diff --git a/extensions/phal/fw_update_watch.hpp b/extensions/phal/fw_update_watch.hpp
new file mode 100644
index 0000000..615e10c
--- /dev/null
+++ b/extensions/phal/fw_update_watch.hpp
@@ -0,0 +1,92 @@
+#pragma once
+
+#include <sdbusplus/bus.hpp>
+#include <sdbusplus/server.hpp>
+
+namespace openpower
+{
+namespace phal
+{
+namespace fwupdate
+{
+
+static constexpr auto OBJ_SOFTWARE = "/xyz/openbmc_project/software";
+
+/** @class Watch
+ *  @brief Adds d-bus signal based watch for software path interface add.
+ *  @details This implements methods for watching for software path
+ *  interface add signal and call appropriate function to initiate phal
+ *  devtree attribute data collection and save to preserve partition.
+ *  Rules:
+ *   - Watch for interfaces added for the software path
+ *   - If interface added is “Activation”
+ *   - if Activation property value is “Ready”
+ *   - Then software update is going to start
+ *   - Collect phal devtree required attribute list and save to
+ *     pre-defined location
+ *
+ */
+class Watch
+{
+  public:
+    Watch() = delete;
+    ~Watch() = default;
+    Watch(const Watch&) = delete;
+    Watch& operator=(const Watch&) = delete;
+    Watch(Watch&&) = default;
+    Watch& operator=(Watch&&) = default;
+
+    /** @brief constructs watch for interface add signals.
+     *  @param[in] bus -  The Dbus bus object
+     */
+
+    Watch(sdbusplus::bus::bus& bus) :
+        addMatch(bus,
+                 sdbusplus::bus::match::rules::interfacesAdded() +
+                     sdbusplus::bus::match::rules::path(OBJ_SOFTWARE),
+                 std::bind(std::mem_fn(&Watch::fwIntfAddedCallback), this,
+                           std::placeholders::_1))
+    {}
+
+  private:
+    /** @brief Method to check whether software update is in progress
+     *  @return - bool
+     */
+    bool isSoftwareUpdateInProgress() const
+    {
+        return softwareUpdateInProgress;
+    }
+
+    /** @brief Method to indicate whether software update is in progress
+     *
+     *  @param[in] progress
+     *
+     */
+    void setSoftwareUpdateProgress(bool progress)
+    {
+        softwareUpdateInProgress = progress;
+    }
+
+    /** @brief Callback function for software path add signal.
+     *  @details Function provide required data related to new
+     *  software path interface added to see software update progress.
+     *
+     *  @param[in] msg  - Data associated with subscribed signal
+     */
+    void fwIntfAddedCallback(sdbusplus::message::message& msg);
+
+    /** @brief sdbusplus signal match for software path add */
+    sdbusplus::bus::match_t addMatch;
+
+    /** @brief indicates whether software update is going on */
+    bool softwareUpdateInProgress = false;
+};
+
+/** @brief function to export phal devtree data file based
+ * on the filter file,
+ */
+void exportDevtree();
+
+} // namespace fwupdate
+} // namespace phal
+} // namespace openpower