diff --git a/src/core/CMakeLists.txt b/src/core/CMakeLists.txt
index 91a0adce..a3eb378f 100644
--- a/src/core/CMakeLists.txt
+++ b/src/core/CMakeLists.txt
@@ -22,6 +22,7 @@ ecm_qt_declare_logging_category(
   "Bismuth Plasma Tiling Extension")
 
 add_subdirectory(plasma-api)
+add_subdirectory(engine)
 
 target_sources(bismuth_core PRIVATE qml-plugin.cpp ts-proxy.cpp controller.cpp
                                     qmldir ${BISMUTH_LOG})
diff --git a/src/core/controller.cpp b/src/core/controller.cpp
index 8ab9fb34..97109936 100644
--- a/src/core/controller.cpp
+++ b/src/core/controller.cpp
@@ -13,6 +13,7 @@
 
 #include <memory>
 
+#include "engine/engine.hpp"
 #include "logger.hpp"
 #include "plasma-api/client.hpp"
 #include "plasma-api/workspace.hpp"
@@ -20,9 +21,10 @@
 
 namespace Bismuth
 {
-Controller::Controller(PlasmaApi::Api &api)
+Controller::Controller(PlasmaApi::Api &api, Engine &engine)
     : m_plasmaApi(api)
     , m_proxy()
+    , m_engine(engine)
 {
     bindEvents();
 }
@@ -34,6 +36,7 @@ void Controller::bindEvents()
     connect(&workspace, &PlasmaApi::Workspace::numberScreensChanged, this, &Controller::onSurfaceUpdate);
     connect(&workspace, &PlasmaApi::Workspace::screenResized, this, &Controller::onSurfaceUpdate);
     connect(&workspace, &PlasmaApi::Workspace::currentActivityChanged, this, &Controller::onCurrentSurfaceChanged);
+    connect(&workspace, &PlasmaApi::Workspace::clientAdded, this, &Controller::onClientAdded);
 }
 
 void Controller::registerAction(const Action &data)
@@ -77,6 +80,11 @@ void Controller::onSurfaceUpdate()
     }
 }
 
+void Controller::onClientAdded(PlasmaApi::Client client)
+{
+    m_engine.addWindow(client);
+}
+
 void Controller::setProxy(TSProxy *proxy)
 {
     m_proxy = proxy;
diff --git a/src/core/controller.hpp b/src/core/controller.hpp
index 62d9681d..206164fe 100644
--- a/src/core/controller.hpp
+++ b/src/core/controller.hpp
@@ -11,7 +11,9 @@
 #include <memory>
 #include <vector>
 
+#include "engine/engine.hpp"
 #include "plasma-api/api.hpp"
+#include "plasma-api/client.hpp"
 
 class TSProxy;
 
@@ -31,7 +33,7 @@ class Controller : public QObject
 {
     Q_OBJECT
 public:
-    Controller(PlasmaApi::Api &);
+    Controller(PlasmaApi::Api &, Engine &);
 
     void bindEvents();
     void registerAction(const Action &);
@@ -41,12 +43,14 @@ public:
 public Q_SLOTS:
     void onCurrentSurfaceChanged();
     void onSurfaceUpdate();
+    void onClientAdded(PlasmaApi::Client);
 
 private:
     std::vector<QAction *> m_registeredShortcuts{};
 
     PlasmaApi::Api &m_plasmaApi;
     TSProxy *m_proxy;
+    Engine &m_engine;
 };
 
 }
diff --git a/src/core/engine/CMakeLists.txt b/src/core/engine/CMakeLists.txt
new file mode 100644
index 00000000..b694cd81
--- /dev/null
+++ b/src/core/engine/CMakeLists.txt
@@ -0,0 +1,4 @@
+# SPDX-FileCopyrightText: 2022 Mikhail Zolotukhin <mail@gikari.com>
+# SPDX-License-Identifier: MIT
+
+target_sources(bismuth_core PRIVATE engine.cpp windows_list.cpp window.cpp)
diff --git a/src/core/engine/engine.cpp b/src/core/engine/engine.cpp
new file mode 100644
index 00000000..be182e4a
--- /dev/null
+++ b/src/core/engine/engine.cpp
@@ -0,0 +1,17 @@
+// SPDX-FileCopyrightText: 2022 Mikhail Zolotukhin <mail@gikari.com>
+// SPDX-License-Identifier: MIT
+
+#include "engine.hpp"
+
+namespace Bismuth
+{
+Engine::Engine()
+{
+}
+
+void Engine::addWindow(PlasmaApi::Client client)
+{
+    m_windows.add(client);
+    // Bind events of this window
+}
+}
diff --git a/src/core/engine/engine.hpp b/src/core/engine/engine.hpp
new file mode 100644
index 00000000..e55df491
--- /dev/null
+++ b/src/core/engine/engine.hpp
@@ -0,0 +1,21 @@
+// SPDX-FileCopyrightText: 2022 Mikhail Zolotukhin <mail@gikari.com>
+// SPDX-License-Identifier: MIT
+
+#pragma once
+
+#include "plasma-api/client.hpp"
+#include "windows_list.hpp"
+
+namespace Bismuth
+{
+class Engine
+{
+public:
+    Engine();
+
+    void addWindow(PlasmaApi::Client);
+
+private:
+    WindowsList m_windows{};
+};
+}
diff --git a/src/core/engine/window.cpp b/src/core/engine/window.cpp
new file mode 100644
index 00000000..57588209
--- /dev/null
+++ b/src/core/engine/window.cpp
@@ -0,0 +1,9 @@
+// SPDX-FileCopyrightText: 2022 Mikhail Zolotukhin <mail@gikari.com>
+// SPDX-License-Identifier: MIT
+
+#include "window.hpp"
+
+namespace Bismuth
+{
+
+}
diff --git a/src/core/engine/window.hpp b/src/core/engine/window.hpp
new file mode 100644
index 00000000..63e44655
--- /dev/null
+++ b/src/core/engine/window.hpp
@@ -0,0 +1,11 @@
+// SPDX-FileCopyrightText: 2022 Mikhail Zolotukhin <mail@gikari.com>
+// SPDX-License-Identifier: MIT
+
+#pragma once
+
+namespace Bismuth
+{
+class Window
+{
+};
+}
diff --git a/src/core/engine/windows_list.cpp b/src/core/engine/windows_list.cpp
new file mode 100644
index 00000000..1d54112b
--- /dev/null
+++ b/src/core/engine/windows_list.cpp
@@ -0,0 +1,14 @@
+// SPDX-FileCopyrightText: 2022 Mikhail Zolotukhin <mail@gikari.com>
+// SPDX-License-Identifier: MIT
+
+#include "windows_list.hpp"
+#include "logger.hpp"
+
+namespace Bismuth
+{
+
+void WindowsList::add(PlasmaApi::Client)
+{
+    qDebug(Bi) << "Adding window... (CXX)";
+}
+}
diff --git a/src/core/engine/windows_list.hpp b/src/core/engine/windows_list.hpp
new file mode 100644
index 00000000..ff6be7de
--- /dev/null
+++ b/src/core/engine/windows_list.hpp
@@ -0,0 +1,19 @@
+// SPDX-FileCopyrightText: 2022 Mikhail Zolotukhin <mail@gikari.com>
+// SPDX-License-Identifier: MIT
+
+#pragma once
+
+#include "plasma-api/client.hpp"
+#include "window.hpp"
+
+namespace Bismuth
+{
+class WindowsList
+{
+public:
+    void add(PlasmaApi::Client);
+
+private:
+    std::map<PlasmaApi::Client, Window> m_windowMap{};
+};
+}
diff --git a/src/core/qml-plugin.cpp b/src/core/qml-plugin.cpp
index 7d56fb82..c528565f 100644
--- a/src/core/qml-plugin.cpp
+++ b/src/core/qml-plugin.cpp
@@ -13,6 +13,7 @@
 
 #include "config.hpp"
 #include "controller.hpp"
+#include "engine/engine.hpp"
 #include "logger.hpp"
 #include "plasma-api/api.hpp"
 #include "ts-proxy.hpp"
@@ -27,7 +28,7 @@ void CorePlugin::registerTypes(const char *uri)
 
 Core::Core(QQuickItem *parent)
     : QQuickItem(parent)
-    , m_engine() // We cannot get engine from the pointer in the constructor
+    , m_qmlEngine() // We cannot get engine from the pointer in the constructor
     , m_controller()
     , m_tsProxy()
     , m_config()
@@ -41,10 +42,11 @@ Core::Core(QQuickItem *parent)
 void Core::init()
 {
     m_config = std::make_unique<Bismuth::Config>();
-    m_engine = qmlEngine(this);
-    m_plasmaApi = std::make_unique<PlasmaApi::Api>(m_engine);
-    m_controller = std::make_unique<Bismuth::Controller>(*m_plasmaApi);
-    m_tsProxy = std::make_unique<TSProxy>(m_engine, *m_controller, *m_plasmaApi, *m_config);
+    m_qmlEngine = qmlEngine(this);
+    m_plasmaApi = std::make_unique<PlasmaApi::Api>(m_qmlEngine);
+    m_engine = std::make_unique<Bismuth::Engine>();
+    m_controller = std::make_unique<Bismuth::Controller>(*m_plasmaApi, *m_engine);
+    m_tsProxy = std::make_unique<TSProxy>(m_qmlEngine, *m_controller, *m_plasmaApi, *m_config);
     m_controller->setProxy(m_tsProxy.get());
 }
 
diff --git a/src/core/qml-plugin.hpp b/src/core/qml-plugin.hpp
index af26c2c5..30350ec1 100644
--- a/src/core/qml-plugin.hpp
+++ b/src/core/qml-plugin.hpp
@@ -13,6 +13,7 @@
 
 #include "config.hpp"
 #include "controller.hpp"
+#include "engine/engine.hpp"
 #include "plasma-api/api.hpp"
 #include "ts-proxy.hpp"
 
@@ -44,10 +45,11 @@ public:
     TSProxy *tsProxy() const;
 
 private:
-    QQmlEngine *m_engine; ///< Pointer to the engine, that is currently using the Core element
+    QQmlEngine *m_qmlEngine; ///< Pointer to the engine, that is currently using the Core element
 
     std::unique_ptr<Bismuth::Controller> m_controller; ///< Legacy TS Backend proxy
     std::unique_ptr<TSProxy> m_tsProxy; ///< Legacy TS Backend proxy
     std::unique_ptr<Bismuth::Config> m_config;
     std::unique_ptr<PlasmaApi::Api> m_plasmaApi;
+    std::unique_ptr<Bismuth::Engine> m_engine;
 };