diff --git a/dcs/main.py b/dcs/main.py
index e69de29..46a9676 100644
--- a/dcs/main.py
+++ b/dcs/main.py
@@ -0,0 +1,3 @@
+# -*- coding: UTF-8 -*-
+import server
+import requestHandler
diff --git a/dcs/requestHandler.py b/dcs/requestHandler.py
new file mode 100644
index 0000000..a26c914
--- /dev/null
+++ b/dcs/requestHandler.py
@@ -0,0 +1,31 @@
+import socket
+import threading
+import json
+import struct
+
+
+class RequestHandler(threading.Thread):
+    def __init__(self, file_server: 'FileServer', client_socket: 'socket.socket', request_map: 'dict'):
+        super().__init__()
+        self.file_server = file_server
+        self.client_socket = client_socket
+        self.request_map = request_map
+        self.daemon = True
+        pass
+
+    def run(self) -> None:
+        try:
+            if self.request_map['action'] == 'getFileSize':
+                print(f"[REQUEST] getFileSize")
+                response = {
+                    'fileSize': self.file_server.get_file_size()
+                }
+                response_binary = json.JSONEncoder().encode(response).encode("utf-8")
+                response_binary_len = len(response_binary)
+                response_binary_len_binary = struct.pack("!Q", response_binary_len)
+
+                response_binary = response_binary_len_binary + response_binary
+                self.client_socket.sendall(response_binary)
+                print(f"[RESPONSE] file size: {response['fileSize']}, header size: {response_binary_len}")
+        finally:
+            self.client_socket.close()
diff --git a/dcs/server.py b/dcs/server.py
new file mode 100644
index 0000000..8b13789
--- /dev/null
+++ b/dcs/server.py
@@ -0,0 +1 @@
+