diff --git a/barobill_registration/api.php b/barobill_registration/api.php
index 90aa0fe..960efd8 100644
--- a/barobill_registration/api.php
+++ b/barobill_registration/api.php
@@ -3,24 +3,34 @@ header('Content-Type: application/json');
 require_once("../lib/mydb.php");
 
 $method = $_SERVER['REQUEST_METHOD'];
-$pdo = db_connect();
+try {
+    $pdo = db_connect();
 
-switch ($method) {
-    case 'GET':
-        handleGet($pdo);
-        break;
-    case 'POST':
-        handlePost($pdo);
-        break;
-    case 'PUT':
-        handlePut($pdo);
-        break;
-    case 'DELETE':
-        handleDelete($pdo);
-        break;
-    default:
-        echo json_encode(['error' => 'Method not allowed']);
-        break;
+    switch ($method) {
+        case 'GET':
+            handleGet($pdo);
+            break;
+        case 'POST':
+            handlePost($pdo);
+            break;
+        case 'PUT':
+            handlePut($pdo);
+            break;
+        case 'DELETE':
+            handleDelete($pdo);
+            break;
+        default:
+            http_response_code(405);
+            echo json_encode(['error' => 'Method not allowed']);
+            break;
+    }
+} catch (Exception $e) {
+    http_response_code(500);
+    echo json_encode([
+        'error' => 'Backend Error',
+        'message' => $e->getMessage(),
+        'hint' => 'Check if the database table exists by running init_db.php'
+    ]);
 }
 
 function handleGet($pdo) {
@@ -122,4 +132,3 @@ function handleDelete($pdo) {
         echo json_encode(['error' => $e->getMessage()]);
     }
 }
-?>
diff --git a/barobill_registration/index.php b/barobill_registration/index.php
index 17e522a..9c52fb5 100644
--- a/barobill_registration/index.php
+++ b/barobill_registration/index.php
@@ -25,10 +25,18 @@
         }
     </script>
 
-    <!-- React & ReactDOM -->
-    <script crossorigin src="https://unpkg.com/react@18/umd/react.development.js"></script>
-    <script crossorigin src="https://unpkg.com/react-dom@18/umd/react-dom.development.js"></script>
+    <!-- React & ReactDOM (Production) -->
+    <script crossorigin src="https://unpkg.com/react@18/umd/react.production.min.js"></script>
+    <script crossorigin src="https://unpkg.com/react-dom@18/umd/react-dom.production.min.js"></script>
+    
+    <!-- 
+        Note: For production, Babel and Tailwind CDN should be pre-compiled. 
+        Currently kept for rapid development and mobility.
+    -->
+    <!-- Babel for JSX -->
     <script src="https://unpkg.com/@babel/standalone/babel.min.js"></script>
+    
+    <!-- Icons: Lucide -->
     <script src="https://unpkg.com/lucide@latest"></script>
 </head>
 <body class="bg-background text-slate-800 antialiased font-sans">
@@ -187,14 +195,30 @@
             const [loading, setLoading] = useState(true);
             const [activeTab, setActiveTab] = useState('list');
             const [editingMember, setEditingMember] = useState(null);
+            
+            // Auto-fill feature states
+            const [registerKey, setRegisterKey] = useState(0);
+            const [initialTestData, setInitialTestData] = useState({});
 
             const fetchMembers = async () => {
                 setLoading(true);
                 try {
                     const res = await fetch('api.php');
-                    const data = await res.json();
-                    setMembers(data.members || []);
-                } catch (e) { console.error(e); }
+                    const text = await res.text();
+                    try {
+                        const data = JSON.parse(text);
+                        if (data.error) {
+                            alert(`서버 오류: ${data.message || data.error}\n${data.hint || ''}`);
+                        }
+                        setMembers(data.members || []);
+                    } catch (parseError) {
+                        console.error("Invalid JSON response:", text);
+                        alert("서버로부터 올바르지 않은 응답이 수신되었습니다. DB 연결 또는 테이블 생성 여부를 확인해주세요.");
+                    }
+                } catch (e) { 
+                    console.error(e); 
+                    alert("통신 오류가 발생했습니다.");
+                }
                 setLoading(false);
             };
 
@@ -319,12 +343,44 @@
                             </div>
                         ) : (
                             <div className="max-w-3xl animate-in slide-in-from-right-4 duration-300">
-                                <div className="mb-6">
-                                    <h3 className="text-xl font-bold text-slate-900">신규 회원사 가입</h3>
-                                    <p className="text-xs text-slate-400">입력된 정보로 바로빌 RegistCorp API가 호출됩니다.</p>
+                                <div className="mb-6 flex justify-between items-center">
+                                    <div>
+                                        <h3 className="text-xl font-bold text-slate-900">신규 회원사 가입</h3>
+                                        <p className="text-xs text-slate-400">입력된 정보로 바로빌 RegistCorp API가 호출됩니다.</p>
+                                    </div>
+                                    <button 
+                                        onClick={() => {
+                                            const randomId = Math.random().toString(36).substring(2, 8);
+                                            const randomBiz = `123-45-${Math.floor(10000 + Math.random() * 90000)}`;
+                                            const testData = {
+                                                bizNo: randomBiz,
+                                                corpName: `테스트기업_${randomId}`,
+                                                ceoName: '홍길동',
+                                                addr: '서울특별시 강남구 테헤란로 123',
+                                                bizType: '서비스',
+                                                bizClass: '소프트웨어',
+                                                id: `test_${randomId}`,
+                                                pwd: 'password123!',
+                                                managerName: '김철수',
+                                                managerHP: '010-1234-5678',
+                                                managerEmail: `test_${randomId}@example.com`
+                                            };
+                                            // Trigger a custom event or use a state update mechanism 
+                                            // provided by the child component if available. 
+                                            // Since we're in the parent, we'll pass it down via a key or ref if needed,
+                                            // but for simpler implementation, we'll use a unique key to reset the form component with new initialData.
+                                            setRegisterKey(prev => prev + 1);
+                                            setInitialTestData(testData);
+                                        }}
+                                        className="flex items-center gap-2 px-4 py-2 bg-amber-100 text-amber-700 rounded-lg hover:bg-amber-200 transition-all font-bold text-xs"
+                                        title="랜덤 테스트 데이터 입력"
+                                    >
+                                        <i data-lucide="zap" className="w-4 h-4 fill-amber-500"></i>
+                                        자동 완성
+                                    </button>
                                 </div>
                                 <div className="bg-white rounded-card p-6 shadow-sm border border-slate-100">
-                                    <MemberForm onSubmit={handleRegister} />
+                                    <MemberForm key={registerKey} initialData={initialTestData} onSubmit={handleRegister} />
                                 </div>
                             </div>
                         )}
diff --git a/barobill_registration/init_db.php b/barobill_registration/init_db.php
index ea5bf3e..6773c97 100644
--- a/barobill_registration/init_db.php
+++ b/barobill_registration/init_db.php
@@ -9,4 +9,3 @@ try {
 } catch (Exception $e) {
     echo "Error: " . $e->getMessage();
 }
-?>
