diff --git a/src/main.py b/src/main.py
new file mode 100644
index 0000000..95396a5
--- /dev/null
+++ b/src/main.py
@@ -0,0 +1,10 @@
+from src.model.frame import Frame
+from src.service.dialog_state_monitor import DialogStateMonitor
+
+
+# Example
+monitor = DialogStateMonitor()
+monitor.append(Frame('system', 'hello'))
+monitor.append(Frame('user', 'some text'))
+print(monitor.get_all()[0].text)
+print(monitor.get_last().text)
diff --git a/src/model/frame.py b/src/model/frame.py
new file mode 100644
index 0000000..bdbc717
--- /dev/null
+++ b/src/model/frame.py
@@ -0,0 +1,4 @@
+class Frame:
+    def __init__(self, source: str, text: str):
+        self.source = source
+        self.text = text
diff --git a/src/service/dialog_state_monitor.py b/src/service/dialog_state_monitor.py
new file mode 100644
index 0000000..9bfad0f
--- /dev/null
+++ b/src/service/dialog_state_monitor.py
@@ -0,0 +1,14 @@
+from src.model.frame import Frame
+
+
+class DialogStateMonitor:
+    dialog = []
+
+    def append(self, frame: Frame):
+        self.dialog.append(frame)
+
+    def get_all(self) -> [Frame]:
+        return self.dialog
+
+    def get_last(self) -> Frame:
+        return self.dialog[len(self.dialog) - 1]