diff --git a/src/libslic3r/GCode.cpp b/src/libslic3r/GCode.cpp
index 3e8a6478c6..1a1d1bcbff 100644
--- a/src/libslic3r/GCode.cpp
+++ b/src/libslic3r/GCode.cpp
@@ -8,6 +8,7 @@
 #include "I18N.hpp"
 #include "GCode.hpp"
 #include "Exception.hpp"
+#include "LifecycleEvents.hpp"
 #include "ExtrusionEntity.hpp"
 #include "EdgeGrid.hpp"
 #include "Geometry/ConvexHull.hpp"
@@ -2476,6 +2477,15 @@ void GCode::do_export(Print* print, const char* path, GCodeProcessorResult* resu
     m_writer.set_is_bbl_machine(print->is_BBL_printer());
     print->set_started(psGCodeExport);
 
+    {
+        LifecycleEventContext ctx;
+        ctx.name = std::to_string(print->model().id().id);
+        ctx.code = LifecycleEvtCode::Ok;
+        ctx.msg  = path;
+        ctx.cancellation_check = [print]() { return print->canceled(); };
+        fire_lifecycle_event(LifecycleEvent::GCodeExportStarted, ctx);
+    }
+
     // check if any custom gcode contains keywords used by the gcode processor to
     // produce time estimation and gcode toolpaths
     std::vector<std::pair<std::string, std::string>> validation_res = DoExport::validate_custom_gcode(*print);
@@ -2511,12 +2521,23 @@ void GCode::do_export(Print* print, const char* path, GCodeProcessorResult* resu
     m_processor.set_print(print);
     GCodeOutputStream file(boost::nowide::fopen(path_tmp.c_str(), "wb"), m_processor);
     if (! file.is_open()) {
-        BOOST_LOG_TRIVIAL(error) << std::string("G-code export to ") + path + " failed.\nCannot open the file for writing.\n" << std::endl;
+        std::string err_msg = std::string("G-code export to ") + path + " failed.\nCannot open the file for writing.\n";
+        BOOST_LOG_TRIVIAL(error) << err_msg << std::endl;
         if (!fs::exists(folder)) {
             //fs::create_directory(folder);
-            BOOST_LOG_TRIVIAL(error) << "the parent path " + folder.string() +" is not there!!!" << std::endl;
+            std::string add_err_msg = "the parent path " + folder.string() +" is not there!!!";
+            BOOST_LOG_TRIVIAL(error) << add_err_msg << std::endl;
+            err_msg += add_err_msg;
         }
-        throw Slic3r::RuntimeError(std::string("G-code export to ") + path + " failed.\nCannot open the file for writing.\n");
+        {
+            LifecycleEventContext ctx;
+            ctx.name = std::to_string(print->model().id().id);
+            ctx.code = LifecycleEvtCode::Error;
+            ctx.msg  = std::string(path) + "\n" + err_msg;
+            ctx.cancellation_check = [print]() { return print->canceled(); };
+            fire_lifecycle_event(LifecycleEvent::GCodeExportFinished, ctx);
+        }
+        throw Slic3r::RuntimeError(err_msg);
     }
 
     try {
@@ -2527,11 +2548,19 @@ void GCode::do_export(Print* print, const char* path, GCodeProcessorResult* resu
             boost::nowide::remove(path_tmp.c_str());
             throw Slic3r::RuntimeError(std::string("G-code export to ") + path + " failed\nIs the disk full?\n");
         }
-    } catch (std::exception & /* ex */) {
+    } catch (std::exception &ex) {
         // Rethrow on any exception. std::runtime_exception and CanceledException are expected to be thrown.
         // Close and remove the file.
         file.close();
         boost::nowide::remove(path_tmp.c_str());
+        {
+            LifecycleEventContext ctx;
+            ctx.name = std::to_string(print->model().id().id);
+            ctx.code = LifecycleEvtCode::Error;
+            ctx.msg  = std::string(path) + "\n" + ex.what();
+            ctx.cancellation_check = [print]() { return print->canceled(); };
+            fire_lifecycle_event(LifecycleEvent::GCodeExportFinished, ctx);
+        }
         throw;
     }
     file.close();
@@ -2637,6 +2666,14 @@ void GCode::do_export(Print* print, const char* path, GCodeProcessorResult* resu
 
     std::error_code ret = rename_file(path_tmp, path);
     if (ret) {
+        {
+            LifecycleEventContext ctx;
+            ctx.name = std::to_string(print->model().id().id);
+            ctx.code = LifecycleEvtCode::Error;
+            ctx.msg  = std::string(path) + "\nFailed to rename the output G-code file: " + ret.message();
+            ctx.cancellation_check = [print]() { return print->canceled(); };
+            fire_lifecycle_event(LifecycleEvent::GCodeExportFinished, ctx);
+        }
         throw Slic3r::RuntimeError(
             std::string("Failed to rename the output G-code file from ") + path_tmp + " to " + path + '\n' + "error code " + ret.message() + '\n' +
             "Is " + path_tmp + " locked?" + '\n');
@@ -2647,7 +2684,16 @@ void GCode::do_export(Print* print, const char* path, GCodeProcessorResult* resu
 
     BOOST_LOG_TRIVIAL(info) << "Exporting G-code finished" << log_memory_info();
     print->set_done(psGCodeExport);
-    
+
+    {
+        LifecycleEventContext ctx;
+        ctx.name = std::to_string(print->model().id().id);
+        ctx.code = LifecycleEvtCode::Ok;
+        ctx.msg  = path;
+        ctx.cancellation_check = [print]() { return print->canceled(); };
+        fire_lifecycle_event(LifecycleEvent::GCodeExportFinished, ctx);
+    }
+
     // Orca: label_object_enabled reflects whether objects are labeled in the g-code (EXCLUDE_OBJECT /
     // M486), which is driven by exclude_object for every printer
     if(result != nullptr)
diff --git a/src/libslic3r/LifecycleEvents.hpp b/src/libslic3r/LifecycleEvents.hpp
new file mode 100644
index 0000000000..f3e6f32392
--- /dev/null
+++ b/src/libslic3r/LifecycleEvents.hpp
@@ -0,0 +1,249 @@
+#pragma once
+
+// LifecycleEvents.hpp
+// --------------------
+// Application lifecycle events (project, slicing, plate editing, preset, printer connection, and
+// job activity) that other subsystems -- chiefly the plugin layer above libslic3r -- may want to
+// observe. Lives in libslic3r rather than the plugin layer because some events fire from inside
+// the slicing engine itself; see fire_lifecycle_event() below.
+
+#include <functional>
+#include <condition_variable>
+#include <cstddef>
+#include <mutex>
+#include <string>
+#include <utility>
+
+namespace Slic3r
+{
+    enum class LifecycleEvent {
+        // Project (3mf)
+        NewProject,
+        ProjectOpened,
+        ProjectBeforeSave,
+        ProjectAfterSave,
+        ProjectClosed,
+        ProjectDirtyChanged,
+
+        // Slicing pipeline
+        SliceStarted,
+        SliceGeometryFinished,
+        GCodeExportStarted,
+        GCodeExportFinished,
+        SlicingJobComplete,
+
+        // Plate/model editing
+        ObjectAdded,
+        ObjectDeleted,
+        ObjectTransformed,
+        ObjectChanged,
+        ObjectRenamed,
+        PlateCreated,
+        PlateDeleted,
+        PlateSelected,
+        PlateRenamed,
+
+        // Preset
+        PresetSelected,
+        PresetSaved,
+
+        // Printer/device
+        PrintStateChanged,
+        DeviceOnline,
+        DeviceOffline,
+        DeviceDiscovered,
+        DeviceSelected,
+        UploadStarted,
+        UploadFinished,
+
+        // Print/send jobs
+        PrintJobStarted,
+        PrintJobFinished,
+        SendJobStarted,
+        SendJobFinished,
+    };
+
+    // Scoped so callers must qualify (LifecycleEvtCode::Error, not ERROR) -- ERROR/OK collide with
+    // Windows macros (wingdi.h) as unqualified names.
+    enum class LifecycleEvtCode { Ok, Error, Warn };
+
+    struct LifecycleEventContext
+    {
+        // The primary subject identifier for the event. This is event-specific (for example, a
+        // project/output path, preset name, device id, or object name), must not contain status or
+        // prose, and may be empty when the event has no single subject.
+        std::string name;
+
+        // Outcome of the operation represented by the event. For state-change and start events,
+        // Ok means that the event occurred; it does not imply that a future operation succeeded.
+        LifecycleEvtCode code = LifecycleEvtCode::Ok;
+
+        // Optional human-readable detail or diagnostic text. It is not a stable parsing contract;
+        // machine-readable data should be represented by a dedicated field or event instead.
+        std::string msg;
+
+        // Stable subject/object identifier, when the source model provides one.
+        std::string id;
+
+        // Previous value for rename and other before/after events.
+        std::string previous_name;
+
+        // Device identifier for printer and job events.
+        std::string device_id;
+
+        // Job identifier when the originating queue/task provides one.
+        std::string job_id;
+
+        // Source subsystem or operation detail, suitable for filtering but not guaranteed to be
+        // exhaustive across versions.
+        std::string source;
+
+        // Plate, object, or volume index when the source uses an index rather than a stable id.
+        int index = -1;
+
+        // Aggregate project dirty state for ProjectDirtyChanged.
+        bool dirty = false;
+
+        // Optional host-side cancellation probe. Background slicing and G-code export events set
+        // this to the originating Print's cancellation state so dispatch can stop before calling
+        // the next capability. It is intentionally not exposed through the Python payload API.
+        std::function<bool()> cancellation_check;
+    };
+
+    inline std::string lifecycle_event_to_string(LifecycleEvent event)
+    {
+        switch (event) {
+        case LifecycleEvent::NewProject: return "NewProject";
+        case LifecycleEvent::ProjectOpened: return "ProjectOpened";
+        case LifecycleEvent::ProjectBeforeSave: return "ProjectBeforeSave";
+        case LifecycleEvent::ProjectAfterSave: return "ProjectAfterSave";
+        case LifecycleEvent::ProjectClosed: return "ProjectClosed";
+        case LifecycleEvent::ProjectDirtyChanged: return "ProjectDirtyChanged";
+
+        case LifecycleEvent::SliceStarted: return "SliceStarted";
+        case LifecycleEvent::SliceGeometryFinished: return "SliceGeometryFinished";
+        case LifecycleEvent::GCodeExportStarted: return "GCodeExportStarted";
+        case LifecycleEvent::GCodeExportFinished: return "GCodeExportFinished";
+        case LifecycleEvent::SlicingJobComplete: return "SlicingJobComplete";
+
+        case LifecycleEvent::ObjectAdded: return "ObjectAdded";
+        case LifecycleEvent::ObjectDeleted: return "ObjectDeleted";
+        case LifecycleEvent::ObjectTransformed: return "ObjectTransformed";
+        case LifecycleEvent::ObjectChanged: return "ObjectChanged";
+        case LifecycleEvent::ObjectRenamed: return "ObjectRenamed";
+        case LifecycleEvent::PlateCreated: return "PlateCreated";
+        case LifecycleEvent::PlateDeleted: return "PlateDeleted";
+        case LifecycleEvent::PlateSelected: return "PlateSelected";
+        case LifecycleEvent::PlateRenamed: return "PlateRenamed";
+
+        case LifecycleEvent::PresetSelected: return "PresetSelected";
+        case LifecycleEvent::PresetSaved: return "PresetSaved";
+        case LifecycleEvent::PrintStateChanged: return "PrintStateChanged";
+
+        case LifecycleEvent::DeviceOnline: return "DeviceOnline";
+        case LifecycleEvent::DeviceOffline: return "DeviceOffline";
+        case LifecycleEvent::DeviceDiscovered: return "DeviceDiscovered";
+        case LifecycleEvent::DeviceSelected: return "DeviceSelected";
+
+        case LifecycleEvent::UploadStarted: return "UploadStarted";
+        case LifecycleEvent::UploadFinished: return "UploadFinished";
+        case LifecycleEvent::PrintJobStarted: return "PrintJobStarted";
+        case LifecycleEvent::PrintJobFinished: return "PrintJobFinished";
+        case LifecycleEvent::SendJobStarted: return "SendJobStarted";
+        case LifecycleEvent::SendJobFinished: return "SendJobFinished";
+        default: return "Unknown";
+        }
+    }
+
+    inline std::string lifecycle_evt_code_to_string(LifecycleEvtCode code)
+    {
+        switch (code) {
+        case LifecycleEvtCode::Ok: return "Ok";
+        case LifecycleEvtCode::Error: return "Error";
+        case LifecycleEvtCode::Warn: return "Warn";
+        default: return "Unknown";
+        }
+    }
+
+    // Global cross-layer seam (mirrors ConfigBase::set_resolve_capability_fn): any libslic3r code can
+    // fire a lifecycle event without depending on the plugin layer above it, which installs the
+    // dispatcher here at startup. Not tied to Print/GCode specifically, since nothing here should
+    // require callers to hold a Print& just to report an event.
+    using LifecycleHookFn = std::function<void(LifecycleEvent, const LifecycleEventContext&)>;
+
+    namespace detail {
+
+    struct LifecycleHookState
+    {
+        std::mutex              mutex;
+        std::condition_variable cv;
+        LifecycleHookFn         fn;
+        std::size_t             active_dispatches = 0;
+        bool                    accepting        = false;
+    };
+
+    inline LifecycleHookState& lifecycle_hook_state()
+    {
+        static LifecycleHookState state;
+        return state;
+    }
+
+    class LifecycleDispatchGuard
+    {
+    public:
+        explicit LifecycleDispatchGuard(LifecycleHookState& state) : m_state(state) {}
+
+        ~LifecycleDispatchGuard()
+        {
+            std::lock_guard<std::mutex> lock(m_state.mutex);
+            --m_state.active_dispatches;
+            if (m_state.active_dispatches == 0)
+                m_state.cv.notify_all();
+        }
+
+        LifecycleDispatchGuard(const LifecycleDispatchGuard&)            = delete;
+        LifecycleDispatchGuard& operator=(const LifecycleDispatchGuard&) = delete;
+
+    private:
+        LifecycleHookState& m_state;
+    };
+
+    } // namespace detail
+
+    // Installing a hook starts accepting dispatches. Passing an empty function stops accepting
+    // new dispatches, detaches the hook, and waits for callbacks already in progress to finish.
+    // This is used during plugin shutdown so plugin code cannot be unloaded while a lifecycle
+    // callback is still executing. The empty-function path must not be called from inside the
+    // lifecycle callback itself.
+    inline void set_lifecycle_hook_fn(LifecycleHookFn fn)
+    {
+        detail::LifecycleHookState& state = detail::lifecycle_hook_state();
+        if (fn) {
+            std::lock_guard<std::mutex> lock(state.mutex);
+            state.fn        = std::move(fn);
+            state.accepting = true;
+            return;
+        }
+
+        std::unique_lock<std::mutex> lock(state.mutex);
+        state.accepting = false;
+        state.fn        = nullptr;
+        state.cv.wait(lock, [&state] { return state.active_dispatches == 0; });
+    }
+
+    inline void fire_lifecycle_event(LifecycleEvent event, const LifecycleEventContext& ctx)
+    {
+        detail::LifecycleHookState& state = detail::lifecycle_hook_state();
+        LifecycleHookFn             fn;
+        {
+            std::lock_guard<std::mutex> lock(state.mutex);
+            if (!state.accepting || !state.fn)
+                return;
+            fn = state.fn;
+            ++state.active_dispatches;
+        }
+
+        detail::LifecycleDispatchGuard guard(state);
+        fn(event, ctx);
+    }
+}
diff --git a/src/libslic3r/Preset.cpp b/src/libslic3r/Preset.cpp
index 1002f5be89..214ef229df 100644
--- a/src/libslic3r/Preset.cpp
+++ b/src/libslic3r/Preset.cpp
@@ -47,6 +47,7 @@
 #include <boost/log/trivial.hpp>
 
 #include "libslic3r.h"
+#include "LifecycleEvents.hpp"
 #include "Utils.hpp"
 #include "Time.hpp"
 #include "PlaceholderParser.hpp"
@@ -2972,6 +2973,7 @@ void PresetCollection::save_current_preset(const std::string &new_name, bool det
     // 1) Find the preset with a new_name or create a new one,
     // initialize it with the edited config.
     auto it = this->find_preset_internal(new_name);
+    const bool preset_existed = (it != m_presets.end() && it->name == new_name);
     if (it != m_presets.end() && it->name == new_name) {
         // Preset with the same name found.
         Preset &preset = *it;
@@ -3079,6 +3081,14 @@ void PresetCollection::save_current_preset(const std::string &new_name, bool det
         this->get_selected_preset().save(&(parent_preset->config));
     else
         this->get_selected_preset().save(nullptr);
+
+    {
+        LifecycleEventContext ctx;
+        ctx.name  = new_name;
+        ctx.msg = preset_existed ? "overwrite" : "new";
+        ctx.code = LifecycleEvtCode::Ok;
+        fire_lifecycle_event(LifecycleEvent::PresetSaved, ctx);
+    }
 }
 
 // A detached standalone preset for the Full Publish receiver: create a user preset holding
diff --git a/src/libslic3r/Print.cpp b/src/libslic3r/Print.cpp
index 833b811535..5df69b7335 100644
--- a/src/libslic3r/Print.cpp
+++ b/src/libslic3r/Print.cpp
@@ -14,6 +14,7 @@
 #include "Flow.hpp"
 #include "Geometry/ConvexHull.hpp"
 #include "I18N.hpp"
+#include "LifecycleEvents.hpp"
 #include "ShortestPath.hpp"
 #include "Thread.hpp"
 #include "Time.hpp"
@@ -2694,6 +2695,14 @@ void Print::process(long long *time_cost_with_cache, bool use_cache)
     if (m_objects.empty())
         return;
 
+    {
+        LifecycleEventContext ctx;
+        ctx.name = std::to_string(m_model.id().id);
+        ctx.code = LifecycleEvtCode::Ok;
+        ctx.cancellation_check = [this]() { return canceled(); };
+        fire_lifecycle_event(LifecycleEvent::SliceStarted, ctx);
+    }
+
     for (PrintObject *obj : m_objects)
         obj->clear_shared_object();
 
@@ -3312,6 +3321,14 @@ void Print::process(long long *time_cost_with_cache, bool use_cache)
     }
 
     BOOST_LOG_TRIVIAL(info) << "Slicing process finished." << log_memory_info();
+
+    {
+        LifecycleEventContext ctx;
+        ctx.name = std::to_string(m_model.id().id);
+        ctx.code = LifecycleEvtCode::Ok;
+        ctx.cancellation_check = [this]() { return canceled(); };
+        fire_lifecycle_event(LifecycleEvent::SliceGeometryFinished, ctx);
+    }
 }
 
 // G-code export process, running at a background thread.
@@ -4911,6 +4928,15 @@ void Print::set_gcode_file_invalidated()
 //BBS: add gcode file preload logic
 void Print::export_gcode_from_previous_file(const std::string& file, GCodeProcessorResult* result, ThumbnailsGeneratorCallback thumbnail_cb)
 {
+    {
+        LifecycleEventContext ctx;
+        ctx.name = std::to_string(m_model.id().id);
+        ctx.code = LifecycleEvtCode::Ok;
+        ctx.msg  = file;
+        ctx.cancellation_check = [this]() { return canceled(); };
+        fire_lifecycle_event(LifecycleEvent::GCodeExportStarted, ctx);
+    }
+
     try {
         GCodeProcessor processor;
         GCodeProcessor::s_IsBBLPrinter = is_BBL_printer();
@@ -4930,13 +4956,30 @@ void Print::export_gcode_from_previous_file(const std::string& file, GCodeProces
         *result = std::move(processor.extract_result());
         result->filament_change_sequence = filament_seq_loaded;
         result->nozzle_change_sequence   = nozzle_seq_loaded;
-    } catch (std::exception & /* ex */) {
+    } catch (std::exception &ex) {
         BOOST_LOG_TRIVIAL(error) << __FUNCTION__ <<  boost::format(": found errors when process gcode file %1%") %file.c_str();
+        {
+            LifecycleEventContext ctx;
+            ctx.name = std::to_string(m_model.id().id);
+            ctx.code = LifecycleEvtCode::Error;
+            ctx.msg  = file + "\n" + ex.what();
+            ctx.cancellation_check = [this]() { return canceled(); };
+            fire_lifecycle_event(LifecycleEvent::GCodeExportFinished, ctx);
+        }
         throw Slic3r::RuntimeError(
             std::string("Failed to process the G-code file ") + file + " from previous 3mf\n");
     }
 
     BOOST_LOG_TRIVIAL(info) << __FUNCTION__ <<  boost::format(":  process the G-code file %1% successfully")%file.c_str();
+
+    {
+        LifecycleEventContext ctx;
+        ctx.name = std::to_string(m_model.id().id);
+        ctx.code = LifecycleEvtCode::Ok;
+        ctx.msg  = file;
+        ctx.cancellation_check = [this]() { return canceled(); };
+        fire_lifecycle_event(LifecycleEvent::GCodeExportFinished, ctx);
+    }
 }
 
 std::tuple<float, float> Print::object_skirt_offset(double margin_height) const
diff --git a/src/slic3r/GUI/DeviceCore/DevManager.cpp b/src/slic3r/GUI/DeviceCore/DevManager.cpp
index feb6301df3..c03f0cfe59 100644
--- a/src/slic3r/GUI/DeviceCore/DevManager.cpp
+++ b/src/slic3r/GUI/DeviceCore/DevManager.cpp
@@ -10,6 +10,7 @@
 #include "slic3r/GUI/I18N.hpp"
 #include "slic3r/GUI/GUI_App.hpp"
 #include "slic3r/GUI/Plater.hpp"
+#include "slic3r/plugin/PluginManager.hpp"
 #include "slic3r/Utils/NetworkAgentFactory.hpp"
 
 #include "libslic3r/Time.hpp"
@@ -355,7 +356,10 @@ namespace Slic3r
                     obj->bind_state = "free";
 
                 obj->last_alive = Slic3r::Utils::get_current_time_utc();
-                obj->m_is_online = true;
+                // Route through set_online_state() (rather than writing m_is_online directly) so the
+                // DeviceOnline lifecycle event fires consistently; same effective value/behavior
+                // here since the object was already online in the common case.
+                obj->set_online_state(true);
                 obj->set_dev_name(dev_name);
                 /* if (!obj->dev_ip.empty()) {
                 Slic3r::GUI::wxGetApp().app_config->set_str("ip_address", obj->dev_id, obj->dev_ip);
@@ -373,6 +377,10 @@ namespace Slic3r
                 obj->bind_sec_link  = sec_link;
                 obj->dev_connection_name = connection_name;
                 obj->bind_ssdp_version = ssdp_version;
+                // Discovery establishes the initial reachability state. Do not report it as an
+                // online transition; DeviceDiscovered below is the lifecycle event for a new
+                // device. Subsequent updates route through set_online_state(), so a known device
+                // still emits DeviceOnline/DeviceOffline when its reachability actually changes.
                 obj->m_is_online = true;
 
                 //load access code
@@ -389,6 +397,15 @@ namespace Slic3r
                 BOOST_LOG_TRIVIAL(info) << __FUNCTION__ << " New Machine, dev_id= " << dev_id
                     << ", ip = " << dev_ip <<", printer_name = " << dev_name
                     << ", con_type= " << connect_type <<", signal= " << printer_signal << ", bind_state= " << bind_state;
+
+                // First discovery of a genuinely new device (not a periodic SSDP/heartbeat update to
+                // an already-known one, which is handled in the branch above).
+                {
+                    LifecycleEventContext ctx;
+                    ctx.name = dev_id;
+                    ctx.code = LifecycleEvtCode::Ok;
+                    fire_lifecycle_event(LifecycleEvent::DeviceDiscovered, ctx);
+                }
             }
             update_local_machine(*obj);
         }
@@ -984,8 +1001,14 @@ namespace Slic3r
     }
 
     void DeviceManager::OnSelectedMachineChanged(const std::string& /*pre_dev_id*/,
-                                                 const std::string& /*new_dev_id*/)
+                                                 const std::string& new_dev_id)
     {
+        {
+            LifecycleEventContext ctx;
+            ctx.name = new_dev_id; // empty string is a valid deselection
+            ctx.code = LifecycleEvtCode::Ok;
+            fire_lifecycle_event(LifecycleEvent::DeviceSelected, ctx);
+        }
         if (MachineObject* obj_ = get_selected_machine()) {
             GUI::wxGetApp().sidebar().update_sync_status(obj_);
             if(m_agent->get_filament_sync_mode() == FilamentSyncMode::subscription)
diff --git a/src/slic3r/GUI/DeviceManager.cpp b/src/slic3r/GUI/DeviceManager.cpp
index fd60f80d25..6bd690e9a6 100644
--- a/src/slic3r/GUI/DeviceManager.cpp
+++ b/src/slic3r/GUI/DeviceManager.cpp
@@ -5,6 +5,7 @@
 #include "libslic3r/Time.hpp"
 #include "libslic3r/Thread.hpp"
 #include "slic3r/Utils/NetworkAgent.hpp"
+#include "slic3r/plugin/PluginManager.hpp"
 #include "slic3r/Utils/NetworkAgentFactory.hpp"
 #include "GuiColor.hpp"
 
@@ -2626,7 +2627,15 @@ void MachineObject::reset()
 
 void MachineObject::set_print_state(std::string status)
 {
+    const bool changed = (print_status != status);
     print_status = status;
+    if (changed) {
+        LifecycleEventContext ctx;
+        ctx.name  = dev_id;
+        ctx.code  = LifecycleEvtCode::Ok;
+        ctx.msg   = print_status;
+        fire_lifecycle_event(LifecycleEvent::PrintStateChanged, ctx);
+    }
 }
 
 int MachineObject::connect(bool use_openssl)
@@ -2648,7 +2657,10 @@ int MachineObject::connect(bool use_openssl)
 int MachineObject::disconnect()
 {
     if (m_agent) {
-        return m_agent->disconnect_printer();
+        const int result = m_agent->disconnect_printer();
+        if (result == 0)
+            set_online_state(false);
+        return result;
     }
     return -1;
 }
@@ -2678,8 +2690,16 @@ bool MachineObject::is_connecting()
 
 void MachineObject::set_online_state(bool on_off)
 {
+    const bool changed = (m_is_online != on_off);
     m_is_online = on_off;
     if (!on_off) m_active_state = NotActive;
+    if (changed) {
+        LifecycleEventContext ctx;
+        ctx.name  = dev_id;
+        ctx.code  = LifecycleEvtCode::Ok;
+        ctx.msg   = on_off ? "online" : "offline";
+        fire_lifecycle_event(on_off ? LifecycleEvent::DeviceOnline : LifecycleEvent::DeviceOffline, ctx);
+    }
 }
 
 bool MachineObject::is_info_ready(bool check_version) const
@@ -2806,13 +2826,6 @@ int MachineObject::parse_json(std::string tunnel, std::string payload, bool key_
 
     parse_msg_count++;
     std::chrono::system_clock::time_point clock_start = std::chrono::system_clock::now();
-    this->set_online_state(true);
-
-    std::chrono::system_clock::time_point curr_time = std::chrono::system_clock::now();
-    auto diff1 = std::chrono::duration_cast<std::chrono::microseconds>(curr_time - last_update_time);
-
-    /* update last received time */
-    last_update_time = std::chrono::system_clock::now();
 
     json j_pre;
     bool parse_ok = false;
@@ -2825,8 +2838,29 @@ int MachineObject::parse_json(std::string tunnel, std::string payload, bool key_
         /* post process payload */
         sanitizeToUtf8(payload);
         BOOST_LOG_TRIVIAL(info) << "parse_json: sanitize to utf8";
+        try {
+            j_pre = json::parse(payload);
+            parse_ok = true;
+        }
+        catch (...) {}
     }
 
+    bool client_disconnected = false;
+    if (parse_ok && j_pre.is_object() && j_pre.contains("event") && j_pre["event"].is_object() &&
+        j_pre["event"].contains("event") && j_pre["event"]["event"].is_string()) {
+        client_disconnected = j_pre["event"]["event"].get<std::string>() == "client.disconnected";
+    }
+
+    // A disconnect notification is a transport message too, but it must not first mark an
+    // already-offline device as online through the generic message-received path.
+    set_online_state(!client_disconnected);
+
+    std::chrono::system_clock::time_point curr_time = std::chrono::system_clock::now();
+    auto diff1 = std::chrono::duration_cast<std::chrono::microseconds>(curr_time - last_update_time);
+
+    /* update last received time */
+    last_update_time = std::chrono::system_clock::now();
+
     try {
         bool restored_json = false;
         json j;
@@ -4597,19 +4631,6 @@ int MachineObject::parse_json(std::string tunnel, std::string payload, bool key_
             }
         }
 
-        // event info
-        try {
-            if (j.contains("event")) {
-                if (j["event"].contains("event")) {
-                    if (j["event"]["event"].get<std::string>() == "client.disconnected")
-                        set_online_state(false);
-                    else if (j["event"]["event"].get<std::string>() == "client.connected")
-                        set_online_state(true);
-                }
-            }
-        }
-        catch (...)  {}
-
         if (!key_field_only) {
             BOOST_LOG_TRIVIAL(trace) << "parse_json  m_active_state =" << m_active_state;
             parse_state_changed_event();
diff --git a/src/slic3r/GUI/DeviceManager.hpp b/src/slic3r/GUI/DeviceManager.hpp
index 914c8f7868..ca3b7c3c44 100644
--- a/src/slic3r/GUI/DeviceManager.hpp
+++ b/src/slic3r/GUI/DeviceManager.hpp
@@ -897,6 +897,7 @@ public:
 
     bool is_connected();
     bool is_connecting();
+    // Emits DeviceOnline or DeviceOffline only when the reachability state changes.
     void set_online_state(bool on_off);
     bool is_online() { return m_is_online; }
     bool is_info_ready(bool check_version = true) const;
diff --git a/src/slic3r/GUI/GLCanvas3D.cpp b/src/slic3r/GUI/GLCanvas3D.cpp
index b76c7f346c..887d13aedc 100644
--- a/src/slic3r/GUI/GLCanvas3D.cpp
+++ b/src/slic3r/GUI/GLCanvas3D.cpp
@@ -43,6 +43,7 @@
 #include "slic3r/GUI/Gizmos/GLGizmoPainterBase.hpp"
 #include "slic3r/Utils/UndoRedo.hpp"
 #include "slic3r/Utils/MacDarkMode.hpp"
+#include "slic3r/plugin/PluginManager.hpp"
 
 #include <slic3r/GUI/GUI_Utils.hpp>
 
@@ -5028,8 +5029,16 @@ void GLCanvas3D::do_move(const std::string& snapshot_type)
     //BBS: nofity object list to update
     wxGetApp().plater()->sidebar().obj_list()->update_plate_values_for_items();
 
-    if (object_moved)
+    if (object_moved) {
+        Slic3r::LifecycleEventContext ctx;
+        ctx.code = Slic3r::LifecycleEvtCode::Ok;
+        ctx.msg = "moved";
+        if (done.size() == 1)
+            ctx.name = m_model->objects[done.begin()->first]->name;
+        Slic3r::fire_lifecycle_event(Slic3r::LifecycleEvent::ObjectTransformed, ctx);
+
         post_event(SimpleEvent(EVT_GLCANVAS_INSTANCE_MOVED));
+    }
 
     // BBS: support wipe-tower for multi-plates
     for (int plate_id = 0; plate_id < wipe_tower_origins.size(); plate_id++) {
@@ -5150,8 +5159,16 @@ void GLCanvas3D::do_rotate(const std::string& snapshot_type)
     //BBS: nofity object list to update
     wxGetApp().plater()->sidebar().obj_list()->update_plate_values_for_items();
 
-    if (!done.empty())
+    if (!done.empty()) {
+        Slic3r::LifecycleEventContext ctx;
+        ctx.code = Slic3r::LifecycleEvtCode::Ok;
+        ctx.msg = "rotated";
+        if (done.size() == 1)
+            ctx.name = m_model->objects[done.begin()->first]->name;
+        Slic3r::fire_lifecycle_event(Slic3r::LifecycleEvent::ObjectTransformed, ctx);
+
         post_event(SimpleEvent(EVT_GLCANVAS_INSTANCE_ROTATED));
+    }
 
     m_dirty = true;
 }
@@ -5242,8 +5259,16 @@ void GLCanvas3D::do_scale(const std::string& snapshot_type)
     //BBS: notify object info update
     wxGetApp().plater()->show_object_info();
 
-    if (!done.empty())
+    if (!done.empty()) {
+        Slic3r::LifecycleEventContext ctx;
+        ctx.code = Slic3r::LifecycleEvtCode::Ok;
+        ctx.msg = "scaled";
+        if (done.size() == 1)
+            ctx.name = m_model->objects[done.begin()->first]->name;
+        Slic3r::fire_lifecycle_event(Slic3r::LifecycleEvent::ObjectTransformed, ctx);
+
         post_event(SimpleEvent(EVT_GLCANVAS_INSTANCE_SCALED));
+    }
 
     m_dirty = true;
 }
diff --git a/src/slic3r/GUI/GUI_App.cpp b/src/slic3r/GUI/GUI_App.cpp
index 48bd58b1a5..29bab18aeb 100644
--- a/src/slic3r/GUI/GUI_App.cpp
+++ b/src/slic3r/GUI/GUI_App.cpp
@@ -2182,6 +2182,8 @@ void GUI_App::init_networking_callbacks()
                     obj->command_get_access_code();
                     if (m_agent)
                         m_agent->install_device_cert(obj->get_dev_id(), obj->is_lan_mode_printer());
+
+                    obj->set_online_state(true);
                 }
                 });
             });
@@ -2220,6 +2222,8 @@ void GUI_App::init_networking_callbacks()
                                 obj->command_get_version();
                                 event.SetInt(0);
                                 event.SetString(obj->get_dev_id());
+
+                                obj->set_online_state(true);
                             } else if (state == ConnectStatus::ConnectStatusFailed) {
                                 // Orca: only update status if same device id
                                 if (m_device_manager->selected_machine != dev_id) return;
@@ -2235,10 +2239,14 @@ void GUI_App::init_networking_callbacks()
                                     wxGetApp().show_dialog(text);
                                 }
                                 event.SetInt(-1);
+
+                                obj->set_online_state(false);
                             } else if (state == ConnectStatus::ConnectStatusLost) {
                                 m_device_manager->set_selected_machine("");
                                 event.SetInt(-1);
                                 BOOST_LOG_TRIVIAL(info) << "set_on_local_connect_fn: state = lost";
+
+                                obj->set_online_state(false);
                             } else {
                                 event.SetInt(-1);
                                 BOOST_LOG_TRIVIAL(info) << "set_on_local_connect_fn: state = " << state;
diff --git a/src/slic3r/GUI/GUI_ObjectList.cpp b/src/slic3r/GUI/GUI_ObjectList.cpp
index 2d77200eef..5220e026c7 100644
--- a/src/slic3r/GUI/GUI_ObjectList.cpp
+++ b/src/slic3r/GUI/GUI_ObjectList.cpp
@@ -1,5 +1,6 @@
 #include "libslic3r/libslic3r.h"
 #include "libslic3r/PresetBundle.hpp"
+#include "libslic3r/LifecycleEvents.hpp"
 #include "GUI_ObjectList.hpp"
 #include "GUI_Factories.hpp"
 //#include "GUI_ObjectLayers.hpp"
@@ -10,6 +11,7 @@
 #include "BitmapComboBox.hpp"
 #include "MainFrame.hpp"
 #include "slic3r/Utils/UndoRedo.hpp"
+#include "slic3r/plugin/PluginManager.hpp"
 
 #include "OptionsGroup.hpp"
 #include "Tab.hpp"
@@ -1159,17 +1161,39 @@ void ObjectList::update_name_in_model(const wxDataViewItem& item) const
     if (m_objects_model->GetItemType(item) & itObject) {
         std::string name = m_objects_model->GetName(item).ToUTF8().data();
         if (obj->name != name) {
+            const std::string previous_name = obj->name;
             obj->name = name;
             // if object has just one volume, rename this volume too
             if (obj->volumes.size() == 1)
                 obj->volumes[0]->name = obj->name;
             Slic3r::save_object_mesh(*obj);
+
+            LifecycleEventContext ctx;
+            ctx.name = name;
+            ctx.previous_name = previous_name;
+            ctx.id = std::to_string(obj->id().id);
+            ctx.index = obj_idx;
+            ctx.source = "object";
+            fire_lifecycle_event(LifecycleEvent::ObjectRenamed, ctx);
         }
         return;
     }
 
     if (volume_id < 0) return;
-    obj->volumes[volume_id]->name = m_objects_model->GetName(item).ToUTF8().data();
+    std::string name = m_objects_model->GetName(item).ToUTF8().data();
+    if (obj->volumes[volume_id]->name == name)
+        return;
+
+    const std::string previous_name = obj->volumes[volume_id]->name;
+    obj->volumes[volume_id]->name = name;
+
+    LifecycleEventContext ctx;
+    ctx.name = name;
+    ctx.previous_name = previous_name;
+    ctx.id = std::to_string(obj->volumes[volume_id]->id().id);
+    ctx.index = volume_id;
+    ctx.source = "volume";
+    fire_lifecycle_event(LifecycleEvent::ObjectRenamed, ctx);
 }
 
 void ObjectList::update_name_in_list(int obj_idx, int vol_idx) const
@@ -3519,7 +3543,14 @@ void ObjectList::delete_all_connectors_for_object(int obj_idx)
             obj->delete_connectors();
 
             if (obj->volumes.empty() || !obj->has_solid_mesh()) {
+                const std::string deleted_obj_name = obj->name;
                 model.delete_object(idx);
+                {
+                    Slic3r::LifecycleEventContext ctx;
+                    ctx.name = deleted_obj_name;
+                    ctx.code = Slic3r::LifecycleEvtCode::Ok;
+                    Slic3r::fire_lifecycle_event(Slic3r::LifecycleEvent::ObjectDeleted, ctx);
+                }
                 m_objects_model->Delete(m_objects_model->GetItemById(idx));
                 continue;
             }
@@ -4088,6 +4119,13 @@ void ObjectList::add_object_to_list(size_t obj_idx, bool call_selection_changed,
     const auto item = m_objects_model->AddObject(model_object, warning_bitmap, model_object->is_cut());
     Expand(m_objects_model->GetParent(item));
 
+    {
+        Slic3r::LifecycleEventContext ctx;
+        ctx.name = model_object->name;
+        ctx.code = Slic3r::LifecycleEvtCode::Ok;
+        Slic3r::fire_lifecycle_event(Slic3r::LifecycleEvent::ObjectAdded, ctx);
+    }
+
     if (!do_info_update)
         return;
 
diff --git a/src/slic3r/GUI/Jobs/ArrangeJob.cpp b/src/slic3r/GUI/Jobs/ArrangeJob.cpp
index c0cc7bdb5a..438bda2cc2 100644
--- a/src/slic3r/GUI/Jobs/ArrangeJob.cpp
+++ b/src/slic3r/GUI/Jobs/ArrangeJob.cpp
@@ -13,6 +13,7 @@
 #include "slic3r/GUI/NotificationManager.hpp"
 #include "slic3r/GUI/format.hpp"
 #include "slic3r/GUI/GUI_ObjectList.hpp"
+#include "slic3r/plugin/PluginManager.hpp"
 
 #include "libnest2d/common.hpp"
 
@@ -698,6 +699,13 @@ void ArrangeJob::finalize(bool canceled, std::exception_ptr &eptr) {
         BOOST_LOG_TRIVIAL(debug) << __FUNCTION__ << boost::format(":arrange m_unprintable: name: %4%, bed_id %1%, trans {%2%,%3%}") % ap.bed_idx % unscale<double>(ap.translation(X)) % unscale<double>(ap.translation(Y)) % ap.name;
     }
 
+    {
+        Slic3r::LifecycleEventContext ctx;
+        ctx.code = Slic3r::LifecycleEvtCode::Ok;
+        ctx.msg = "arranged";
+        Slic3r::fire_lifecycle_event(Slic3r::LifecycleEvent::ObjectTransformed, ctx);
+    }
+
     m_plater->update();
     // BBS
     //wxGetApp().obj_manipul()->set_dirty();
diff --git a/src/slic3r/GUI/Jobs/FillBedJob.cpp b/src/slic3r/GUI/Jobs/FillBedJob.cpp
index 5364cb5648..961b8af566 100644
--- a/src/slic3r/GUI/Jobs/FillBedJob.cpp
+++ b/src/slic3r/GUI/Jobs/FillBedJob.cpp
@@ -6,6 +6,7 @@
 #include "slic3r/GUI/Plater.hpp"
 #include "slic3r/GUI/GLCanvas3D.hpp"
 #include "slic3r/GUI/GUI_ObjectList.hpp"
+#include "slic3r/plugin/PluginManager.hpp"
 #include "libnest2d/common.hpp"
 
 #include <numeric>
@@ -347,6 +348,13 @@ void FillBedJob::finalize(bool canceled, std::exception_ptr &eptr)
             m_plater->arrange();
         }
         m_plater->update();
+
+        {
+            Slic3r::LifecycleEventContext ctx;
+            ctx.code = Slic3r::LifecycleEvtCode::Ok;
+            ctx.msg = "arranged";
+            Slic3r::fire_lifecycle_event(Slic3r::LifecycleEvent::ObjectTransformed, ctx);
+        }
     }
 
     m_plater->mark_plate_toolbar_image_dirty();
diff --git a/src/slic3r/GUI/Jobs/OrientJob.cpp b/src/slic3r/GUI/Jobs/OrientJob.cpp
index ee8ea875c0..ed9117e8bf 100644
--- a/src/slic3r/GUI/Jobs/OrientJob.cpp
+++ b/src/slic3r/GUI/Jobs/OrientJob.cpp
@@ -5,6 +5,7 @@
 #include "slic3r/GUI/GUI.hpp"
 #include "slic3r/GUI/GUI_App.hpp"
 #include "slic3r/GUI/NotificationManager.hpp"
+#include "slic3r/plugin/PluginManager.hpp"
 #include "libslic3r/PresetBundle.hpp"
 
 
@@ -254,6 +255,12 @@ void OrientJob::finalize(bool canceled, std::exception_ptr &eptr)
         mesh.apply();
     }
 
+    if (!m_selected.empty()) {
+        Slic3r::LifecycleEventContext ctx;
+        ctx.code = Slic3r::LifecycleEvtCode::Ok;
+        ctx.msg = "auto_oriented";
+        Slic3r::fire_lifecycle_event(Slic3r::LifecycleEvent::ObjectTransformed, ctx);
+    }
 
     m_plater->update();
 
diff --git a/src/slic3r/GUI/Jobs/PrintJob.cpp b/src/slic3r/GUI/Jobs/PrintJob.cpp
index dae05494e3..76e45eb1d7 100644
--- a/src/slic3r/GUI/Jobs/PrintJob.cpp
+++ b/src/slic3r/GUI/Jobs/PrintJob.cpp
@@ -1,4 +1,5 @@
 #include "PrintJob.hpp"
+#include "libslic3r/LifecycleEvents.hpp"
 #include "libslic3r/MTUtils.hpp"
 #include "libslic3r/Model.hpp"
 #include "libslic3r/PresetBundle.hpp"
@@ -152,6 +153,18 @@ void PrintJob::process(Ctl &ctl)
     int result = -1;
     std::string http_body;
 
+    const auto mark_lifecycle_started = [this]() {
+        if (m_lifecycle_started)
+            return;
+
+        LifecycleEventContext start_ctx;
+        start_ctx.name = m_project_name;
+        start_ctx.device_id = m_dev_id;
+        start_ctx.source = "print_job";
+        fire_lifecycle_event(LifecycleEvent::PrintJobStarted, start_ctx);
+        m_lifecycle_started = true;
+    };
+
     int total_plate_num = plate_data.plate_count;
     if (!plate_data.is_valid) {
         total_plate_num =  m_plater->get_partplate_list().get_plate_count();
@@ -173,7 +186,7 @@ void PrintJob::process(Ctl &ctl)
         }
     }
 
-    m_project_name = truncate_string(m_project_name, 100);
+    const std::string transport_project_name = truncate_string(m_project_name, 100);
     int curr_plate_idx = 0;
 
     if (m_print_type == "from_normal") {
@@ -372,11 +385,11 @@ void PrintJob::process(Ctl &ctl)
         }
     }
 
-    if (params.preset_name.empty() && m_print_type == "from_normal") { params.preset_name = wxString::Format("%s_plate_%d", m_project_name, curr_plate_idx).ToStdString(); }
-    if (params.project_name.empty()) {params.project_name = m_project_name;}
+    if (params.preset_name.empty() && m_print_type == "from_normal") { params.preset_name = wxString::Format("%s_plate_%d", transport_project_name, curr_plate_idx).ToStdString(); }
+    if (params.project_name.empty()) {params.project_name = transport_project_name;}
 
     if (m_is_calibration_task) {
-        params.project_name = m_project_name;
+        params.project_name = transport_project_name;
         params.origin_model_id = "";
     }
 
@@ -543,6 +556,7 @@ void PrintJob::process(Ctl &ctl)
     if (m_print_type == "from_sdcard_view") {
         BOOST_LOG_TRIVIAL(info) << "print_job: try to send with cloud, model is sdcard view";
         ctl.update_status(curr_percent, _u8L("Sending print job through cloud service"));
+        mark_lifecycle_started();
         result = m_agent->start_sdcard_print(params, update_fn, cancel_fn);
     } else if (params.connection_type != "lan") {
         if (params.dev_ip.empty())
@@ -566,6 +580,7 @@ void PrintJob::process(Ctl &ctl)
                 BOOST_LOG_TRIVIAL(info) << "print_job: use ftp send print only";
                 ctl.update_status(curr_percent, _u8L("Sending print job over LAN"));
                 is_try_lan_mode = true;
+                mark_lifecycle_started();
                 result = m_agent->start_local_print_with_record(params, update_fn, cancel_fn, wait_fn);
                 if (result < 0) {
                     error_text = wxString::Format(_L("Access code:%s IP address:%s"), params.password, params.dev_ip);
@@ -582,6 +597,7 @@ void PrintJob::process(Ctl &ctl)
                 // try to send local with record
                 BOOST_LOG_TRIVIAL(info) << "print_job: try to start local print with record";
                 ctl.update_status(curr_percent, _u8L("Sending print job over LAN"));
+                mark_lifecycle_started();
                 result = m_agent->start_local_print_with_record(params, update_fn, cancel_fn, wait_fn);
                 if (result == 0) {
                     params.comments = "";
@@ -597,18 +613,21 @@ void PrintJob::process(Ctl &ctl)
                     // try to send with cloud
                     BOOST_LOG_TRIVIAL(warning) << "print_job: try to send with cloud";
                     ctl.update_status(curr_percent, _u8L("Sending print job through cloud service"));
+                    // Started was already emitted before the local attempt.
                     result = m_agent->start_print(params, update_fn, cancel_fn, wait_fn);
                 }
             }
             else {
                 BOOST_LOG_TRIVIAL(info) << "print_job: send with cloud";
                 ctl.update_status(curr_percent, _u8L("Sending print job through cloud service"));
+                mark_lifecycle_started();
                 result = m_agent->start_print(params, update_fn, cancel_fn, wait_fn);
             }
         }
     } else {
         if (this->could_emmc_print) {
             ctl.update_status(curr_percent, _u8L("Sending print job over LAN"));
+            mark_lifecycle_started();
             result = m_agent->start_local_print(params, update_fn, cancel_fn);
         } else {
             switch(this->sdcard_state) {
@@ -619,6 +638,7 @@ void PrintJob::process(Ctl &ctl)
                     if(this->has_sdcard) {
                         // means the storage is abnormal but can be used option is enabled
                         ctl.update_status(curr_percent, _u8L("Sending print job over LAN, but the Storage in the printer is abnormal and print-issues may be caused by this."));
+                        mark_lifecycle_started();
                         result = m_agent->start_local_print(params, update_fn, cancel_fn);
                         break;
                     }
@@ -629,6 +649,7 @@ void PrintJob::process(Ctl &ctl)
                     return;
                 case DevStorage::SdcardState::HAS_SDCARD_NORMAL:
                     ctl.update_status(curr_percent, _u8L("Sending print job over LAN"));
+                    mark_lifecycle_started();
                     result = m_agent->start_local_print(params, update_fn, cancel_fn);
                     break;
                 default:
@@ -686,6 +707,7 @@ void PrintJob::process(Ctl &ctl)
         }
         wxQueueEvent(m_plater, evt);
         m_job_finished = true;
+        m_lifecycle_success = true;
     }
 }
 
@@ -698,6 +720,19 @@ void PrintJob::finalize(bool canceled, std::exception_ptr &eptr) {
         eptr = std::current_exception();
     }
 
+    if (m_lifecycle_started && !m_lifecycle_finished) {
+        LifecycleEventContext finish_ctx;
+        finish_ctx.name = m_project_name;
+        finish_ctx.device_id = m_dev_id;
+        finish_ctx.source = "print_job";
+        finish_ctx.code = canceled ? LifecycleEvtCode::Warn :
+            (eptr || !m_lifecycle_success ? LifecycleEvtCode::Error : LifecycleEvtCode::Ok);
+        finish_ctx.msg = canceled ? "cancelled" : (eptr ? "exception" :
+            (m_lifecycle_success ? "" : "failed"));
+        fire_lifecycle_event(LifecycleEvent::PrintJobFinished, finish_ctx);
+        m_lifecycle_finished = true;
+    }
+
     if (canceled || eptr)
         return;
 }
diff --git a/src/slic3r/GUI/Jobs/PrintJob.hpp b/src/slic3r/GUI/Jobs/PrintJob.hpp
index 9a23b04054..4be68031d9 100644
--- a/src/slic3r/GUI/Jobs/PrintJob.hpp
+++ b/src/slic3r/GUI/Jobs/PrintJob.hpp
@@ -43,6 +43,9 @@ class PrintJob : public Job
     std::function<void()> m_success_fun{nullptr};
     std::string         m_dev_id;
     bool                m_job_finished{ false };
+    bool                m_lifecycle_started{ false };
+    bool                m_lifecycle_finished{ false };
+    bool                m_lifecycle_success{ false };
     int                 m_print_job_completed_id = 0;
     wxString            m_completed_evt_data;
     std::function<void()> m_enter_ip_address_fun_fail{ nullptr };
diff --git a/src/slic3r/GUI/Jobs/SendJob.cpp b/src/slic3r/GUI/Jobs/SendJob.cpp
index d27b18f24b..505475e4a9 100644
--- a/src/slic3r/GUI/Jobs/SendJob.cpp
+++ b/src/slic3r/GUI/Jobs/SendJob.cpp
@@ -1,4 +1,5 @@
 #include "SendJob.hpp"
+#include "libslic3r/LifecycleEvents.hpp"
 #include "slic3r/GUI/I18N.hpp"
 #include "slic3r/Utils/NetworkAgent.hpp"
 #include "libslic3r/MTUtils.hpp"
@@ -148,6 +149,13 @@ void SendJob::process(Ctl &ctl)
         }
     }
 
+    LifecycleEventContext start_ctx;
+    start_ctx.name = m_project_name;
+    start_ctx.device_id = m_dev_id;
+    start_ctx.source = "send_job";
+    fire_lifecycle_event(LifecycleEvent::SendJobStarted, start_ctx);
+    m_lifecycle_started = true;
+
     int total_plate_num = m_plater->get_partplate_list().get_plate_count();
 
     PartPlate* plate = m_plater->get_partplate_list().get_plate(job_data.plate_idx);
@@ -424,6 +432,19 @@ void SendJob::finalize(bool canceled, std::exception_ptr &eptr)
         eptr = std::current_exception();
     }
 
+    if (m_lifecycle_started && !m_lifecycle_finished) {
+        LifecycleEventContext finish_ctx;
+        finish_ctx.name = m_project_name;
+        finish_ctx.device_id = m_dev_id;
+        finish_ctx.source = "send_job";
+        finish_ctx.code = canceled ? LifecycleEvtCode::Warn :
+            (eptr ? LifecycleEvtCode::Error : (m_job_finished ? LifecycleEvtCode::Ok : LifecycleEvtCode::Error));
+        finish_ctx.msg = canceled ? "cancelled" : (eptr ? "exception" :
+            (m_job_finished ? "" : "failed"));
+        fire_lifecycle_event(LifecycleEvent::SendJobFinished, finish_ctx);
+        m_lifecycle_finished = true;
+    }
+
     if (canceled || eptr)
         return;
 }
diff --git a/src/slic3r/GUI/Jobs/SendJob.hpp b/src/slic3r/GUI/Jobs/SendJob.hpp
index 1d4e025d6e..86d180ac8c 100644
--- a/src/slic3r/GUI/Jobs/SendJob.hpp
+++ b/src/slic3r/GUI/Jobs/SendJob.hpp
@@ -22,6 +22,8 @@ class SendJob : public Job
     PrintPrepareData    job_data;
     std::string         m_dev_id;
     bool                m_job_finished{ false };
+    bool                m_lifecycle_started{ false };
+    bool                m_lifecycle_finished{ false };
     int                 m_print_job_completed_id = 0;
     bool                m_is_check_mode{false};
     bool                m_check_and_continue{false};
diff --git a/src/slic3r/GUI/PartPlate.cpp b/src/slic3r/GUI/PartPlate.cpp
index 428f45c845..3493506228 100644
--- a/src/slic3r/GUI/PartPlate.cpp
+++ b/src/slic3r/GUI/PartPlate.cpp
@@ -29,6 +29,7 @@
 #include "libslic3r/Tesselate.hpp"
 #include "libslic3r/GCode/ThumbnailData.hpp"
 #include "libslic3r/Utils.hpp"
+#include "libslic3r/LifecycleEvents.hpp"
 
 #include "I18N.hpp"
 #include "GUI_App.hpp"
@@ -2626,11 +2627,20 @@ void PartPlate::set_plate_name(const std::string& name)
     if (boost::equals(m_name, name))
         return;
 
+	const std::string previous_name = m_name;
 	m_name = name;
     if (m_print != nullptr)
         m_print->set_plate_name(name);
 
 	invalidate_plate_name_texture();
+
+    if (m_plater != nullptr && !m_plater->is_loading_project()) {
+        LifecycleEventContext ctx;
+        ctx.name = name;
+        ctx.previous_name = previous_name;
+        ctx.index = m_plate_index;
+        fire_lifecycle_event(LifecycleEvent::PlateRenamed, ctx);
+    }
 }
 
 //get the print's object, result and index
@@ -4741,9 +4751,16 @@ int PartPlateList::create_plate(bool adjust_position)
 
 	if (m_plater) {
 		// In GUI mode
-		wxGetApp().obj_list()->on_plate_added(plate);
+        wxGetApp().obj_list()->on_plate_added(plate);
 	}
 
+    if (m_plater != nullptr && m_intialized && !m_plater->is_loading_project()) {
+        LifecycleEventContext ctx;
+        ctx.name = plate->get_plate_name();
+        ctx.index = new_index;
+        fire_lifecycle_event(LifecycleEvent::PlateCreated, ctx);
+    }
+
 	BOOST_LOG_TRIVIAL(debug) << __FUNCTION__ << boost::format(":created a new plate %1%") % new_index;
 	return new_index;
 }
@@ -4842,6 +4859,7 @@ int PartPlateList::delete_plate(int index)
 		BOOST_LOG_TRIVIAL(warning) << __FUNCTION__ << boost::format(":plate %1%, has an invalid index %2%") % index % plate->get_index();
 		return -1;
 	}
+	const std::string plate_name = plate->get_plate_name();
 
 	if (m_plater) {
 		// In GUI mode
@@ -4924,6 +4942,13 @@ int PartPlateList::delete_plate(int index)
 
 	delete plate;
 
+    if (m_plater != nullptr && m_intialized && !m_plater->is_loading_project()) {
+        LifecycleEventContext ctx;
+        ctx.name = plate_name;
+        ctx.index = index;
+        fire_lifecycle_event(LifecycleEvent::PlateDeleted, ctx);
+    }
+
     // FIX: context of BackgroundSliceProcess and gcode preview need to be updated before ObjectList::reload_all_plates().
 #if 0
 	if (m_plater != nullptr) {
@@ -5032,6 +5057,7 @@ int PartPlateList::select_plate(int index)
 	if (m_plate_list.empty() || index >= m_plate_list.size()) {
 		return -1;
 	}
+	const int previous_index = m_current_plate;
 
 	// BBS: erase unnecessary snapshot
 	if (get_curr_plate_index() != index && m_intialized) {
@@ -5058,6 +5084,13 @@ int PartPlateList::select_plate(int index)
 		//wxQueueEvent(m_plater, new SimpleEvent(EVT_GLCANVAS_PLATE_SELECT));
 	}
 
+    if (previous_index != index && m_intialized && m_plater != nullptr && !m_plater->is_loading_project()) {
+        LifecycleEventContext ctx;
+        ctx.name = m_plate_list[index]->get_plate_name();
+        ctx.index = index;
+        fire_lifecycle_event(LifecycleEvent::PlateSelected, ctx);
+    }
+
 	return 0;
 }
 
diff --git a/src/slic3r/GUI/Plater.cpp b/src/slic3r/GUI/Plater.cpp
index 76156011dd..d4386fbe93 100644
--- a/src/slic3r/GUI/Plater.cpp
+++ b/src/slic3r/GUI/Plater.cpp
@@ -57,6 +57,7 @@
 #include <wx/aui/aui.h>
 
 #include "libslic3r/libslic3r.h"
+#include "libslic3r/LifecycleEvents.hpp"
 #include "libslic3r/Format/STL.hpp"
 #include "libslic3r/Format/DRC.hpp"
 #include "libslic3r/Format/STEP.hpp"
@@ -10264,7 +10265,14 @@ void Plater::priv::remove(size_t obj_idx)
         view3D->enable_layers_editing(false);
 
     m_worker.cancel_all();
+    std::string obj_name = (obj_idx < model.objects.size()) ? model.objects[obj_idx]->name : std::to_string(obj_idx);
     model.delete_object(obj_idx);
+    {
+        Slic3r::LifecycleEventContext ctx;
+        ctx.name = obj_name;
+        ctx.code = Slic3r::LifecycleEvtCode::Ok;
+        Slic3r::fire_lifecycle_event(Slic3r::LifecycleEvent::ObjectDeleted, ctx);
+    }
     //BBS: notify partplate the instance removed
     partplate_list.notify_instance_removed(obj_idx, -1);
     update();
@@ -10297,7 +10305,14 @@ bool Plater::priv::delete_object_from_model(size_t obj_idx, bool refresh_immedia
     if (obj->is_cut())
         sidebar->obj_list()->invalidate_cut_info_for_object(obj_idx);
 
+    std::string obj_name = obj->name;
     model.delete_object(obj_idx);
+    {
+        Slic3r::LifecycleEventContext ctx;
+        ctx.name = obj_name;
+        ctx.code = Slic3r::LifecycleEvtCode::Ok;
+        Slic3r::fire_lifecycle_event(Slic3r::LifecycleEvent::ObjectDeleted, ctx);
+    }
     //BBS: notify partplate the instance removed
     partplate_list.notify_instance_removed(obj_idx, -1);
 
@@ -10343,10 +10358,22 @@ void Plater::priv::delete_all_objects_from_model()
 
 void Plater::priv::reset(bool apply_presets_change)
 {
+    // TakeSnapshot below and load_current_presets() further down each re-evaluate the
+    // aggregate dirty flag against a baseline that hasn't been reset yet, so they can toggle
+    // is_dirty() back and forth several times before it settles; coalesce those into one event.
+    ProjectDirtyStateManager::NotificationSuppressor dirty_notify_suppressor(dirty_state);
+
     Plater::TakeSnapshot snapshot(q, _u8L("Reset Project"), UndoRedo::SnapshotType::ProjectSeparator);
 
     clear_warnings();
 
+    const std::string closed_project_name = into_u8(get_project_filename());
+    if (!closed_project_name.empty() || !model.objects.empty()) {
+        Slic3r::LifecycleEventContext ctx;
+        ctx.name = closed_project_name;
+        ctx.code = Slic3r::LifecycleEvtCode::Ok;
+        Slic3r::fire_lifecycle_event(Slic3r::LifecycleEvent::ProjectClosed, ctx);
+    }
     // A new project must not inherit the previous project's published selection (Feature A/B).
     m_has_pending_published   = false;
     m_pending_published_keys.clear();
@@ -12774,11 +12801,15 @@ void Plater::priv::on_process_completed(SlicingProcessCompletedEvent &evt)
     notification_manager->set_slicing_progress_export_possible();
 
     // Reset the "export G-code path" name, so that the automatic background processing will be enabled again.
+    const std::string lifecycle_job_name = this->background_process.fff_print() ?
+        this->background_process.fff_print()->output_filename() : std::string();
     this->background_process.reset_export();
     // This bool stops showing export finished notification even when process_completed_with_error is false
     bool has_error = false;
+    std::string lifecycle_error_msg;
     if (evt.error()) {
         auto message = evt.format_error_message();
+        lifecycle_error_msg = message.first;
         if (evt.critical_error()) {
             if (q->m_tracking_popup_menu) {
                 // We don't want to pop-up a message box when tracking a pop-up menu.
@@ -12816,6 +12847,14 @@ void Plater::priv::on_process_completed(SlicingProcessCompletedEvent &evt)
         is_finished = true;
     }
 
+    {
+        Slic3r::LifecycleEventContext ctx;
+        ctx.name = lifecycle_job_name;
+        ctx.code = evt.cancelled() ? Slic3r::LifecycleEvtCode::Warn : (has_error ? Slic3r::LifecycleEvtCode::Error : Slic3r::LifecycleEvtCode::Ok);
+        ctx.msg  = evt.cancelled() ? "cancelled" : (has_error ? lifecycle_error_msg : std::string());
+        Slic3r::fire_lifecycle_event(Slic3r::LifecycleEvent::SlicingJobComplete, ctx);
+    }
+
     //BBS: set the current plater's slice result to valid
     if (!this->background_process.empty())
         this->background_process.get_current_plate()->update_slice_result_valid_state(evt.success());
@@ -15349,21 +15388,33 @@ int Plater::new_project(bool skip_confirm, bool silent, const wxString& project_
     //get_partplate_list().reinit();
     //get_partplate_list().update_slice_context_to_current_plate(p->background_process);
     //p->preview->update_gcode_result(p->partplate_list.get_current_slice_result());
-    reset(transfer_preset_changes);
-    reset_project_dirty_after_save();
-    reset_project_dirty_initial_presets();
-    wxGetApp().update_saved_preset_from_current_preset();
-    update_project_dirty_from_presets();
+    if (!silent) {
+        Slic3r::LifecycleEventContext ctx;
+        ctx.code = Slic3r::LifecycleEvtCode::Ok;
+        Slic3r::fire_lifecycle_event(Slic3r::LifecycleEvent::NewProject, ctx);
+    }
+    {
+        // Same rationale as in Plater::priv::reset(): the whole reset + preset-reload +
+        // baseline-reset sequence below settles into its final dirty state only once it
+        // completes, so hold notifications until then to avoid firing on transient flips.
+        ProjectDirtyStateManager::NotificationSuppressor dirty_notify_suppressor(p->dirty_state);
 
-    //reset project
-    p->project.reset();
-    //set project name
-    if (project_name.empty())
-        p->set_project_name(_L("Untitled"));
-    else
-        p->set_project_name(project_name);
+        reset(transfer_preset_changes);
+        reset_project_dirty_after_save();
+        reset_project_dirty_initial_presets();
+        wxGetApp().update_saved_preset_from_current_preset();
+        update_project_dirty_from_presets();
 
-    Plater::TakeSnapshot snapshot(this, "New Project", UndoRedo::SnapshotType::ProjectSeparator);
+        //reset project
+        p->project.reset();
+        //set project name
+        if (project_name.empty())
+            p->set_project_name(_L("Untitled"));
+        else
+            p->set_project_name(project_name);
+
+        Plater::TakeSnapshot snapshot(this, "New Project", UndoRedo::SnapshotType::ProjectSeparator);
+    }
 
     Model m;
     model().load_from(m); // new id avoid same path name
@@ -15481,6 +15532,13 @@ void Plater::load_project(wxString const& filename2,
         p->set_project_name(_L("Untitled"));
         }
 
+        {
+            Slic3r::LifecycleEventContext ctx;
+            ctx.name = into_u8(load_restore ? originfile : filename);
+            ctx.code = Slic3r::LifecycleEvtCode::Ok;
+            Slic3r::fire_lifecycle_event(Slic3r::LifecycleEvent::ProjectOpened, ctx);
+        }
+
     } else {
         if (using_exported_file()) {
             BOOST_LOG_TRIVIAL(info) << __FUNCTION__ << __LINE__ << " using ecported set project filename: " << filename;
@@ -15552,11 +15610,23 @@ int Plater::save_project(bool saveAs)
     if (full_pathnames) {
         save_strategy = save_strategy | SaveStrategy::FullPathSources;
     }
+    {
+        Slic3r::LifecycleEventContext ctx;
+        ctx.name = into_u8(filename);
+        ctx.code = Slic3r::LifecycleEvtCode::Ok;
+        Slic3r::fire_lifecycle_event(Slic3r::LifecycleEvent::ProjectBeforeSave, ctx);
+    }
     if (export_3mf(into_path(filename), save_strategy) < 0) {
         MessageDialog(this, _L("Failed to save the project.\nPlease check whether the folder exists online or if other programs have the project file open."),
             _L("Save project"), wxOK | wxICON_WARNING).ShowModal();
         return wxID_CANCEL;
     }
+    {
+        Slic3r::LifecycleEventContext ctx;
+        ctx.name = into_u8(filename);
+        ctx.code = Slic3r::LifecycleEvtCode::Ok;
+        Slic3r::fire_lifecycle_event(Slic3r::LifecycleEvent::ProjectAfterSave, ctx);
+    }
 
     Slic3r::remove_backup(model(), false);
 
@@ -20889,6 +20959,14 @@ void Plater::changed_object(ModelObject &object){
         
     // Check outside bed
     get_current_canvas3D()->requires_check_outside_state();
+
+    if (!is_loading_project()) {
+        LifecycleEventContext ctx;
+        ctx.name = object.name;
+        ctx.id = std::to_string(object.id().id);
+        ctx.source = "geometry";
+        fire_lifecycle_event(LifecycleEvent::ObjectChanged, ctx);
+    }
 }
 
 void Plater::changed_object(int obj_idx)
@@ -20925,6 +21003,20 @@ void Plater::changed_objects(const std::vector<size_t>& object_idxs)
 
     // update print
     this->p->schedule_background_process();
+
+    if (!is_loading_project()) {
+        for (size_t obj_idx : object_idxs) {
+            if (obj_idx >= p->model.objects.size() || p->model.objects[obj_idx] == nullptr)
+                continue;
+
+            LifecycleEventContext ctx;
+            ctx.name = p->model.objects[obj_idx]->name;
+            ctx.id = std::to_string(p->model.objects[obj_idx]->id().id);
+            ctx.index = static_cast<int>(obj_idx);
+            ctx.source = "geometry";
+            fire_lifecycle_event(LifecycleEvent::ObjectChanged, ctx);
+        }
+    }
 }
 
 void Plater::schedule_background_process(bool schedule/* = true*/)
diff --git a/src/slic3r/GUI/ProjectDirtyStateManager.cpp b/src/slic3r/GUI/ProjectDirtyStateManager.cpp
index c986328f71..53eb3cd353 100644
--- a/src/slic3r/GUI/ProjectDirtyStateManager.cpp
+++ b/src/slic3r/GUI/ProjectDirtyStateManager.cpp
@@ -6,6 +6,7 @@
 #include "MainFrame.hpp"
 #include "I18N.hpp"
 #include "Plater.hpp"
+#include "libslic3r/LifecycleEvents.hpp"
 
 #include <boost/algorithm/string/predicate.hpp>
 
@@ -17,13 +18,23 @@ namespace GUI {
 
 void ProjectDirtyStateManager::update_from_undo_redo_stack(bool dirty)
 {
+    const bool was_dirty = is_dirty();
     m_plater_dirty = dirty;
+    notify_dirty_change(was_dirty, "undo_redo");
     if (const Plater *plater = wxGetApp().plater(); plater && wxGetApp().initialized())
         wxGetApp().mainframe->update_title();
 }
 
+void ProjectDirtyStateManager::set_plater_dirty(bool is_dirty)
+{
+    const bool was_dirty = this->is_dirty();
+    m_plater_dirty = is_dirty;
+    notify_dirty_change(was_dirty, "plater");
+}
+
 void ProjectDirtyStateManager::update_from_presets()
 {
+    const bool was_dirty = is_dirty();
     m_presets_dirty = false;
     // check switching of the presets only for exist/loaded project, but not for new
     GUI_App &app = wxGetApp();
@@ -45,18 +56,53 @@ void ProjectDirtyStateManager::update_from_presets()
     }
     m_presets_dirty |= app.has_unsaved_preset_changes();
     m_project_config_dirty = m_initial_project_config != app.preset_bundle->project_config;
+    notify_dirty_change(was_dirty, "presets");
     app.mainframe->update_title();
 }
 
 void ProjectDirtyStateManager::reset_after_save()
 {
+    const bool was_dirty = is_dirty();
     this->reset_initial_presets();
     m_plater_dirty  = false;
     m_presets_dirty = false;
     m_project_config_dirty = false;
+    notify_dirty_change(was_dirty, "save");
     wxGetApp().mainframe->update_title();
 }
 
+void ProjectDirtyStateManager::notify_dirty_change(bool was_dirty, const char *source)
+{
+    if (m_suppress_depth > 0)
+        return;
+
+    const bool dirty = is_dirty();
+    if (was_dirty == dirty)
+        return;
+
+    LifecycleEventContext ctx;
+    ctx.code = LifecycleEvtCode::Ok;
+    ctx.dirty = dirty;
+    ctx.source = source;
+    fire_lifecycle_event(LifecycleEvent::ProjectDirtyChanged, ctx);
+}
+
+void ProjectDirtyStateManager::begin_suppress_notifications()
+{
+    if (m_suppress_depth == 0)
+        m_suppress_entry_dirty = is_dirty();
+    ++m_suppress_depth;
+}
+
+void ProjectDirtyStateManager::end_suppress_notifications()
+{
+    assert(m_suppress_depth > 0);
+    if (m_suppress_depth > 0)
+        --m_suppress_depth;
+    if (m_suppress_depth == 0)
+        notify_dirty_change(m_suppress_entry_dirty, "batch");
+}
+
 void ProjectDirtyStateManager::reset_initial_presets()
 {
     m_initial_presets.fill(std::string{});
@@ -168,4 +214,3 @@ void ProjectDirtyStateManager::render_debug_window() const
 
 } // namespace GUI
 } // namespace Slic3r
-
diff --git a/src/slic3r/GUI/ProjectDirtyStateManager.hpp b/src/slic3r/GUI/ProjectDirtyStateManager.hpp
index 171d19e219..fd121d1d85 100644
--- a/src/slic3r/GUI/ProjectDirtyStateManager.hpp
+++ b/src/slic3r/GUI/ProjectDirtyStateManager.hpp
@@ -14,21 +14,42 @@ public:
     void reset_after_save();
     void reset_initial_presets();
 
-    void set_plater_dirty(bool is_dirty) { m_plater_dirty = is_dirty; }
+    void set_plater_dirty(bool is_dirty);
     bool is_dirty() const { return m_plater_dirty || m_project_config_dirty || m_presets_dirty; }
     bool is_presets_dirty() const { return m_presets_dirty; }
 
+    // RAII guard coalescing dirty-state updates: while any guard is alive, ProjectDirtyChanged
+    // notifications are held back; when the outermost guard is destroyed, at most one
+    // notification fires, reflecting only the net change across the whole guarded scope.
+    class NotificationSuppressor
+    {
+    public:
+        explicit NotificationSuppressor(ProjectDirtyStateManager &owner) : m_owner(owner) { m_owner.begin_suppress_notifications(); }
+        ~NotificationSuppressor() { m_owner.end_suppress_notifications(); }
+        NotificationSuppressor(const NotificationSuppressor &) = delete;
+        NotificationSuppressor &operator=(const NotificationSuppressor &) = delete;
+    private:
+        ProjectDirtyStateManager &m_owner;
+    };
+
 #if ENABLE_PROJECT_DIRTY_STATE_DEBUG_WINDOW
     void render_debug_window() const;
 #endif // ENABLE_PROJECT_DIRTY_STATE_DEBUG_WINDOW
 
 private:
+    void notify_dirty_change(bool was_dirty, const char *source);
+    void begin_suppress_notifications();
+    void end_suppress_notifications();
+
     // Does the Undo / Redo stack indicate the project is dirty?
     bool                                        m_plater_dirty { false };
     // Do the presets indicate the project is dirty?
     bool                                        m_presets_dirty { false };
     // Is the project config dirty?
     bool                                        m_project_config_dirty { false };
+    // NotificationSuppressor nesting depth and the dirty state observed when the outermost guard began.
+    int                                          m_suppress_depth { 0 };
+    bool                                         m_suppress_entry_dirty { false };
     // Keeps track of preset names selected at the time of last project save.
     std::array<std::string, Preset::TYPE_COUNT> m_initial_presets;
     DynamicPrintConfig                          m_initial_project_config;
diff --git a/src/slic3r/GUI/Tab.cpp b/src/slic3r/GUI/Tab.cpp
index f6c1cbf901..1312d0e11d 100644
--- a/src/slic3r/GUI/Tab.cpp
+++ b/src/slic3r/GUI/Tab.cpp
@@ -38,6 +38,7 @@
 #include "slic3r/Utils/NetworkAgentFactory.hpp"
 #include "slic3r/Utils/PresetUpdater.hpp"
 #include "slic3r/plugin/PluginConfig.hpp"
+#include "slic3r/plugin/PluginManager.hpp"
 #include "Plater.hpp"
 #include "MainFrame.hpp"
 #include "format.hpp"
@@ -6964,6 +6965,20 @@ bool Tab::select_preset(
         }
         load_current_preset();
 
+        {
+            Slic3r::LifecycleEventContext ctx;
+            ctx.name = preset_name;
+            ctx.code = Slic3r::LifecycleEvtCode::Ok;
+            switch (m_type) {
+            case Preset::TYPE_PRINT:        ctx.msg = "print"; break;
+            case Preset::TYPE_SLA_PRINT:    ctx.msg = "sla_print"; break;
+            case Preset::TYPE_FILAMENT:     ctx.msg = "filament"; break;
+            case Preset::TYPE_SLA_MATERIAL: ctx.msg = "sla_material"; break;
+            case Preset::TYPE_PRINTER:      ctx.msg = "printer"; break;
+            default: break;
+            }
+            Slic3r::fire_lifecycle_event(Slic3r::LifecycleEvent::PresetSelected, ctx);
+        }
 
         if (delete_third_printer) {
             wxGetApp().CallAfter([filament_presets, process_presets]() {
diff --git a/src/slic3r/GUI/TaskManager.cpp b/src/slic3r/GUI/TaskManager.cpp
index d294d140c5..64f3e5d6a5 100644
--- a/src/slic3r/GUI/TaskManager.cpp
+++ b/src/slic3r/GUI/TaskManager.cpp
@@ -1,10 +1,13 @@
 #include "TaskManager.hpp"
 
 #include "libslic3r/Thread.hpp"
+#include "libslic3r/LifecycleEvents.hpp"
 #include "nlohmann/json.hpp"
 #include "MainFrame.hpp"
 #include "GUI_App.hpp"
 
+#include <exception>
+
 using namespace nlohmann;
 
 namespace Slic3r {
@@ -214,17 +217,34 @@ int TaskManager::schedule(TaskStateInfo* task)
     boost::thread* new_sending_thread = new boost::thread();
     *new_sending_thread = Slic3r::create_thread(
         [this, task] {
+            // Keep both lifecycle callbacks on this per-task worker thread. Plugin observers can
+            // therefore associate Started and Finished for one task with a single execution context.
+            LifecycleEventContext start_ctx;
+            start_ctx.name = task->params().project_name;
+            start_ctx.device_id = task->params().dev_id;
+            start_ctx.job_id = std::to_string(task->task_info_id);
+            start_ctx.source = "task_manager";
+            fire_lifecycle_event(LifecycleEvent::PrintJobStarted, start_ctx);
+
+            int result = -1;
             if (!m_agent) {
                 BOOST_LOG_TRIVIAL(trace) << "task_manager: NetworkAgent is nullptr";
-                return;
             }
-            assert(m_agent);
+            else {
+                assert(m_agent);
+                try {
 // DEBUG FOR TEST
 #if 0
-            int result = start_print_test(task->get_params(), task->update_status_fn, task->cancel_fn, task->wait_fn);
+                    result = start_print_test(task->get_params(), task->update_status_fn, task->cancel_fn, task->wait_fn);
 #else
-            int result = m_agent->start_print(task->get_params(), task->update_status_fn, task->cancel_fn, task->wait_fn);
+                    result = m_agent->start_print(task->get_params(), task->update_status_fn, task->cancel_fn, task->wait_fn);
 #endif
+                } catch (const std::exception& ex) {
+                    BOOST_LOG_TRIVIAL(error) << "task_manager: start_print threw: " << ex.what();
+                } catch (...) {
+                    BOOST_LOG_TRIVIAL(error) << "task_manager: start_print threw an unknown exception";
+                }
+            }
             if (result == 0) {
                 last_sent_timestamp = std::chrono::system_clock::now();
                 task->set_sent_time(last_sent_timestamp);
@@ -237,6 +257,16 @@ int TaskManager::schedule(TaskStateInfo* task)
                     task->set_state(TaskState::TS_SEND_CANCELED);
                 }
             }
+
+            LifecycleEventContext finish_ctx;
+            finish_ctx.name = task->params().project_name;
+            finish_ctx.device_id = task->params().dev_id;
+            finish_ctx.job_id = std::to_string(task->task_info_id);
+            finish_ctx.source = "task_manager";
+            finish_ctx.code = result == 0 ? LifecycleEvtCode::Ok :
+                (task->is_canceled() ? LifecycleEvtCode::Warn : LifecycleEvtCode::Error);
+            finish_ctx.msg = result == 0 ? "" : (task->is_canceled() ? "cancelled" : "failed");
+            fire_lifecycle_event(LifecycleEvent::PrintJobFinished, finish_ctx);
      
             /* remove from sending task list */
             m_scedule_mutex.lock();
diff --git a/src/slic3r/Utils/PrintHost.cpp b/src/slic3r/Utils/PrintHost.cpp
index 37e0a41f83..04709fef4c 100644
--- a/src/slic3r/Utils/PrintHost.cpp
+++ b/src/slic3r/Utils/PrintHost.cpp
@@ -24,6 +24,7 @@
 #include "CrealityPrint.hpp"
 #include "../GUI/PrintHostDialogs.hpp"
 #include "../GUI/MainFrame.hpp"
+#include "slic3r/plugin/PluginManager.hpp"
 #include "Obico.hpp"
 #include "Flashforge.hpp"
 #include "SimplyPrint.hpp"
@@ -360,12 +361,29 @@ void PrintHostJobQueue::priv::perform_job(PrintHostJob the_job)
 {
     emit_progress(0);   // Indicate the upload is starting
 
+    // Captured before upload_data is moved into upload() below.
+    const std::string upload_filename = the_job.upload_data.source_path.filename().string();
+
+    {
+        LifecycleEventContext ctx;
+        ctx.name = upload_filename;
+        ctx.code = LifecycleEvtCode::Ok;
+        fire_lifecycle_event(LifecycleEvent::UploadStarted, ctx);
+    }
+
     bool success = the_job.printhost->upload(std::move(the_job.upload_data),
         [this](Http::Progress progress, bool &cancel)   { this->progress_fn(std::move(progress), cancel); },
         [this](wxString error)                          { this->error_fn(std::move(error)); },
         [this](wxString tag, wxString host)             { this->info_fn(std::move(tag), std::move(host)); }
     );
 
+    {
+        LifecycleEventContext ctx;
+        ctx.name  = upload_filename;
+        ctx.code  = success ? LifecycleEvtCode::Ok : LifecycleEvtCode::Error;
+        fire_lifecycle_event(LifecycleEvent::UploadFinished, ctx);
+    }
+
     if (success) {
         emit_progress(100);
         if (the_job.switch_to_device_tab) {
diff --git a/src/slic3r/plugin/PluginHooks.cpp b/src/slic3r/plugin/PluginHooks.cpp
index c6aaaf803c..2d84df5fdb 100644
--- a/src/slic3r/plugin/PluginHooks.cpp
+++ b/src/slic3r/plugin/PluginHooks.cpp
@@ -7,6 +7,7 @@
 
 #include "libslic3r/Config.hpp"
 #include "libslic3r/Exception.hpp"
+#include "libslic3r/LifecycleEvents.hpp"
 #include "libslic3r/Print.hpp"
 #include "libslic3r_version.h"
 
@@ -46,6 +47,16 @@ void install_capability_resolver()
     });
 }
 
+// Global libslic3r-side seam (Slic3r::fire_lifecycle_event, in libslic3r/LifecycleEvents.hpp):
+// broadcasts to every loaded, enabled capability regardless of type, unlike the SlicingPipeline
+// hook below which only targets picker-selected SlicingPipeline capabilities.
+void install_lifecycle_event_hook()
+{
+    set_lifecycle_hook_fn([](LifecycleEvent event, const LifecycleEventContext& ctx) {
+        PluginManager::instance().dispatch_lifecycle_event(event, ctx);
+    });
+}
+
 // Print::process() fires this hook at each pipeline seam on the slicing worker
 // thread; here we run the picker-selected SlicingPipeline capabilities. Per
 // capability we acquire the GIL, honor cancellation, and convert a plugin
@@ -122,12 +133,14 @@ void install()
 {
     install_capability_resolver();
     install_slicing_pipeline_hook();
+    install_lifecycle_event_hook();
 }
 
 void uninstall()
 {
     ConfigBase::set_resolve_capability_fn(nullptr);
     Print::set_slicing_pipeline_hook_fn(nullptr);
+    set_lifecycle_hook_fn(nullptr);
 }
 
 } // namespace Slic3r::plugin_hooks
diff --git a/src/slic3r/plugin/PluginHooks.hpp b/src/slic3r/plugin/PluginHooks.hpp
index bff276c5df..5eeacfa449 100644
--- a/src/slic3r/plugin/PluginHooks.hpp
+++ b/src/slic3r/plugin/PluginHooks.hpp
@@ -14,8 +14,9 @@ namespace Slic3r::plugin_hooks {
 void install();
 
 // Reset every hook to null so none can enter Python after the interpreter
-// finalizes. Called from PluginManager::shutdown(); callers must have stopped
-// background slicing first (resetting a hook while process() runs is a race).
+// finalizes. The lifecycle-event hook drains callbacks already in progress
+// before returning. Other hooks retain their existing caller-side shutdown
+// requirements.
 void uninstall();
 
 } // namespace Slic3r::plugin_hooks
diff --git a/src/slic3r/plugin/PluginManager.cpp b/src/slic3r/plugin/PluginManager.cpp
index 57bce7d2f2..022f85eb1f 100644
--- a/src/slic3r/plugin/PluginManager.cpp
+++ b/src/slic3r/plugin/PluginManager.cpp
@@ -1,5 +1,6 @@
 #include "PluginManager.hpp"
 
+#include <exception>
 #include <libslic3r/Utils.hpp>
 #include <memory>
 #include <pybind11/embed.h>
@@ -134,7 +135,8 @@ void PluginManager::shutdown()
     BOOST_LOG_TRIVIAL(info) << __FUNCTION__ << ": PluginManager shutdown enter";
 
     // Detach the libslic3r hooks first so nothing dispatches into Python while (or after) plugins
-    // unload. Callers stop background slicing before this.
+    // unload. The lifecycle-event hook also drains callbacks already in progress before returning;
+    // the remaining hook seams retain their existing shutdown requirements.
     plugin_hooks::uninstall();
 
     // Reject new plugin loads before we drain.
@@ -2089,4 +2091,33 @@ ExecutionResult PluginManager::run_script_capability(const std::string& plugin_k
     return result;
 }
 
+void PluginManager::dispatch_lifecycle_event(LifecycleEvent evt, const LifecycleEventContext& ctx) {
+    const auto is_canceled = [&ctx]() {
+        return ctx.cancellation_check && ctx.cancellation_check();
+    };
+
+    if (is_canceled())
+        return;
+
+    for (const auto& cap : get_plugin_capabilities()) {
+        if (!cap || !cap->is_enabled()) continue;
+        if (is_canceled())
+            break;
+        try {
+            cap->on_lifecycle_event(evt, ctx);
+        } catch (const std::exception& ex) {
+            BOOST_LOG_TRIVIAL(warning) << __FUNCTION__ << ": plugin '" << cap->audit_plugin_key() << "/" << cap->name()
+                                       << "' on_lifecycle_event(" << lifecycle_event_to_string(evt) << ") threw: " << ex.what()
+                                       << " [ctx name='" << ctx.name << "', code=" << lifecycle_evt_code_to_string(ctx.code)
+                                       << ", msg='" << ctx.msg << "']";
+        } catch (...) {
+            BOOST_LOG_TRIVIAL(warning) << __FUNCTION__ << ": plugin '" << cap->audit_plugin_key() << "/" << cap->name()
+                                       << "' on_lifecycle_event(" << lifecycle_event_to_string(evt)
+                                       << ") threw a non-standard exception"
+                                       << " [ctx name='" << ctx.name << "', code=" << lifecycle_evt_code_to_string(ctx.code)
+                                       << ", msg='" << ctx.msg << "']";
+        }
+    }
+}
+
 } // namespace Slic3r
diff --git a/src/slic3r/plugin/PluginManager.hpp b/src/slic3r/plugin/PluginManager.hpp
index e1fedaff94..891f787bf2 100644
--- a/src/slic3r/plugin/PluginManager.hpp
+++ b/src/slic3r/plugin/PluginManager.hpp
@@ -8,6 +8,7 @@
 #include <condition_variable>
 #include <functional>
 #include <libslic3r/Config.hpp>
+#include <libslic3r/LifecycleEvents.hpp>
 #include <map>
 #include <memory>
 #include <mutex>
@@ -20,7 +21,6 @@
 #include <pybind11/embed.h>
 
 #include "CloudPluginService.hpp"
-#include "PluginFsUtils.hpp"
 #include "PluginDescriptor.hpp"
 #include "PluginLoader.hpp"
 #include "PluginConfig.hpp"
@@ -210,6 +210,8 @@ public:
 
     ExecutionResult run_script_capability(const std::string& plugin_key, const std::string& capability_name, std::string& error);
 
+    void dispatch_lifecycle_event(LifecycleEvent evt, const LifecycleEventContext& ctx);
+
 private:
     PluginManager()                                = default;
     PluginManager(const PluginManager&)            = delete;
diff --git a/src/slic3r/plugin/PyPluginTrampoline.hpp b/src/slic3r/plugin/PyPluginTrampoline.hpp
index ad7fe25f10..4c77f1ba9c 100644
--- a/src/slic3r/plugin/PyPluginTrampoline.hpp
+++ b/src/slic3r/plugin/PyPluginTrampoline.hpp
@@ -132,6 +132,11 @@ public:
     {
         ORCA_PY_OVERRIDE_AUDITED([] {}, PYBIND11_OVERRIDE, void, Base, on_cancelled);
     }
+
+    void on_lifecycle_event(LifecycleEvent event, const LifecycleEventContext& ctx) override
+    {
+        ORCA_PY_OVERRIDE_AUDITED([] {}, PYBIND11_OVERRIDE, void, Base, on_lifecycle_event, event, ctx);
+    }
 };
 
 class PyPluginInterfaceTrampoline : public PyPluginCommonTrampoline<PluginCapabilityInterface>
diff --git a/src/slic3r/plugin/PythonPluginBridge.cpp b/src/slic3r/plugin/PythonPluginBridge.cpp
index 11bb6159cc..a88695005c 100644
--- a/src/slic3r/plugin/PythonPluginBridge.cpp
+++ b/src/slic3r/plugin/PythonPluginBridge.cpp
@@ -377,6 +377,61 @@ void bind_python_api(pybind11::module_& m)
         .value("FatalError", PluginResult::FatalError)
         .export_values();
 
+    py::enum_<LifecycleEvent>(m, "LifecycleEvent", "Application lifecycle moment passed to on_lifecycle_event")
+        .value("NewProject", LifecycleEvent::NewProject)
+        .value("ProjectOpened", LifecycleEvent::ProjectOpened)
+        .value("ProjectBeforeSave", LifecycleEvent::ProjectBeforeSave)
+        .value("ProjectAfterSave", LifecycleEvent::ProjectAfterSave)
+        .value("ProjectClosed", LifecycleEvent::ProjectClosed)
+        .value("ProjectDirtyChanged", LifecycleEvent::ProjectDirtyChanged)
+        .value("SliceStarted", LifecycleEvent::SliceStarted)
+        .value("SliceGeometryFinished", LifecycleEvent::SliceGeometryFinished)
+        .value("GCodeExportStarted", LifecycleEvent::GCodeExportStarted)
+        .value("GCodeExportFinished", LifecycleEvent::GCodeExportFinished)
+        .value("SlicingJobComplete", LifecycleEvent::SlicingJobComplete)
+        .value("ObjectAdded", LifecycleEvent::ObjectAdded)
+        .value("ObjectDeleted", LifecycleEvent::ObjectDeleted)
+        .value("ObjectTransformed", LifecycleEvent::ObjectTransformed)
+        .value("ObjectChanged", LifecycleEvent::ObjectChanged)
+        .value("ObjectRenamed", LifecycleEvent::ObjectRenamed)
+        .value("PlateCreated", LifecycleEvent::PlateCreated)
+        .value("PlateDeleted", LifecycleEvent::PlateDeleted)
+        .value("PlateSelected", LifecycleEvent::PlateSelected)
+        .value("PlateRenamed", LifecycleEvent::PlateRenamed)
+        .value("PresetSelected", LifecycleEvent::PresetSelected)
+        .value("PresetSaved", LifecycleEvent::PresetSaved)
+        .value("PrintStateChanged", LifecycleEvent::PrintStateChanged)
+        .value("DeviceOnline", LifecycleEvent::DeviceOnline)
+        .value("DeviceOffline", LifecycleEvent::DeviceOffline)
+        .value("DeviceDiscovered", LifecycleEvent::DeviceDiscovered)
+        .value("DeviceSelected", LifecycleEvent::DeviceSelected)
+        .value("UploadStarted", LifecycleEvent::UploadStarted)
+        .value("UploadFinished", LifecycleEvent::UploadFinished)
+        .value("PrintJobStarted", LifecycleEvent::PrintJobStarted)
+        .value("PrintJobFinished", LifecycleEvent::PrintJobFinished)
+        .value("SendJobStarted", LifecycleEvent::SendJobStarted)
+        .value("SendJobFinished", LifecycleEvent::SendJobFinished)
+        .export_values();
+
+    py::enum_<LifecycleEvtCode>(m, "LifecycleEvtCode", "Outcome code accompanying a LifecycleEventContext")
+        .value("Ok", LifecycleEvtCode::Ok)
+        .value("Error", LifecycleEvtCode::Error)
+        .value("Warn", LifecycleEvtCode::Warn)
+        .export_values();
+
+    py::class_<LifecycleEventContext>(m, "LifecycleEventContext", "Payload accompanying a LifecycleEvent")
+        .def(py::init<>())
+        .def_readonly("name", &LifecycleEventContext::name)
+        .def_readonly("code", &LifecycleEventContext::code)
+        .def_readonly("msg", &LifecycleEventContext::msg)
+        .def_readonly("id", &LifecycleEventContext::id)
+        .def_readonly("previous_name", &LifecycleEventContext::previous_name)
+        .def_readonly("device_id", &LifecycleEventContext::device_id)
+        .def_readonly("job_id", &LifecycleEventContext::job_id)
+        .def_readonly("source", &LifecycleEventContext::source)
+        .def_readonly("index", &LifecycleEventContext::index)
+        .def_readonly("dirty", &LifecycleEventContext::dirty);
+
     py::class_<PluginContext>(m, "PluginContext", "Context shared with plugin entry points")
         .def(py::init<>())
         .def_readwrite("orca_version", &PluginContext::orca_version);
@@ -401,6 +456,9 @@ void bind_python_api(pybind11::module_& m)
         .def("get_type", &PluginCapabilityInterface::get_type)
         .def("on_load", &PluginCapabilityInterface::on_load)
         .def("on_unload", &PluginCapabilityInterface::on_unload)
+        .def("on_lifecycle_event", &PluginCapabilityInterface::on_lifecycle_event,
+             "Override to react to an application lifecycle moment (LifecycleEvent) and its\n"
+             "LifecycleEventContext payload. Available on every capability type.")
         .def("has_config_ui", &PluginCapabilityInterface::has_config_ui,
              "Override to return True to replace the host's default JSON editor with your own HTML\n"
              "UI, returned by get_config_ui(). Every capability is configurable and appears in the\n"
diff --git a/src/slic3r/plugin/PythonPluginInterface.hpp b/src/slic3r/plugin/PythonPluginInterface.hpp
index 8b7518cf1c..2702275166 100644
--- a/src/slic3r/plugin/PythonPluginInterface.hpp
+++ b/src/slic3r/plugin/PythonPluginInterface.hpp
@@ -10,6 +10,8 @@
 #include <nlohmann/json.hpp>
 #include <pybind11/embed.h>
 
+#include <libslic3r/LifecycleEvents.hpp>
+
 namespace Slic3r {
 
 enum class PluginCapabilityType { PrinterConnection = 0, Pages, Analysis, Importer, Exporter, Visualization, Script, SlicingPipeline, Unknown };
@@ -167,6 +169,8 @@ public:
     virtual void on_unload() {}
     virtual void on_cancelled() {}
 
+    virtual void on_lifecycle_event(LifecycleEvent event, const LifecycleEventContext& ctx) { (void) event; (void) ctx; }
+
     // ── C++-only host state, never exposed to Python. Set by the loader at materialization. ──
     //
     // The capability owns its own identity and enable flag: they are read once under the GIL, live
diff --git a/tests/slic3rutils/test_plugin_lifecycle.cpp b/tests/slic3rutils/test_plugin_lifecycle.cpp
index 63a4e6827b..bac3a19ea9 100644
--- a/tests/slic3rutils/test_plugin_lifecycle.cpp
+++ b/tests/slic3rutils/test_plugin_lifecycle.cpp
@@ -1,5 +1,6 @@
 #include <catch2/catch_all.hpp>
 
+#include <libslic3r/LifecycleEvents.hpp>
 #include <libslic3r/Utils.hpp>
 #include <slic3r/plugin/PluginDescriptor.hpp>
 #include <slic3r/plugin/PluginManager.hpp>
@@ -12,8 +13,11 @@
 
 #include <algorithm>
 #include <chrono>
+#include <condition_variable>
 #include <fstream>
+#include <mutex>
 #include <string>
+#include <thread>
 #include <vector>
 
 using namespace Slic3r;
@@ -114,6 +118,72 @@ PluginDescriptor descriptor_of(PluginManager& manager, const std::string& plugin
 
 } // namespace
 
+TEST_CASE("Lifecycle hook shutdown drains concurrent dispatch", "[PluginLifecycle][LifecycleEvents]")
+{
+    std::mutex              mutex;
+    std::condition_variable cv;
+    bool                    callback_entered = false;
+    bool                    release_callback = false;
+    bool                    shutdown_started = false;
+    bool                    shutdown_finished = false;
+
+    set_lifecycle_hook_fn([&](LifecycleEvent, const LifecycleEventContext&) {
+        std::unique_lock<std::mutex> lock(mutex);
+        callback_entered = true;
+        cv.notify_all();
+        cv.wait(lock, [&] { return release_callback; });
+    });
+
+    std::thread dispatch_thread([] {
+        LifecycleEventContext ctx;
+        fire_lifecycle_event(LifecycleEvent::ProjectOpened, ctx);
+    });
+
+    bool callback_was_entered = false;
+    {
+        std::unique_lock<std::mutex> lock(mutex);
+        callback_was_entered = cv.wait_for(lock, std::chrono::seconds(5), [&] { return callback_entered; });
+    }
+    if (!callback_was_entered) {
+        {
+            std::lock_guard<std::mutex> lock(mutex);
+            release_callback = true;
+            cv.notify_all();
+        }
+        dispatch_thread.join();
+        set_lifecycle_hook_fn(nullptr);
+        FAIL("Lifecycle callback did not start");
+    }
+
+    std::thread shutdown_thread([&] {
+        {
+            std::lock_guard<std::mutex> lock(mutex);
+            shutdown_started = true;
+            cv.notify_all();
+        }
+        set_lifecycle_hook_fn(nullptr);
+        std::lock_guard<std::mutex> lock(mutex);
+        shutdown_finished = true;
+        cv.notify_all();
+    });
+
+    bool shutdown_was_started = false;
+    {
+        std::unique_lock<std::mutex> lock(mutex);
+        shutdown_was_started = cv.wait_for(lock, std::chrono::seconds(5), [&] { return shutdown_started; });
+        if (shutdown_was_started)
+            CHECK_FALSE(cv.wait_for(lock, std::chrono::milliseconds(100), [&] { return shutdown_finished; }));
+        release_callback = true;
+        cv.notify_all();
+    }
+
+    dispatch_thread.join();
+    shutdown_thread.join();
+    if (!shutdown_was_started)
+        FAIL("Lifecycle hook shutdown did not start");
+    CHECK(shutdown_finished);
+}
+
 TEST_CASE("A discovered script plugin loads and materializes its capability", "[PluginLifecycle][Python]")
 {
     ScopedPluginManager plugin_system;