@@ -10,5 +10,6 @@
 
 [CLI guide](./silabs_cli_guide.md)
 [Common app behavior](./silabs_common_app_behavior.md)
+[Extending base app implementation](./silabs_extending_base_app_implementation.md)
 [EFR32 software update](./silabs_efr32_software_update.md)
 [Getting Started](./silabs_getting_started.md)
@@ -0,0 +1,172 @@
+# Extending Base App Implementation
+
+## Introduction
+
+Silicon Labs Matter sample apps that support project upgrades use the Curiously
+Recurring Template Pattern (CRTP) so you can customize application behavior
+without editing the default `AppTask` implementation. Override `*Impl()` hooks
+in `CustomerAppTask` instead of modifying `AppTask.cpp` directly.
+
+-   [Introduction](#introduction)
+-   [CustomerAppTask](#customerapptask)
+-   [How to Override APIs](#how-to-override-apis)
+-   [DataModelCallbacks and CustomerAppTask](#datamodelcallbacks-and-customerapptask)
+-   [Sample Implementation](#sample-implementation)
+-   [Override API Reference](#override-api-reference)
+
+## CustomerAppTask
+
+To implement custom app behavior you can override any Silicon Labs implemented
+API in the CustomerAppTask file. Each sample app provides
+[`CustomerAppTask.h`](../../../examples/platform/silabs/customer/CustomerAppTask.h)
+and
+[`CustomerAppTask.cpp`](../../../examples/platform/silabs/customer/CustomerAppTask.cpp)
+for that purpose. The base implementation and the full set of overridable
+`*Impl()` APIs live in that example's source tree under `include/AppTaskImpl.h`
+and `src/AppTask.cpp`. Any `*Impl()` you do not override keeps the Silicon Labs
+default behavior.
+
+To customize behavior, copy
+[`CustomerAppTask.h`](../../../examples/platform/silabs/customer/CustomerAppTask.h)
+and
+[`CustomerAppTask.cpp`](../../../examples/platform/silabs/customer/CustomerAppTask.cpp)
+from `examples/platform/silabs/customer/` into your app's `include/` and `src/`
+folders, then update the corresponding paths in `BUILD.gn`.
+
+## How to Override APIs
+
+`CustomerAppTask` derives from the base AppTask through the Curiously Recurring
+Template Pattern (CRTP). You override only the `*Impl()` methods you need; the
+base declares one `*Impl()` per overridable API. Steps:
+
+1. Find the method to override in the base API (see
+   [Override API reference](#override-api-reference) below).
+2. Declare the same method signature in `CustomerAppTask` in your
+   `CustomerAppTask.h` under `private:`. Match the base `*Impl()` signature
+   exactly — note that `*Impl()` overrides are **non-static instance methods**
+   even when the public dispatcher (e.g. `ButtonEventHandler`) is `static`.
+3. Implement the method in `CustomerAppTask.cpp`.
+4. Build. The CRTP layer automatically routes each call to your `*Impl()` if
+   present, otherwise to the Silicon Labs default.
+
+## DataModelCallbacks and CustomerAppTask
+
+What used to live in `DataModelCallbacks.cpp` before Matter Extension 2.9.0 now
+lives in `AppTask.cpp`. The Matter SDK's `MatterPostAttributeChangeCallback` is
+implemented in
+[`examples/platform/silabs/BaseApplication.cpp`](../../../examples/platform/silabs/BaseApplication.cpp)
+and forwards to `AppTask::DMPostAttributeChangeCallback` (defined in
+`AppTask.cpp`), which you can customize via
+`DMPostAttributeChangeCallbackImpl()` in `CustomerAppTask`.
+
+Forwarding into `AppTask` still goes through CRTP as in
+[How to Override APIs](#how-to-override-apis).
+
+-   **Methods that already exist in the AppTask** — Customize them by overriding
+    the matching `*Impl()` method in `CustomerAppTask`. Do not edit
+    `AppTask.cpp` for app-specific behavior.
+
+-   **New custom data model methods** — Add them in `CustomerAppTask` directly.
+    Do not add new application logic in autogenerated sources; those edits will
+    not survive regeneration or project upgrades.
+
+## Sample Implementation
+
+The following shows a minimal example `CustomerAppTask` that overrides
+`AppInitImpl()` and `ButtonEventHandlerImpl()` from the lighting app
+implementation.
+
+**CustomerAppTask.h**
+
+```cpp
+#pragma once
+#include "AppTaskImpl.h"
+
+/**
+ * Minimal AppTaskImpl-derived class. Override only the *Impl() methods you need;
+ * add AppInitImpl(), GetAppTask(), and sAppTask as required by the CRTP base.
+ */
+class CustomerAppTask : public AppTaskImpl<CustomerAppTask>
+{
+public:
+    static CustomerAppTask & GetAppTask() { return sAppTask; }
+
+private:
+    friend class AppTaskImpl<CustomerAppTask>;
+    CHIP_ERROR AppInitImpl();
+    void ButtonEventHandlerImpl(uint8_t button, uint8_t btnAction);
+    static CustomerAppTask sAppTask;
+};
+```
+
+**CustomerAppTask.cpp**
+
+```cpp
+#include "CustomerAppTask.h"
+#include "AppTask.h"
+#include "AppConfig.h"
+#include "AppEvent.h"
+#include <platform/CHIPDeviceLayer.h>
+#include <platform/silabs/platformAbstraction/SilabsPlatform.h>
+
+using namespace ::chip::DeviceLayer::Silabs;
+
+#define APP_FUNCTION_BUTTON 0
+#define APP_LIGHT_SWITCH     1
+
+CustomerAppTask CustomerAppTask::sAppTask;
+
+AppTask & AppTask::GetAppTask()
+{
+    return CustomerAppTask::GetAppTask();
+}
+
+CHIP_ERROR CustomerAppTask::AppInitImpl()
+{
+    SILABS_LOG("CustomerAppTask: custom implementation (AppInitImpl)");
+    CHIP_ERROR err = this->AppTask::AppInit();
+    if (err == CHIP_NO_ERROR)
+    {
+        // Override the SDK default button handler registered in AppTask::AppInit().
+        chip::DeviceLayer::Silabs::GetPlatform().SetButtonsCb(CustomerAppTask::ButtonEventHandler);
+    }
+    return err;
+}
+
+void CustomerAppTask::ButtonEventHandlerImpl(uint8_t button, uint8_t btnAction)
+{
+    SILABS_LOG("CustomerAppTask: custom implementation (ButtonEventHandlerImpl)");
+    AppEvent button_event           = {};
+    button_event.Type               = AppEvent::kEventType_Button;
+    button_event.ButtonEvent.Action = btnAction;
+    if (button == APP_LIGHT_SWITCH && btnAction == static_cast<uint8_t>(SilabsPlatform::ButtonAction::ButtonPressed))
+    {
+        button_event.Handler = LightActionEventHandler;
+        AppTask::GetAppTask().PostEvent(&button_event);
+    }
+    else if (button == APP_FUNCTION_BUTTON)
+    {
+        button_event.Handler = BaseApplication::ButtonHandler;
+        AppTask::GetAppTask().PostEvent(&button_event);
+    }
+}
+```
+
+## Override API Reference
+
+`CHIP_ERROR StartAppTask()` is declared on `AppTask` only. It is not an
+`*Impl()` hook: platform code (for example `MatterConfig`) calls
+`AppTask::GetAppTask().StartAppTask()` with static type `AppTask &`, which runs
+the implementation in `AppTask.cpp` (creating the FreeRTOS app task via
+`BaseApplication::StartAppTask(...)`). To change startup behavior, edit
+`AppTask::StartAppTask()` or `BaseApplication::StartAppTask` in your product
+sources.
+
+The base API and default AppTask behavior for each sample app are maintained
+under that app's `include/AppTaskImpl.h` and `src/AppTask.cpp`. Use those files
+as the reference for overridable methods and app configuration.
+
+| File                    | Purpose                                                                                                                                              |
+| ----------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------- |
+| `include/AppTaskImpl.h` | Declarations of every overridable `*Impl()` method. Copy the signatures you need from here into `CustomerAppTask.h`.                                 |
+| `src/AppTask.cpp`       | Silicon Labs default implementation of AppTask. This is what runs for any `*Impl()` you do not override. Use as reference when customizing behavior. |
@@ -7,11 +7,6 @@ An example showing the use of CHIP on the Silicon Labs EFR32 MG24.
 -   [Matter Air Quality Sensor Example](#matter-air-quality-sensor-example)
     -   [Introduction](#introduction)
     -   [Extending Base App Implementation](#extending-base-app-implementation)
-        -   [CustomerAppTask](#customerapptask)
-        -   [How to Override APIs](#how-to-override-apis)
-        -   [DataModelCallbacks and CustomerAppTask](#datamodelcallbacks-and-customerapptask)
-        -   [Sample Implementation](#sample-implementation)
-        -   [Override API Reference](#override-api-reference)
     -   [Building](#building)
         -   [Linux](#linux)
         -   [Mac OS X](#mac-os-x)
@@ -63,145 +58,14 @@ the Silicon Labs platform.
 
 ## Extending Base App Implementation
 
-### CustomerAppTask
-
-To implement custom app behavior you can override any Silicon Labs implemented
-API in the CustomerAppTask file. This example provides
-[`CustomerAppTask.h`](../../platform/silabs/customer/CustomerAppTask.h) and
-[`CustomerAppTask.cpp`](../../platform/silabs/customer/CustomerAppTask.cpp) for
-that purpose. The base implementation and the full set of overridable `*Impl()`
-APIs live in this example's source tree under
-[`include/AppTaskImpl.h`](include/AppTaskImpl.h) and
-[`src/AppTask.cpp`](src/AppTask.cpp). Any `*Impl()` you do not override keeps
-the Silicon Labs default behavior. To customize behavior, copy
-[`CustomerAppTask.h`](../../platform/silabs/customer/CustomerAppTask.h) and
-[`CustomerAppTask.cpp`](../../platform/silabs/customer/CustomerAppTask.cpp) from
-`examples/platform/silabs/customer/` into this app's `include/` and `src/`
-folders, then update the corresponding paths in `BUILD.gn`.
-
-### How to Override APIs
-
-`CustomerAppTask` derives from the base AppTask through the Curiously Recurring
-Template Pattern (CRTP). You override only the `*Impl()` methods you need, the
-base declares one `*Impl()` per overridable API. Steps:
-
-1. Find the method to override in the base API (see
-   [Override API reference](#override-api-reference) below).
-2. Declare the same method signature in `CustomerAppTask` in your
-   `CustomerAppTask.h` under `private:`. Match the base `*Impl()` signature
-   exactly — note that `*Impl()` overrides are **non-static instance methods**
-   even when the public dispatcher (e.g. `ButtonEventHandler`) is `static`.
-3. Implement the method in `CustomerAppTask.cpp`.
-4. Build. The CRTP layer automatically routes each call to your `*Impl()` if
-   present, otherwise to the Silicon Labs default.
-
-### DataModelCallbacks and CustomerAppTask
-
-What used to live in `DataModelCallbacks.cpp` now lives in `AppTask.cpp`. The
-Matter SDK's `MatterPostAttributeChangeCallback` is implemented in
-`examples/platform/silabs/BaseApplication.cpp` and forwards to
-`AppTask::DMPostAttributeChangeCallback` (defined in `AppTask.cpp`), which you
-can customize via `DMPostAttributeChangeCallbackImpl()` in `CustomerAppTask`.
-
-Forwarding into `AppTask` still goes through CRTP as in
-[How to Override APIs](#how-to-override-apis).
-
--   **Methods that already exist in the AppTask** — Customize them by overriding
-    the matching `*Impl()` method in `CustomerAppTask`. Do not edit the
-    `AppTask.cpp` for app-specific behavior.
-
--   **New custom data model methods** — Add them in `CustomerAppTask` directly.
-    Do not add new application logic in autogenerated sources; those edits will
-    not survive regeneration or project upgrades.
-
-### Sample Implementation
-
-The following shows a minimal example `CustomerAppTask` that overrides
-`AppInitImpl()` and `ButtonEventHandlerImpl()`.
-
-**CustomerAppTask.h**
-
-```cpp
-#pragma once
-#include "AppTaskImpl.h"
-
-/** Minimal AppTaskImpl-derived class. Override only the *Impl() methods you need **/
-class CustomerAppTask : public AppTaskImpl<CustomerAppTask>
-{
-public:
-    static CustomerAppTask & GetAppTask() { return sAppTask; }
-
-private:
-    friend class AppTaskImpl<CustomerAppTask>;
-    CHIP_ERROR AppInitImpl();
-    void ButtonEventHandlerImpl(uint8_t button, uint8_t btnAction);
-    static CustomerAppTask sAppTask;
-};
-```
-
-**CustomerAppTask.cpp**
-
-```cpp
-#include "CustomerAppTask.h"
-#include "AppTask.h"
-#include "AppEvent.h"
-#include <platform/CHIPDeviceLayer.h>
-#include <platform/silabs/platformAbstraction/SilabsPlatform.h>
-
-#define APP_FUNCTION_BUTTON 0
-
-CustomerAppTask CustomerAppTask::sAppTask;
-
-AppTask & AppTask::GetAppTask()
-{
-    return CustomerAppTask::GetAppTask();
-}
-
-CHIP_ERROR CustomerAppTask::AppInitImpl()
-{
-    SILABS_LOG("CustomerAppTask: custom implementation (AppInitImpl)");
-    CHIP_ERROR err = AppTask::AppInit();
-    if (err == CHIP_NO_ERROR)
-    {
-        // Override the SDK default button handler registered in AppTask::AppInit().
-        chip::DeviceLayer::Silabs::GetPlatform().SetButtonsCb(CustomerAppTask::ButtonEventHandler);
-    }
-    return err;
-}
-
-void CustomerAppTask::ButtonEventHandlerImpl(uint8_t button, uint8_t btnAction)
-{
-    SILABS_LOG("CustomerAppTask: custom implementation (ButtonEventHandlerImpl)");
-    AppEvent aEvent           = {};
-    aEvent.Type               = AppEvent::kEventType_Button;
-    aEvent.ButtonEvent.Action = btnAction;
-
-    if (button == APP_FUNCTION_BUTTON)
-    {
-        aEvent.Handler = BaseApplication::ButtonHandler;
-        AppTask::GetAppTask().PostEvent(&aEvent);
-    }
-}
-```
-
-### Override API Reference
-
-`CHIP_ERROR StartAppTask()` is declared on `AppTask` only. It is not an
-`*Impl()` hook: platform code (for example `MatterConfig`) calls
-`AppTask::GetAppTask().StartAppTask()` with static type `AppTask &`, which runs
-the implementation in `AppTask.cpp` (creating the FreeRTOS app task via
-`BaseApplication::StartAppTask(...)`). To change startup behavior, edit
-`AppTask::StartAppTask()` or `BaseApplication::StartAppTask` in your product
-sources.
-
-The base API and default AppTask behavior for this example are maintained under
-[`include/`](include/AppTaskImpl.h) and [`src/`](src/AppTask.cpp). Use them as
-the reference for overridable methods and app configuration.
-
-| File                                             | Purpose                                                                                                                                              |
-| ------------------------------------------------ | ---------------------------------------------------------------------------------------------------------------------------------------------------- |
-| [`include/AppTaskImpl.h`](include/AppTaskImpl.h) | Declarations of every overridable `*Impl()` method. Copy the signatures you need from here into `CustomerAppTask.h`.                                 |
-| [`src/AppTask.cpp`](src/AppTask.cpp)             | Silicon Labs default implementation of AppTask. This is what runs for any `*Impl()` you do not override. Use as reference when customizing behavior. |
+See
+[Extending Base App Implementation](../../../docs/platforms/silabs/silabs_extending_base_app_implementation.md)
+for how to customize application behavior using `CustomerAppTask` and CRTP
+`*Impl()` hooks.
+
+Per-example override API references:
+[`include/AppTaskImpl.h`](include/AppTaskImpl.h),
+[`src/AppTask.cpp`](src/AppTask.cpp).
 
 ## Building
 
 
@@ -81,6 +81,7 @@ The application supports the following device types (specified via the
 -   `dimmable-light`
 -   `dimmable-plug-in-unit`
 -   `dishwasher`
+-   `doorbell`
 -   `electrical-sensor`
 -   `extractor-hood`
 -   `fan`
@@ -131,7 +132,7 @@ Usage: ./out/linux-x64-all-devices-boringssl-no-ble/all-devices-app
 
 PROGRAM OPTIONS
 
-  --device <aggregator|air-purifier|air-quality-sensor|air-quality-sensor-full|ambient-context-sensor|bridged-node|chime|commissioning-proxy|contact-sensor|cooktop|device-energy-management|dimmable-light|dimmable-plug-in-unit|dishwasher|electrical-sensor|extractor-hood|fan|fan-no-onoff|flow-sensor|generic-switch|humidity-conditioner|humidity-sensor|laundry-dryer|laundry-washer|light-sensor|microwave-oven|mode-select|mounted-dimmable-load-control|mounted-on-off-control|network-infrastructure-manager|occupancy-sensor|on-off-light|on-off-light-switch|on-off-plug-in-unit|oven|oven-2|power-source|pressure-sensor|proximity-ranger|rain-sensor|refrigerator|refrigerator-2|robotic-vacuum-cleaner|room-air-conditioner|room-air-conditioner-with-sensors|smoke-co-alarm|soil-sensor|speaker|temperature-sensor|thread-border-router|water-freeze-detector|water-leak-detector|water-valve|window-covering>
+  --device <aggregator|air-purifier|air-quality-sensor|air-quality-sensor-full|ambient-context-sensor|bridged-node|chime|commissioning-proxy|contact-sensor|cooktop|device-energy-management|dimmable-light|dimmable-plug-in-unit|dishwasher|doorbell|electrical-sensor|extractor-hood|fan|fan-no-onoff|flow-sensor|generic-switch|humidity-conditioner|humidity-sensor|laundry-dryer|laundry-washer|light-sensor|microwave-oven|mode-select|mounted-dimmable-load-control|mounted-on-off-control|network-infrastructure-manager|occupancy-sensor|on-off-light|on-off-light-switch|on-off-plug-in-unit|oven|oven-2|power-source|pressure-sensor|proximity-ranger|rain-sensor|refrigerator|refrigerator-2|robotic-vacuum-cleaner|room-air-conditioner|room-air-conditioner-with-sensors|smoke-co-alarm|soil-sensor|speaker|temperature-sensor|thread-border-router|water-freeze-detector|water-leak-detector|water-valve|window-covering>
        Select the device to start up. Format: 'type' or 'type:endpoint' or 'type:endpoint,parent=parentId'
        Can be specified multiple times for multi-endpoint devices.
        Example: --device chime:1 --device speaker:2,parent=1
 
@@ -48,6 +48,7 @@ source_set("device-factory") {
     "${chip_root}/examples/all-devices-app/all-devices-common/device/types/dimmable-light:logging",
     "${chip_root}/examples/all-devices-app/all-devices-common/device/types/dimmable-plug-in-unit",
     "${chip_root}/examples/all-devices-app/all-devices-common/device/types/dishwasher:emulated",
+    "${chip_root}/examples/all-devices-app/all-devices-common/device/types/doorbell",
     "${chip_root}/examples/all-devices-app/all-devices-common/device/types/electrical-sensor:logging",
     "${chip_root}/examples/all-devices-app/all-devices-common/device/types/extended-color-light:logging",
     "${chip_root}/examples/all-devices-app/all-devices-common/device/types/extractor-hood",
 
@@ -38,6 +38,7 @@
 #include <device/types/dimmable-light/impl/LoggingDimmableLight.h>
 #include <device/types/dimmable-plug-in-unit/DimmablePlugInUnit.h>
 #include <device/types/dishwasher/impl/EmulatedDishwasher.h>
+#include <device/types/doorbell/Doorbell.h>
 #include <device/types/electrical-sensor/impl/SimulatedElectricalSensor.h>
 #include <device/types/extended-color-light/impl/LoggingExtendedColorLight.h>
 #include <device/types/extractor-hood/ExtractorHood.h>
@@ -530,6 +531,19 @@ class DeviceFactory
                     MountedDimmableLoadControl::Config{ .levelControl = DimmableLoad::LevelControlConfig::CiPicsDefaults() });
             });
         }
+        if constexpr (ALL_DEVICES_ENABLE_DOORBELL)
+        {
+            RegisterCreator("doorbell", [this]() {
+                VerifyOrDie(mContext.has_value());
+                return MakeDevice<Doorbell>(Doorbell::Config{
+                    .timerDelegate    = mContext->timerDelegate,
+                    .platformManager  = mContext->platformManager,
+                    .bindingTable     = mContext->bindingTable,
+                    .bindingManager   = mContext->bindingManager,
+                    .identifyDelegate = mContext->identifyDelegate,
+                });
+            });
+        }
         if constexpr (ALL_DEVICES_ENABLE_MOUNTED_ON_OFF_CONTROL)
         {
             RegisterCreator("mounted-on-off-control", [this]() {