diff --git a/firmware_handler.hpp b/firmware_handler.hpp
index e1c3f85..46497e3 100644
--- a/firmware_handler.hpp
+++ b/firmware_handler.hpp
@@ -28,6 +28,16 @@
 
     /** The flags used to open the session. */
     std::uint16_t flags;
+
+    /** A sesion can be for an image (or tarball) or the hash. */
+    enum State
+    {
+        open = 0,
+        closed = 1,
+    };
+
+    /** The current state of this session. */
+    State state;
 };
 
 struct ExtChunkHdr