diff --git a/deps/ox/src/ox/model/CMakeLists.txt b/deps/ox/src/ox/model/CMakeLists.txt
index d5270449..b2c59eb2 100644
--- a/deps/ox/src/ox/model/CMakeLists.txt
+++ b/deps/ox/src/ox/model/CMakeLists.txt
@@ -20,6 +20,7 @@ endif()
 
 install(
 	FILES
+		def.hpp
 		descread.hpp
 		desctypes.hpp
 		descwrite.hpp
diff --git a/deps/ox/src/ox/model/def.hpp b/deps/ox/src/ox/model/def.hpp
new file mode 100644
index 00000000..016f7be9
--- /dev/null
+++ b/deps/ox/src/ox/model/def.hpp
@@ -0,0 +1,14 @@
+/*
+ * Copyright 2015 - 2022 gary@drinkingtea.net
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ */
+
+#pragma once
+
+#define oxModelBegin(modelName) template<typename T> constexpr ox::Error model(T *io, modelName *o) noexcept { io->template setTypeInfo<modelName>();
+#define oxModelEnd() return OxError(0); }
+#define oxModelField(fieldName) oxReturnError(io->field(#fieldName, &o->fieldName));
+#define oxModelFriend(modelName) template<typename T> friend ox::Error model(T*, modelName*)
diff --git a/deps/ox/src/ox/model/model.hpp b/deps/ox/src/ox/model/model.hpp
index c768b57c..1ca0a2b0 100644
--- a/deps/ox/src/ox/model/model.hpp
+++ b/deps/ox/src/ox/model/model.hpp
@@ -8,6 +8,7 @@
 
 #pragma once
 
+#include "def.hpp"
 #include "descread.hpp"
 #include "desctypes.hpp"
 #include "descwrite.hpp"