diff -r efa901b04bad -r 1aac8a62be6f qmlfrontend/engine_interface.h
--- a/qmlfrontend/engine_interface.h	Thu Nov 22 00:49:55 2018 +0300
+++ b/qmlfrontend/engine_interface.h	Thu Nov 22 10:58:55 2018 +0100
@@ -1,6 +1,7 @@
 #ifndef ENGINE_H
 #define ENGINE_H
 
+#include <stddef.h>
 #include <stdint.h>
 
 #ifdef __cplusplus
@@ -23,11 +24,19 @@
                                 PreviewInfo* preview);
 typedef void cleanup_t(EngineInstance* engine_state);
 
+typedef void send_ipc_t(EngineInstance* engine_state, uint8_t* buf,
+                        size_t size);
+typedef size_t read_ipc_t(EngineInstance* engine_state, uint8_t* buf,
+                          size_t size);
+
 extern protocol_version_t* protocol_version;
 extern start_engine_t* start_engine;
 extern generate_preview_t* generate_preview;
 extern cleanup_t* cleanup;
 
+extern send_ipc_t* send_ipc;
+extern read_ipc_t* read_ipc;
+
 #ifdef __cplusplus
 }
 };