diff --git a/docs/imgs/qt_app_embed.gif b/docs/imgs/qt_app_embed.gif
new file mode 100644
index 0000000..012d9ec
Binary files /dev/null and b/docs/imgs/qt_app_embed.gif differ
diff --git a/docs/qt_embed.md b/docs/qt_embed.md
new file mode 100644
index 0000000..e78a8fe
--- /dev/null
+++ b/docs/qt_embed.md
@@ -0,0 +1,46 @@
+# Embeding generated window to a PyQt app
+
+You can integrate oneFace generated Qt windows by embedding them in a Qt application:
+
+```Python
+# demo_qt_embed.py
+import sys
+from oneface.qt import gui
+from oneface import one
+from qtpy import QtWidgets
+
+app = QtWidgets.QApplication([])
+
+
+@gui
+@one
+def add(a: int, b: int):
+    res = a + b
+    print(res)
+
+@gui
+@one
+def mul(a: int, b: int):
+    res = a * b
+    print(res)
+
+
+main_window = QtWidgets.QWidget()
+main_window.setWindowTitle("MyApp")
+main_window.setFixedSize(200, 100)
+layout = QtWidgets.QVBoxLayout(main_window)
+layout.addWidget(QtWidgets.QLabel("Apps:"))
+btn_open_add = QtWidgets.QPushButton("add")
+btn_open_mul = QtWidgets.QPushButton("mul")
+btn_open_add.clicked.connect(add.window.show)
+btn_open_mul.clicked.connect(mul.window.show)
+layout.addWidget(btn_open_add)
+layout.addWidget(btn_open_mul)
+main_window.show()
+
+sys.exit(app.exec())
+```
+
+Run it:
+
+![qt_embed](imgs/qt_app_embed.gif)
diff --git a/mkdocs.yml b/mkdocs.yml
index 75f1d6d..f699e06 100644
--- a/mkdocs.yml
+++ b/mkdocs.yml
@@ -14,6 +14,7 @@ nav:
     - Dash configs: dash_confs.md
   - Wrap command line: wrap_cli.md
   - Embedding:
+    - qt_embed.md
     - dash_embed.md
 
 markdown_extensions:
diff --git a/oneface/__init__.py b/oneface/__init__.py
index 8e07126..83b05c0 100644
--- a/oneface/__init__.py
+++ b/oneface/__init__.py
@@ -1,5 +1,5 @@
 from .core import one, Arg
 
-__version__ = '0.1.7'
+__version__ = '0.1.8'
 
 __all__ = [one, Arg]
diff --git a/oneface/qt.py b/oneface/qt.py
index a99746a..3ba0c3e 100644
--- a/oneface/qt.py
+++ b/oneface/qt.py
@@ -1,3 +1,4 @@
+import typing as T
 import functools
 from qtpy import QtWidgets
 from qtpy import QtCore
@@ -26,28 +27,38 @@ def gui(func=None, **kwargs):
     return GUI(func, **kwargs)
 
 
+def get_app():
+    app = QtWidgets.QApplication.instance()
+    if app is None:
+        app = QtWidgets.QApplication([])
+    return app
+
+
 class GUI():
 
     type_to_widget_constructor = {}
 
-    def __init__(self, func, name=None, size=None,
-                 run_once=True):
+    def __init__(
+            self,
+            func: T.Callable, name: T.Optional[str] = None,
+            size: T.Optional[T.List] = None,
+            run_once=True):
         self.func = func
         self.run_once = run_once
         self.result = None
-        self.app = QtWidgets.QApplication([])
-        self.main_window = QtWidgets.QMainWindow()
+        self.app = get_app()
         if name is not None:
-            name = name
+            self.name = name
         elif hasattr(func, "name"):
-            name = func.name
+            self.name = func.name
         else:
-            name = func.__name__
-        self.main_window.setWindowTitle(name)
+            self.name = func.__name__
+        self.window = QtWidgets.QWidget()
+        self.window._oneface_wrap = self
+        self.window.setWindowTitle(self.name)
         if size:
-            self.main_window.setFixedSize(*size)
+            self.window.setFixedSize(*size)
         self.arg_widgets = {}
-        self.window = QtWidgets.QWidget()
         self.layout = QtWidgets.QVBoxLayout()
         self.compose_ui()
         self.connect_events()
@@ -58,7 +69,6 @@ def compose_ui(self):
         self.layout.addWidget(self.run_btn)
         self.terminal = QtWidgets.QTextEdit()
         self.window.setLayout(self.layout)
-        self.main_window.setCentralWidget(self.window)
 
     def compose_arg_widgets(self, layout: QtWidgets.QVBoxLayout):
         arg_objs = get_func_argobjs(self.func)
@@ -86,9 +96,9 @@ def get_args(self):
     def run_func(self):
         kwargs = self.get_args()
         if self.run_once:
-            self.main_window.hide()
+            self.window.hide()
             self.result = self.func(**kwargs)
-            self.main_window.close()
+            self.window.close()
         else:
             thread = self.thread = QtCore.QThread()
             worker = self.worker = Worker(self.func, kwargs)
@@ -106,7 +116,7 @@ def finish():
             thread.finished.connect(finish)
 
     def __call__(self):
-        self.main_window.show()
+        self.window.show()
         self.app.exec()
         return self.result