diff --git a/core-buffer/include/formats.hpp b/core-buffer/include/formats.hpp
index a48cb8b..ad462b1 100644
--- a/core-buffer/include/formats.hpp
+++ b/core-buffer/include/formats.hpp
@@ -15,6 +15,17 @@ struct ModuleFrame {
 };
 #pragma pack(pop)
 
+
+#pragma pack(push)
+#pragma pack(1)
+struct ImageMetadata {
+    uint64_t pulse_id;
+    uint64_t frame_index;
+    uint32_t daq_rec;
+    uint32_t is_good_frame;
+};
+#pragma pack(pop)
+
 struct ModuleFrameBuffer {
     ModuleFrame module[JUNGFRAU_N_MODULES];
 };