diff --git a/libui/CMakeLists.txt b/libui/CMakeLists.txt
index 79c0deae..4a1adaa2 100644
--- a/libui/CMakeLists.txt
+++ b/libui/CMakeLists.txt
@@ -4,6 +4,8 @@ file(GLOB HEADERS include/ui/*.h)
 
 set(SOURCES
     ${HEADERS}
+    include/ui/ipc/Server.h
+    include/ui/ipc/Client.h
     src/Canvas.cpp
     src/Rect.cpp
     src/Font.cpp
diff --git a/libui/include/ui/ipc/Client.h b/libui/include/ui/ipc/Client.h
new file mode 100644
index 00000000..876f50ef
--- /dev/null
+++ b/libui/include/ui/ipc/Client.h
@@ -0,0 +1,27 @@
+/**
+ * @file ipc/Client.h
+ * @author apio (cloudapio.eu)
+ * @brief IPC message definitions for UI messages sent to the client.
+ *
+ * @copyright Copyright (c) 2023, the Luna authors.
+ *
+ */
+
+#pragma once
+#include <os/IPC.h>
+
+namespace ui
+{
+    enum ClientMessages : u8
+    {
+        IPC_ENUM_CLIENT(ui),
+        CREATE_WINDOW_RESPONSE_ID,
+    };
+
+    struct CreateWindowResponse
+    {
+        static constexpr u8 id = CREATE_WINDOW_RESPONSE_ID;
+
+        int window;
+    };
+}
diff --git a/libui/include/ui/ipc/Server.h b/libui/include/ui/ipc/Server.h
new file mode 100644
index 00000000..bfa4afbe
--- /dev/null
+++ b/libui/include/ui/ipc/Server.h
@@ -0,0 +1,33 @@
+/**
+ * @file ipc/Server.h
+ * @author apio (cloudapio.eu)
+ * @brief IPC message definitions for UI messages sent to the server.
+ *
+ * @copyright Copyright (c) 2023, the Luna authors.
+ *
+ */
+
+#pragma once
+#include <os/IPC.h>
+#include <ui/Color.h>
+#include <ui/Rect.h>
+#include <ui/ipc/Client.h>
+
+namespace ui
+{
+    enum ServerMessages : u8
+    {
+        IPC_ENUM_SERVER(ui),
+        CREATE_WINDOW_ID,
+    };
+
+    struct CreateWindowRequest
+    {
+        using ResponseType = CreateWindowResponse;
+        static constexpr u8 id = CREATE_WINDOW_ID;
+
+        ui::Rect rect;
+        IPC_STRING(name);
+        ui::Color color;
+    };
+}