
+			Response(CodeOK)
+		})
+	})
 
 	Method("addItem", func() {
 		Payload(design.InventoryRecord)