diff --git a/android/app/src/debug/AndroidManifest.xml b/android/app/src/debug/AndroidManifest.xml
index 399f698..fc248cd 100644
--- a/android/app/src/debug/AndroidManifest.xml
+++ b/android/app/src/debug/AndroidManifest.xml
@@ -4,4 +4,15 @@
          to allow setting breakpoints, to provide hot reload, etc.
     -->
     <uses-permission android:name="android.permission.INTERNET"/>
+
+<!-- 25.12.03 지은 추가 시작 -->
+    <application
+        android:label="smarthelmet_app"
+        android:name="${applicationName}"
+        android:icon="@mipmap/ic_launcher"
+        android:usesCleartextTraffic="true"
+    >
+    </application>
+    <!-- 25.12.03 지은 추가 끝 -->
+
 </manifest>
diff --git a/lib/home_screen_content.dart b/lib/home_screen_content.dart
index 97bac80..a89739d 100644
--- a/lib/home_screen_content.dart
+++ b/lib/home_screen_content.dart
@@ -4,6 +4,9 @@ import 'package:latlong2/latlong.dart';
 import 'dart:ui' as ui;
 import 'package:smarthelmet_app/widgets/custom_header.dart';
 
+//25.12.03 지은 추가
+import 'package:smarthelmet_app/services/locker_api.dart';
+
 class HomeScreenContent extends StatefulWidget {
   const HomeScreenContent({super.key});
 
@@ -23,6 +26,25 @@ class _HomeScreenContentState extends State<HomeScreenContent> {
   final Color _toggleOffTrackColor = const Color(0xFFE0E0E0);
   final Color _toggleOffKnobBorderColor = const Color(0xFFE0E0E0);
 
+// 25.12.03 지은 추가 시작
+  final LockerApi _api = LockerApi();
+  bool _isLoading = false;
+
+Future<void> _runLockerAction(String name, Future<bool> Function() action) async {
+    if (_isLoading) return;
+
+    setState(() => _isLoading = true);
+    
+    // 실제 명령 전송
+    final success = await action();
+    
+    setState(() => _isLoading = false);
+
+    if (!mounted) return;
+  }
+
+  // 25.12.03 지은 추가 끝
+
   int _selectedImageIndex = 0;
 
   static const BoxShadow _cleanShadow = BoxShadow(
@@ -329,7 +351,21 @@ class _HomeScreenContentState extends State<HomeScreenContent> {
                       child: _buildStyledToggleSwitch(
                           'UV LED',
                           _controlToggles['UV LED']!,
-                              (val) => setState(() => _controlToggles['UV LED'] = val))),
+                  // 25.12.03 지은 수정 시작
+                              (val) {
+                                _runLockerAction("UV 제어", () async {
+                                  bool success = await _api.setUV(val);
+
+                                  if (success) {
+                                    setState(() => _controlToggles['UV LED'] = val);
+                                  }
+                                return success;
+                              }
+                            );
+                          },
+                        ),
+                      ),
+                // 25.12.03 지은 수정 끝
                   VerticalDivider(color: _mainBlueColor.withOpacity(0.5), indent: 10, endIndent: 10),
                   Expanded(
                       child: _buildStyledToggleSwitch(
@@ -346,7 +382,22 @@ class _HomeScreenContentState extends State<HomeScreenContent> {
                   Expanded(
                       child: _buildStyledToggleSwitch('FAN',
                           _controlToggles['FAN']!,
-                              (val) => setState(() => _controlToggles['FAN'] = val))),
+                          // 25.12.03 지은 수정 시작
+                              (val) {
+                                print("👉 [디버깅] fan 눌림! 값: $val");
+                                _runLockerAction("FAN 제어", () async {
+                                  print("👉 [디버깅] API 요청 시작...");
+                                bool success = await _api.setFan(val);
+                                
+                                if (success) {
+                                  setState(() => _controlToggles['FAN'] = val);
+                                }
+                                return success;
+                              });
+                            },
+                          // 25.12.03 지은 수정 끝
+                          ),
+                        ),
                 ],
               ),
             )
diff --git a/lib/rental_process_screen.dart b/lib/rental_process_screen.dart
index 18ac8ee..54fa613 100644
--- a/lib/rental_process_screen.dart
+++ b/lib/rental_process_screen.dart
@@ -3,6 +3,9 @@ import 'package:flutter/material.dart';
 import 'package:flutter_map/flutter_map.dart';
 import 'package:latlong2/latlong.dart';
 
+//25.12.03 지은 추가
+import 'package:smarthelmet_app/services/locker_api.dart';
+
 class RentalProcessScreen extends StatefulWidget {
   final String stationName;
 
@@ -26,6 +29,25 @@ class _RentalProcessScreenState extends State<RentalProcessScreen> {
   static const Color _primaryGreen = Color(0xFF4CAF50);
   static const Color _primaryOrange = Color(0xFFFF3D00);
 
+  // 25.12.03 지은 추가 시작
+  final LockerApi _api = LockerApi();
+  bool _isLoading = false;
+
+Future<void> _runLockerAction(String name, Future<bool> Function() action) async {
+    if (_isLoading) return;
+
+    setState(() => _isLoading = true);
+    
+    // 실제 명령 전송
+    final success = await action();
+    
+    setState(() => _isLoading = false);
+
+    if (!mounted) return;
+  }
+
+  // 25.12.03 지은 추가 끝
+
   final PageController _pageController = PageController();
   int _currentPage = 0;
   Timer? _timer;
@@ -241,6 +263,9 @@ class _RentalProcessScreenState extends State<RentalProcessScreen> {
                       height: 68,
                       child: ElevatedButton(
                         onPressed: () {
+                          // 25.12.03 지은 추가
+                          _runLockerAction("잠금 해제", () => _api.unlock());
+                          
                           ScaffoldMessenger.of(context).showSnackBar(
                             const SnackBar(
                               content: Text('문이 열렸습니다! (OPEN 버튼 눌림)'),
diff --git a/lib/services/locker_api.dart b/lib/services/locker_api.dart
new file mode 100644
index 0000000..f8adae0
--- /dev/null
+++ b/lib/services/locker_api.dart
@@ -0,0 +1,59 @@
+import 'dart:convert';
+import 'package:http/http.dart' as http;
+
+class LockerApi {
+  // 안드로이드 에뮬레이터: "http://10.0.2.2:8182"
+  // iOS 시뮬레이터: "http://127.0.0.1:8182"
+  // "http://192.168.0.82:8182"
+  static const String baseUrl = "http://192.168.0.81:8182"; 
+
+  // 명령 전송 공통 함수
+  Future<bool> sendCommand({
+    required int addr, 
+    required int value, 
+    String target = "*"
+  }) async {
+    final url = Uri.parse('$baseUrl/modbus/write');
+    
+    try {
+      final response = await http.post(
+        url,
+        headers: {"Content-Type": "application/json"},
+        body: jsonEncode({
+          "target": target,
+          "unit": 1,
+          "addr": addr,
+          "value": value
+        }),
+      );
+
+      if (response.statusCode == 200) {
+        print("명령 성공: Addr($addr) -> Val($value)");
+        return true;
+      } else {
+        print("명령 실패: ${response.body}");
+        return false;
+      }
+    } catch (e) {
+      print("서버 연결 오류: $e");
+      return false;
+    }
+  }
+
+  // --- [기능별 동작 함수] ---
+
+  // 1. 잠금 해제 (주소: 0x0016 / 값: 1)
+  Future<bool> unlock() async {
+    return await sendCommand(addr: 0x0016, value: 1);
+  }
+
+  // 2. 살균 (UV) 켜기/끄기 (주소: 0x0014 / 값: 1 or 0)
+  Future<bool> setUV(bool isOn) async {
+    return await sendCommand(addr: 0x0014, value: isOn ? 1 : 0);
+  }
+
+  // 3. 건조 (FAN) 켜기/끄기 (주소: 0x0015 / 값: 1 or 0)
+  Future<bool> setFan(bool isOn) async {
+    return await sendCommand(addr: 0x0015, value: isOn ? 1 : 0);
+  }
+}
\ No newline at end of file