diff --git a/command/guid.hpp b/command/guid.hpp
index 622b330..5941ef8 100644
--- a/command/guid.hpp
+++ b/command/guid.hpp
@@ -2,7 +2,7 @@
 
 #include <cstddef>
 #include <vector>
-
+#include <sdbusplus/bus/match.hpp>
 #include "comm_module.hpp"
 
 namespace command
@@ -10,12 +10,26 @@
 
 constexpr size_t BMC_GUID_LEN = 16;
 
+using Guid = std::array<uint8_t, BMC_GUID_LEN>;
+
 /**
  * @brief Get System GUID
  *
  * @return If UUID is successfully read from the Chassis DBUS object, then the
  *         GUID is returned, else a canned GUID is returned
  */
-std::array<uint8_t, BMC_GUID_LEN> getSystemGUID();
+Guid getSystemGUID();
+
+/**
+ *  @brief Register the callback to update the cache when the GUID changes
+ */
+void registerGUIDChangeCallback();
 
 } // namespace command
+
+namespace cache
+{
+
+extern command::Guid guid;
+
+} //namespace cache