diff --git a/frontend/components/screen/CopyScreenModal.tsx b/frontend/components/screen/CopyScreenModal.tsx
index 8bbe80a6..fa294e52 100644
--- a/frontend/components/screen/CopyScreenModal.tsx
+++ b/frontend/components/screen/CopyScreenModal.tsx
@@ -51,9 +51,9 @@ const escapeRegExp = (str: string): string => {
 };
 
 interface LinkedModalScreen {
-  screenId: number;
-  screenName: string;
-  screenCode: string;
+  screen_id: number;
+  screen_name: string;
+  screen_code: string;
   newScreenName?: string;
   newScreenCode?: string;
 }
@@ -237,7 +237,7 @@ export default function CopyScreenModal({
       setLinkedScreens((prev) =>
         prev.map((screen) => ({
           ...screen,
-          newScreenName: applyBulkRename(screen.screenName),
+          newScreenName: applyBulkRename(screen.screen_name),
         }))
       );
     } else {
@@ -247,7 +247,7 @@ export default function CopyScreenModal({
       setLinkedScreens((prev) =>
         prev.map((screen) => ({
           ...screen,
-          newScreenName: screen.screenName,
+          newScreenName: screen.screen_name,
         }))
       );
     }
@@ -344,7 +344,7 @@ export default function CopyScreenModal({
       setLinkedScreens(
         linked.map((screen) => ({
           ...screen,
-          newScreenName: `${screen.screenName} (복사본)`,
+          newScreenName: `${screen.screen_name} (복사본)`,
         }))
       );
 
@@ -394,7 +394,7 @@ export default function CopyScreenModal({
 
         setLinkedScreens(updatedLinkedScreens);
         console.log("✅ 모달 화면 코드 할당 완료:", updatedLinkedScreens.map(s => ({
-          name: s.screenName,
+          name: s.screen_name,
           code: s.newScreenCode
         })));
       }
@@ -408,14 +408,14 @@ export default function CopyScreenModal({
   const updateLinkedScreenName = (screenId: number, newName: string) => {
     setLinkedScreens((prev) =>
       prev.map((screen) =>
-        screen.screenId === screenId ? { ...screen, newScreenName: newName } : screen
+        screen.screen_id === screenId ? { ...screen, newScreenName: newName } : screen
       )
     );
   };
 
   // 연결된 화면 제거 (복사하지 않음)
   const removeLinkedScreen = (screenId: number) => {
-    setLinkedScreens((prev) => prev.filter((screen) => screen.screenId !== screenId));
+    setLinkedScreens((prev) => prev.filter((screen) => screen.screen_id !== screenId));
   };
 
   // 화면명 일괄 변경 적용
@@ -448,8 +448,8 @@ export default function CopyScreenModal({
         preview: applyBulkRename(sourceScreen.screen_name), // (복사본) 없음
       },
       modals: linkedScreens.map((screen) => ({
-        original: screen.screenName,
-        preview: applyBulkRename(screen.screenName),
+        original: screen.screen_name,
+        preview: applyBulkRename(screen.screen_name),
       })),
     };
   };
@@ -548,11 +548,11 @@ export default function CopyScreenModal({
     // 연결된 화면들의 이름 검증
     for (const linked of linkedScreens) {
       if (!linked.newScreenName?.trim()) {
-        toast.error(`"${linked.screenName}" 모달 화면의 새 이름을 입력해주세요.`);
+        toast.error(`"${linked.screen_name}" 모달 화면의 새 이름을 입력해주세요.`);
         return;
       }
       if (!linked.newScreenCode?.trim()) {
-        toast.error(`"${linked.screenName}" 모달 화면의 코드가 생성되지 않았습니다.`);
+        toast.error(`"${linked.screen_name}" 모달 화면의 코드가 생성되지 않았습니다.`);
         return;
       }
     }
@@ -599,7 +599,7 @@ export default function CopyScreenModal({
           description: description.trim(),
         },
         modalScreens: linkedScreens.map((screen) => ({
-          sourceScreenId: screen.screenId,
+          sourceScreenId: screen.screen_id,
           screenName: screen.newScreenName!.trim(),
           screenCode: screen.newScreenCode!.trim(),
         })),
@@ -1785,11 +1785,11 @@ export default function CopyScreenModal({
               </div>
               <div className="space-y-2 max-h-[150px] overflow-y-auto">
                 {linkedScreens.map((linked) => (
-                  <div key={linked.screenId} className="flex items-center justify-between text-xs bg-muted rounded p-2">
+                  <div key={linked.screen_id} className="flex items-center justify-between text-xs bg-muted rounded p-2">
                     <div className="flex-1 min-w-0">
                       <Input
                         value={linked.newScreenName || ""}
-                        onChange={(e) => updateLinkedScreenName(linked.screenId, e.target.value)}
+                        onChange={(e) => updateLinkedScreenName(linked.screen_id, e.target.value)}
                         className="h-7 text-xs"
                         placeholder="모달 화면명"
                       />
@@ -1798,7 +1798,7 @@ export default function CopyScreenModal({
                       variant="ghost"
                       size="icon"
                       className="h-7 w-7 ml-1 text-destructive"
-                      onClick={() => removeLinkedScreen(linked.screenId)}
+                      onClick={() => removeLinkedScreen(linked.screen_id)}
                     >
                       <Trash2 className="h-3 w-3" />
                     </Button>
diff --git a/frontend/components/screen/EditModal.tsx b/frontend/components/screen/EditModal.tsx
index c7ef75c5..70b57e3f 100644
--- a/frontend/components/screen/EditModal.tsx
+++ b/frontend/components/screen/EditModal.tsx
@@ -264,7 +264,7 @@ export const EditModal: React.FC<EditModalProps> = ({ className }) => {
       let detailTableName = eventTableName;
       if (!detailTableName) {
         const screenInfo = await screenApi.getScreen(targetScreenId);
-        detailTableName = screenInfo?.table_name ?? screenInfo?.tableName;
+        detailTableName = screenInfo?.table_name;
       }
 
       if (!detailTableName) {
diff --git a/frontend/components/screen/ScreenDesigner.tsx b/frontend/components/screen/ScreenDesigner.tsx
index ed3565f3..553a2b6f 100644
--- a/frontend/components/screen/ScreenDesigner.tsx
+++ b/frontend/components/screen/ScreenDesigner.tsx
@@ -1350,7 +1350,7 @@ export default function ScreenDesigner({
         const tableListResponse = await tableManagementApi.getTableList();
         const currentTable =
           tableListResponse.success && tableListResponse.data
-            ? tableListResponse.data.find((t) => t.tableName === tableName)
+            ? tableListResponse.data.find((t) => t.table_name === tableName)
             : null;
         const tableLabel = currentTable?.display_name || tableName;
 
@@ -1359,11 +1359,11 @@ export default function ScreenDesigner({
 
         const columns: ColumnInfo[] = (columnsResponse || []).map((col: any) => {
           // widgetType 결정: inputType(entity 등) > webType > widget_type
-          const inputType = col.inputType || col.input_type;
-          const widgetType = inputType || col.widgetType || col.widget_type || col.webType || col.web_type;
+          const inputType = col.input_type;
+          const widgetType = inputType || col.widget_type || col.web_type;
 
           // detailSettings 파싱 (문자열이면 JSON 파싱)
-          let detailSettings = col.detailSettings || col.detail_settings;
+          let detailSettings = col.detail_settings;
           if (typeof detailSettings === "string") {
             // JSON 형식인 경우에만 파싱 시도 (중괄호로 시작하는 경우)
             if (detailSettings.trim().startsWith("{")) {
@@ -1382,33 +1382,33 @@ export default function ScreenDesigner({
           // 엔티티 타입 디버깅
           if (inputType === "entity" || widgetType === "entity") {
             console.log("🔍 엔티티 컬럼 감지:", {
-              columnName: col.columnName || col.column_name,
+              columnName: col.column_name,
               inputType,
               widgetType,
               detailSettings,
-              referenceTable: detailSettings?.referenceTable || col.referenceTable || col.reference_table,
+              referenceTable: detailSettings?.referenceTable || col.reference_table,
             });
           }
 
           return {
-            tableName: col.tableName || tableName,
-            columnName: col.columnName || col.column_name,
-            columnLabel: col.displayName || col.columnLabel || col.column_label || col.columnName || col.column_name,
-            dataType: col.dataType || col.data_type || col.dbType,
-            webType: col.webType || col.web_type,
+            tableName: col.table_name || tableName,
+            columnName: col.column_name,
+            columnLabel: col.display_name || col.column_label || col.column_name,
+            dataType: col.data_type || col.db_type,
+            webType: col.web_type,
             input_type: inputType,
             inputType: inputType,
             widgetType,
-            isNullable: col.isNullable || col.is_nullable,
-            required: col.required !== undefined ? col.required : col.isNullable === "NO" || col.is_nullable === "NO",
-            columnDefault: col.columnDefault || col.column_default,
-            characterMaximumLength: col.characterMaximumLength || col.character_maximum_length,
-            codeCategory: col.codeCategory || col.code_category,
-            codeValue: col.codeValue || col.code_value,
+            isNullable: col.is_nullable,
+            required: col.required !== undefined ? col.required : col.is_nullable === "NO",
+            columnDefault: col.column_default,
+            characterMaximumLength: col.character_maximum_length,
+            codeCategory: col.code_category,
+            codeValue: col.code_value,
             // 엔티티 타입용 참조 테이블 정보 (detailSettings에서 추출)
-            referenceTable: detailSettings?.referenceTable || col.referenceTable || col.reference_table,
-            referenceColumn: detailSettings?.referenceColumn || col.referenceColumn || col.reference_column,
-            displayColumn: detailSettings?.displayColumn || col.displayColumn || col.display_column,
+            referenceTable: detailSettings?.referenceTable || col.reference_table,
+            referenceColumn: detailSettings?.referenceColumn || col.reference_column,
+            displayColumn: detailSettings?.displayColumn || col.display_column,
             // detailSettings 전체 보존 (V2 컴포넌트용)
             detailSettings,
           };
@@ -1455,7 +1455,7 @@ export default function ScreenDesigner({
         const tableListResponse = await tableManagementApi.getTableList();
         const currentTable =
           tableListResponse.success && tableListResponse.data
-            ? tableListResponse.data.find((t: any) => (t.tableName || t.table_name) === tableName)
+            ? tableListResponse.data.find((t: any) => t.table_name === tableName)
             : null;
         const tableLabel = currentTable?.display_name || currentTable?.table_label || tableName;
 
@@ -1463,10 +1463,10 @@ export default function ScreenDesigner({
         const columnsResponse = await tableTypeApi.getColumns(tableName, true);
 
         const columns: ColumnInfo[] = (columnsResponse || []).map((col: any) => {
-          const inputType = col.inputType || col.input_type;
-          const widgetType = inputType || col.widgetType || col.widget_type || col.webType || col.web_type;
+          const inputType = col.input_type;
+          const widgetType = inputType || col.widget_type || col.web_type;
 
-          let detailSettings = col.detailSettings || col.detail_settings;
+          let detailSettings = col.detail_settings;
           if (typeof detailSettings === "string") {
             try {
               detailSettings = JSON.parse(detailSettings);
@@ -1476,23 +1476,23 @@ export default function ScreenDesigner({
           }
 
           return {
-            tableName: col.tableName || tableName,
-            columnName: col.columnName || col.column_name,
-            columnLabel: col.displayName || col.columnLabel || col.column_label || col.columnName || col.column_name,
-            dataType: col.dataType || col.data_type || col.dbType,
-            webType: col.webType || col.web_type,
+            tableName: col.table_name || tableName,
+            columnName: col.column_name,
+            columnLabel: col.display_name || col.column_label || col.column_name,
+            dataType: col.data_type || col.db_type,
+            webType: col.web_type,
             input_type: inputType,
             inputType: inputType,
             widgetType,
-            isNullable: col.isNullable || col.is_nullable,
-            required: col.required !== undefined ? col.required : col.isNullable === "NO" || col.is_nullable === "NO",
-            columnDefault: col.columnDefault || col.column_default,
-            characterMaximumLength: col.characterMaximumLength || col.character_maximum_length,
-            codeCategory: col.codeCategory || col.code_category,
-            codeValue: col.codeValue || col.code_value,
-            referenceTable: detailSettings?.referenceTable || col.referenceTable || col.reference_table,
-            referenceColumn: detailSettings?.referenceColumn || col.referenceColumn || col.reference_column,
-            displayColumn: detailSettings?.displayColumn || col.displayColumn || col.display_column,
+            isNullable: col.is_nullable,
+            required: col.required !== undefined ? col.required : col.is_nullable === "NO",
+            columnDefault: col.column_default,
+            characterMaximumLength: col.character_maximum_length,
+            codeCategory: col.code_category,
+            codeValue: col.code_value,
+            referenceTable: detailSettings?.referenceTable || col.reference_table,
+            referenceColumn: detailSettings?.referenceColumn || col.reference_column,
+            displayColumn: detailSettings?.displayColumn || col.display_column,
             detailSettings,
           };
         });
@@ -2174,8 +2174,8 @@ export default function ScreenDesigner({
             if (Array.isArray(columns)) {
               columnLabelMap[tableName] = {};
               columns.forEach((col: any) => {
-                const colName = col.columnName || col.column_name || col.name;
-                const colLabel = col.displayName || col.columnLabel || col.column_label || colName;
+                const colName = col.column_name || col.name;
+                const colLabel = col.display_name || col.column_label || colName;
                 if (colName) {
                   columnLabelMap[tableName][colName] = colLabel;
                 }
diff --git a/frontend/components/screen/ScreenList.tsx b/frontend/components/screen/ScreenList.tsx
index 93c140a9..c8a7be17 100644
--- a/frontend/components/screen/ScreenList.tsx
+++ b/frontend/components/screen/ScreenList.tsx
@@ -273,12 +273,12 @@ export default function ScreenList({ onScreenSelect, selectedScreen, onDesignScr
           
           // 최고 관리자이고 특정 회사를 선택한 경우
           if (isSuperAdmin && selectedCompanyCode !== "all") {
-            params.companyCode = selectedCompanyCode;
+            params.company_code = selectedCompanyCode;
           }
 
           // 그룹 필터
           if (selectedGroupId !== "all") {
-            params.groupId = selectedGroupId;
+            params.group_id = selectedGroupId;
           }
 
           console.log("🔍 화면 목록 API 호출:", params); // 디버깅용
@@ -325,9 +325,9 @@ export default function ScreenList({ onScreenSelect, selectedScreen, onDesignScr
       
       // 최고 관리자이고 특정 회사를 선택한 경우
       if (isSuperAdmin && selectedCompanyCode !== "all") {
-        params.companyCode = selectedCompanyCode;
+        params.company_code = selectedCompanyCode;
       }
-      
+
       const resp = await screenApi.getScreens(params);
       setScreens(resp.data || []);
       setTotalPages(Math.max(1, Math.ceil((resp.total || 0) / 20)));
@@ -740,7 +740,7 @@ export default function ScreenList({ onScreenSelect, selectedScreen, onDesignScr
                 <SelectItem value="ungrouped">미분류</SelectItem>
                 {groups.map((group) => (
                   <SelectItem key={group.id} value={String(group.id)}>
-                    {group.groupName}
+                    {group.group_name}
                   </SelectItem>
                 ))}
               </SelectContent>
diff --git a/frontend/components/screen/ScreenRelationView.tsx b/frontend/components/screen/ScreenRelationView.tsx
index 9f400b1a..274b2c61 100644
--- a/frontend/components/screen/ScreenRelationView.tsx
+++ b/frontend/components/screen/ScreenRelationView.tsx
@@ -189,18 +189,18 @@ export function ScreenRelationView({ screen }: ScreenRelationViewProps) {
                   className="flex items-center gap-2 p-2 rounded-md bg-muted/50 text-sm"
                 >
                   <div className="flex items-center gap-1">
-                    <span className="font-mono text-xs">{join.sourceTable}</span>
+                    <span className="font-mono text-xs">{join.save_table}</span>
                     <span className="text-muted-foreground">.</span>
-                    <span className="font-mono text-xs text-primary">{join.sourceColumn}</span>
+                    <span className="font-mono text-xs text-primary">{join.save_column}</span>
                   </div>
                   <ArrowRight className="h-3 w-3 text-muted-foreground" />
                   <div className="flex items-center gap-1">
-                    <span className="font-mono text-xs">{join.targetTable}</span>
+                    <span className="font-mono text-xs">{join.join_table}</span>
                     <span className="text-muted-foreground">.</span>
-                    <span className="font-mono text-xs text-emerald-600">{join.targetColumn}</span>
+                    <span className="font-mono text-xs text-emerald-600">{join.join_column}</span>
                   </div>
                   <Badge variant="outline" className="ml-auto text-xs">
-                    {join.joinType}
+                    {join.join_type}
                   </Badge>
                 </div>
               ))}
@@ -231,14 +231,14 @@ export function ScreenRelationView({ screen }: ScreenRelationViewProps) {
                   className="flex items-center gap-2 p-2 rounded-md bg-muted/50 text-sm"
                 >
                   <Monitor className="h-4 w-4 text-primary" />
-                  <span className="truncate">{flow.flowName || "이름 없음"}</span>
+                  <span className="truncate">{flow.flow_label || "이름 없음"}</span>
                   <ArrowRight className="h-3 w-3 text-muted-foreground" />
                   <Monitor className="h-4 w-4 text-emerald-500" />
                   <span className="text-muted-foreground truncate">
-                    화면 #{flow.targetScreenId}
+                    화면 #{flow.target_screen_id}
                   </span>
                   <Badge variant="outline" className="ml-auto text-xs">
-                    {flow.flowType}
+                    {flow.flow_type}
                   </Badge>
                 </div>
               ))}
@@ -269,11 +269,11 @@ export function ScreenRelationView({ screen }: ScreenRelationViewProps) {
                   className="flex items-center gap-2 p-2 rounded-md bg-muted/50 text-sm"
                 >
                   <Table className="h-4 w-4 text-muted-foreground" />
-                  <span className="font-mono text-xs">{relation.parentTable}</span>
+                  <span className="font-mono text-xs">{screen.table_name}</span>
                   <ArrowRight className="h-3 w-3 text-muted-foreground" />
-                  <span className="font-mono text-xs">{relation.childTable}</span>
+                  <span className="font-mono text-xs">{relation.table_name}</span>
                   <Badge variant="outline" className="ml-auto text-xs">
-                    {relation.relationType}
+                    {relation.relation_type}
                   </Badge>
                 </div>
               ))}
diff --git a/frontend/lib/api/data.ts b/frontend/lib/api/data.ts
index e1f14b14..206a0607 100644
--- a/frontend/lib/api/data.ts
+++ b/frontend/lib/api/data.ts
@@ -61,10 +61,10 @@ export const dataApi = {
     try {
       const params: any = {};
       if (enableEntityJoin) {
-        params.enableEntityJoin = true;
+        params.enable_entity_join = true;
       }
       if (groupByColumns.length > 0) {
-        params.groupByColumns = JSON.stringify(groupByColumns);
+        params.group_by_columns = JSON.stringify(groupByColumns);
       }
       
       console.log("🌐 [dataApi.getRecordDetail] API 호출:", {
@@ -123,14 +123,14 @@ export const dataApi = {
   ): Promise<any[]> => {
     const response = await apiClient.get(`/data/join`, {
       params: {
-        leftTable,
-        rightTable,
-        leftColumn,
-        rightColumn,
-        leftValue,
-        dataFilter: dataFilter ? JSON.stringify(dataFilter) : undefined,
-        enableEntityJoin: enableEntityJoin ?? true,
-        displayColumns: displayColumns ? JSON.stringify(displayColumns) : undefined, // 🆕 표시 컬럼 전달
+        left_table: leftTable,
+        right_table: rightTable,
+        left_column: leftColumn,
+        right_column: rightColumn,
+        left_value: leftValue,
+        data_filter: dataFilter ? JSON.stringify(dataFilter) : undefined,
+        enable_entity_join: enableEntityJoin ?? true,
+        display_columns: displayColumns ? JSON.stringify(displayColumns) : undefined, // 🆕 표시 컬럼 전달
         deduplication: deduplication ? JSON.stringify(deduplication) : undefined, // 🆕 중복 제거 설정 전달
       },
     });
@@ -215,7 +215,7 @@ export const dataApi = {
     try {
       const params: any = {};
       if (enableEntityJoin) {
-        params.enableEntityJoin = "true";
+        params.enable_entity_join = "true";
       }
       const response = await apiClient.get(`/data/${tableName}/${id}`, { params });
       return response.data; // { success: true, data: ... } 형식 그대로 반환
@@ -249,10 +249,10 @@ export const dataApi = {
       });
 
       const requestBody = {
-        tableName,
+        table_name: tableName,
         parentKeys,
         records,
-        deleteOrphans: options?.deleteOrphans ?? true, // 기본값: true (기존 동작 유지)
+        delete_orphans: options?.deleteOrphans ?? true, // 기본값: true (기존 동작 유지)
       };
       console.log("📦 [dataApi.upsertGroupedRecords] 요청 본문 (JSON):", JSON.stringify(requestBody, null, 2));
 
diff --git a/frontend/lib/api/dataflowSave.ts b/frontend/lib/api/dataflowSave.ts
index 49007659..a51c5607 100644
--- a/frontend/lib/api/dataflowSave.ts
+++ b/frontend/lib/api/dataflowSave.ts
@@ -64,7 +64,7 @@ export const loadDataflowRelationship = async (diagramId: number) => {
     let relationshipsData;
 
     // Case 1: 현재 구조 - relationships 자체가 관계 데이터
-    if (diagram.relationships && (diagram.relationships.connection_type || diagram.relationships.connectionType)) {
+    if (diagram.relationships && diagram.relationships.connection_type) {
       relationshipsData = diagram.relationships;
       console.log("✅ 현재 구조 감지 (relationships 직접):", relationshipsData);
     }
@@ -85,22 +85,22 @@ export const loadDataflowRelationship = async (diagramId: number) => {
       // 기존 구조를 redesigned 구조로 변환
       relationshipsData = {
         description: firstRelation.note || "",
-        connectionType: firstRelation.connection_type || firstRelation.connectionType || "data_save",
-        fromConnection: { id: 0, name: "메인 데이터베이스 (현재 시스템)" }, // 기본값
-        toConnection: { id: 0, name: "메인 데이터베이스 (현재 시스템)" }, // 기본값
-        fromTable: firstRelation.from_table || firstRelation.fromTable,
-        toTable: firstRelation.to_table || firstRelation.toTable,
-        actionType: "insert", // 기본값
-        controlConditions: [],
-        actionConditions: [],
-        fieldMappings: [],
+        connection_type: firstRelation.connection_type || "data_save",
+        from_connection: { id: 0, name: "메인 데이터베이스 (현재 시스템)" }, // 기본값
+        to_connection: { id: 0, name: "메인 데이터베이스 (현재 시스템)" }, // 기본값
+        from_table: firstRelation.from_table,
+        to_table: firstRelation.to_table,
+        action_type: "insert", // 기본값
+        control_conditions: [],
+        action_conditions: [],
+        field_mappings: [],
       };
 
       // 기존 control 및 plan 데이터를 변환
       if (diagram.control && diagram.control.length > 0) {
         const control = diagram.control.find((c) => c.id === firstRelation.id);
         if (control && control.conditions) {
-          relationshipsData.controlConditions = control.conditions;
+          relationshipsData.control_conditions = control.conditions;
         }
       }
 
@@ -108,9 +108,9 @@ export const loadDataflowRelationship = async (diagramId: number) => {
         const plan = diagram.plan.find((p) => p.id === firstRelation.id);
         if (plan && plan.actions && plan.actions.length > 0) {
           const firstAction = plan.actions[0];
-          relationshipsData.actionType = firstAction.action_type || firstAction.actionType || "insert";
-          relationshipsData.fieldMappings = firstAction.field_mappings || firstAction.fieldMappings || [];
-          relationshipsData.actionConditions = firstAction.action_conditions || firstAction.conditions || [];
+          relationshipsData.action_type = firstAction.action_type || "insert";
+          relationshipsData.field_mappings = firstAction.field_mappings || [];
+          relationshipsData.action_conditions = firstAction.action_conditions || firstAction.conditions || [];
         }
       }
     }
@@ -121,18 +121,18 @@ export const loadDataflowRelationship = async (diagramId: number) => {
       // 현재 DB에 저장된 구조 처리 (relationships 객체에 모든 데이터가 있음)
       relationshipsData = {
         description: diagram.relationships.description || "",
-        connection_type: diagram.relationships.connection_type || diagram.relationships.connectionType || "data_save",
-        from_connection: diagram.relationships.from_connection || diagram.relationships.fromConnection || { id: 0, name: "메인 데이터베이스 (현재 시스템)" },
-        to_connection: diagram.relationships.to_connection || diagram.relationships.toConnection || { id: 0, name: "메인 데이터베이스 (현재 시스템)" },
-        from_table: diagram.relationships.from_table || diagram.relationships.fromTable,
-        to_table: diagram.relationships.to_table || diagram.relationships.toTable,
-        action_type: diagram.relationships.action_type || diagram.relationships.actionType || "insert",
-        control_conditions: diagram.relationships.control_conditions || diagram.relationships.controlConditions || [],
-        action_conditions: diagram.relationships.action_conditions || diagram.relationships.actionConditions || [],
-        field_mappings: diagram.relationships.field_mappings || diagram.relationships.fieldMappings || [],
+        connection_type: diagram.relationships.connection_type || "data_save",
+        from_connection: diagram.relationships.from_connection || { id: 0, name: "메인 데이터베이스 (현재 시스템)" },
+        to_connection: diagram.relationships.to_connection || { id: 0, name: "메인 데이터베이스 (현재 시스템)" },
+        from_table: diagram.relationships.from_table,
+        to_table: diagram.relationships.to_table,
+        action_type: diagram.relationships.action_type || "insert",
+        control_conditions: diagram.relationships.control_conditions || [],
+        action_conditions: diagram.relationships.action_conditions || [],
+        field_mappings: diagram.relationships.field_mappings || [],
         // 🔧 멀티 액션 그룹 데이터 로드
-        action_groups: diagram.relationships.action_groups || diagram.relationships.actionGroups || null,
-        external_call_config: diagram.relationships.external_call_config || diagram.relationships.externalCallConfig,
+        action_groups: diagram.relationships.action_groups || null,
+        external_call_config: diagram.relationships.external_call_config,
       };
       console.log("✅ 현재 DB 구조 처리 완료:", relationshipsData);
     } else {
@@ -146,19 +146,19 @@ export const loadDataflowRelationship = async (diagramId: number) => {
       diagramId: diagram.diagram_id, // 🔧 수정 모드를 위한 diagramId 추가
       relationshipName: diagram.diagram_name,
       description: relationshipsData.description || diagram.description || "", // 🔧 diagram.description도 확인
-      connectionType: relationshipsData.connection_type || relationshipsData.connectionType || "data_save",
-      fromConnection: relationshipsData.from_connection || relationshipsData.fromConnection || { id: 0, name: "메인 데이터베이스 (현재 시스템)" },
-      toConnection: relationshipsData.to_connection || relationshipsData.toConnection || { id: 0, name: "메인 데이터베이스 (현재 시스템)" },
-      fromTable: relationshipsData.from_table || relationshipsData.fromTable,
-      toTable: relationshipsData.to_table || relationshipsData.toTable,
-      actionType: relationshipsData.action_type || relationshipsData.actionType || "insert",
-      controlConditions: relationshipsData.control_conditions || relationshipsData.controlConditions || [],
-      actionConditions: relationshipsData.action_conditions || relationshipsData.actionConditions || [],
-      fieldMappings: relationshipsData.field_mappings || relationshipsData.fieldMappings || [],
+      connectionType: relationshipsData.connection_type || "data_save",
+      fromConnection: relationshipsData.from_connection || { id: 0, name: "메인 데이터베이스 (현재 시스템)" },
+      toConnection: relationshipsData.to_connection || { id: 0, name: "메인 데이터베이스 (현재 시스템)" },
+      fromTable: relationshipsData.from_table,
+      toTable: relationshipsData.to_table,
+      actionType: relationshipsData.action_type || "insert",
+      controlConditions: relationshipsData.control_conditions || [],
+      actionConditions: relationshipsData.action_conditions || [],
+      fieldMappings: relationshipsData.field_mappings || [],
       // 🔧 멀티 액션 그룹 데이터 포함
-      actionGroups: relationshipsData.action_groups || relationshipsData.actionGroups,
+      actionGroups: relationshipsData.action_groups,
       // 🔧 외부호출 설정 데이터 포함
-      externalCallConfig: relationshipsData.external_call_config || relationshipsData.externalCallConfig,
+      externalCallConfig: relationshipsData.external_call_config,
     };
 
     console.log("✨ 변환된 로드 데이터:", loadedData);
diff --git a/frontend/lib/api/dynamicForm.ts b/frontend/lib/api/dynamicForm.ts
index 3e0146a4..7e720036 100644
--- a/frontend/lib/api/dynamicForm.ts
+++ b/frontend/lib/api/dynamicForm.ts
@@ -247,8 +247,8 @@ export class DynamicFormApi {
       page?: number;
       size?: number;
       search?: string;
-      sortBy?: string;
-      sortOrder?: "asc" | "desc";
+      sort_by?: string;
+      sort_order?: "asc" | "desc";
     },
   ): Promise<
     ApiResponse<{
@@ -433,12 +433,12 @@ export class DynamicFormApi {
     tableName: string,
     params?: {
       page?: number;
-      pageSize?: number;
+      page_size?: number;
       search?: string;
-      sortBy?: string;
-      sortOrder?: "asc" | "desc";
+      sort_by?: string;
+      sort_order?: "asc" | "desc";
       filters?: Record<string, any>;
-      autoFilter?: {
+      auto_filter?: {
         enabled: boolean;
         filter_column?: string;
         user_field?: string;
@@ -452,8 +452,8 @@ export class DynamicFormApi {
       // pageSize를 size로 변환 (백엔드 파라미터명 호환)
       const requestParams = {
         ...params,
-        size: params?.pageSize || params?.size || 100, // 기본값 100
-        autoFilter: params?.autoFilter ?? {
+        size: params?.page_size || params?.size || 100, // 기본값 100
+        auto_filter: params?.auto_filter ?? {
           enabled: true,
           filter_column: "company_code",
           user_field: "company_code",
@@ -533,10 +533,10 @@ export class DynamicFormApi {
    * @returns 업로드 결과
    */
   static async uploadExcelData(payload: {
-    tableName: string;
+    table_name: string;
     data: any[];
-    uploadMode: "insert" | "update" | "upsert";
-    keyColumn?: string;
+    upload_mode: "insert" | "update" | "upsert";
+    key_column?: string;
   }): Promise<ApiResponse<any>> {
     try {
       console.log("📤 엑셀 업로드 요청:", payload);
diff --git a/frontend/lib/api/file.ts b/frontend/lib/api/file.ts
index 3e7390f9..79726ea9 100644
--- a/frontend/lib/api/file.ts
+++ b/frontend/lib/api/file.ts
@@ -22,7 +22,7 @@ export interface FileUploadResponse {
 export interface FileDownloadParams {
   fileId: string;
   server_filename: string;
-  originalName: string;
+  original_name: string;
 }
 
 /**
@@ -89,7 +89,7 @@ export const downloadFile = async (params: FileDownloadParams): Promise<void> =>
     const response = await apiClient.get(`/files/download/${params.fileId}`, {
       params: {
         server_filename: params.server_filename,
-        originalName: params.originalName,
+        original_name: params.original_name,
       },
       responseType: "blob", // 파일 다운로드를 위해 blob 타입으로 설정
     });
@@ -103,7 +103,7 @@ export const downloadFile = async (params: FileDownloadParams): Promise<void> =>
     // 다운로드 링크 생성 및 클릭
     const link = document.createElement("a");
     link.href = url;
-    link.download = params.originalName;
+    link.download = params.original_name;
     document.body.appendChild(link);
     link.click();
 
diff --git a/frontend/lib/api/screen.ts b/frontend/lib/api/screen.ts
index c0e564cc..5e9d688b 100644
--- a/frontend/lib/api/screen.ts
+++ b/frontend/lib/api/screen.ts
@@ -358,7 +358,7 @@ export const screenApi = {
   // 연결된 모달 화면 감지
   detectLinkedModals: async (
     screenId: number,
-  ): Promise<Array<{ screenId: number; screenName: string; screenCode: string }>> => {
+  ): Promise<Array<{ screen_id: number; screen_name: string; screen_code: string }>> => {
     const response = await apiClient.get(`/screen-management/screens/${screenId}/linked-modals`);
     return response.data.data || [];
   },
diff --git a/frontend/lib/registry/components/v2-file-upload/FileUploadComponent.tsx b/frontend/lib/registry/components/v2-file-upload/FileUploadComponent.tsx
index dedd6194..5f6638b7 100644
--- a/frontend/lib/registry/components/v2-file-upload/FileUploadComponent.tsx
+++ b/frontend/lib/registry/components/v2-file-upload/FileUploadComponent.tsx
@@ -823,8 +823,8 @@ const FileUploadComponent: React.FC<FileUploadComponentProps> = ({
     try {
       await downloadFile({
         fileId: file.objid,
-        serverFilename: file.savedFileName,
-        originalName: file.realFileName,
+        server_filename: file.savedFileName,
+        original_name: file.realFileName,
       });
       toast.success(`${file.realFileName} 다운로드 완료`);
     } catch (error) {
@@ -934,7 +934,7 @@ const FileUploadComponent: React.FC<FileUploadComponentProps> = ({
         // 🔑 previewUrl 상대 경로 대신 apiClient를 사용하여 Docker 환경에서도 정상 동작
         const response = await apiClient.get(`/files/preview/${file.objid}`, {
           params: {
-            serverFilename: file.savedFileName,
+            server_filename: file.savedFileName,
           },
           responseType: "blob",
         });
diff --git a/frontend/lib/registry/components/v2-split-panel-layout/SplitPanelLayoutConfigPanel.tsx b/frontend/lib/registry/components/v2-split-panel-layout/SplitPanelLayoutConfigPanel.tsx
index 517fd5be..d3e9c240 100644
--- a/frontend/lib/registry/components/v2-split-panel-layout/SplitPanelLayoutConfigPanel.tsx
+++ b/frontend/lib/registry/components/v2-split-panel-layout/SplitPanelLayoutConfigPanel.tsx
@@ -1656,7 +1656,7 @@ export const SplitPanelLayoutConfigPanel: React.FC<SplitPanelLayoutConfigPanelPr
         required: col.required !== undefined ? col.required : col.is_nullable === "NO",
         columnDefault: col.column_default,
         characterMaximumLength: col.character_maximum_length,
-        isPrimaryKey: col.isPrimaryKey || false, // PK 여부 추가
+        isPrimaryKey: col.is_primary_key || false, // PK 여부 추가
         codeCategory: col.code_category,
         codeValue: col.code_value,
         referenceTable: col.reference_table, // 🆕 참조 테이블
@@ -1776,8 +1776,8 @@ export const SplitPanelLayoutConfigPanel: React.FC<SplitPanelLayoutConfigPanelPr
   // 🆕 좌측/우측 테이블이 모두 선택되면 엔티티 관계 자동 감지
   const [autoDetectedRelations, setAutoDetectedRelations] = useState<
     Array<{
-      leftColumn: string;
-      rightColumn: string;
+      left_column: string;
+      right_column: string;
       direction: "left_to_right" | "right_to_left";
       inputType: string;
       displayColumn?: string;
@@ -1818,8 +1818,8 @@ export const SplitPanelLayoutConfigPanel: React.FC<SplitPanelLayoutConfigPanelPr
                 useMultipleKeys: true,
                 keys: [
                   {
-                    leftColumn: firstRel.leftColumn,
-                    rightColumn: firstRel.rightColumn,
+                    leftColumn: firstRel.left_column,
+                    rightColumn: firstRel.right_column,
                   },
                 ],
               },
diff --git a/frontend/lib/registry/components/v2-split-panel-layout/config-panels/LeftPanelConfigTab.tsx b/frontend/lib/registry/components/v2-split-panel-layout/config-panels/LeftPanelConfigTab.tsx
index 7af5117d..3d548572 100644
--- a/frontend/lib/registry/components/v2-split-panel-layout/config-panels/LeftPanelConfigTab.tsx
+++ b/frontend/lib/registry/components/v2-split-panel-layout/config-panels/LeftPanelConfigTab.tsx
@@ -116,10 +116,10 @@ export const LeftPanelConfigTab: React.FC<LeftPanelConfigTabProps> = ({
                   )}
                   <CommandGroup heading="전체 테이블">
                     {allTables
-                      .filter((t) => (t.tableName || t.table_name) !== screenTableName)
+                      .filter((t) => t.table_name !== screenTableName)
                       .map((table) => {
-                        const tableName = table.tableName || table.table_name;
-                        const displayName = table.tableLabel || table.displayName || tableName;
+                        const tableName = table.table_name;
+                        const displayName = table.table_label || table.display_name || tableName;
                         return (
                           <CommandItem
                             key={tableName}
diff --git a/frontend/lib/services/dataflowJobQueue.ts b/frontend/lib/services/dataflowJobQueue.ts
index c78580ec..e76a7afe 100644
--- a/frontend/lib/services/dataflowJobQueue.ts
+++ b/frontend/lib/services/dataflowJobQueue.ts
@@ -264,8 +264,8 @@ export class DataflowJobQueue {
 
     try {
       const response = await apiClient.post("/api/button-dataflow/execute-background", {
-        buttonId: job.buttonId,
-        actionType: job.actionType,
+        button_id: job.buttonId,
+        action_type: job.actionType,
         buttonConfig: config,
         contextData,
         companyCode,
diff --git a/frontend/lib/utils/improvedButtonActionExecutor.ts b/frontend/lib/utils/improvedButtonActionExecutor.ts
index afc50235..d7a079c2 100644
--- a/frontend/lib/utils/improvedButtonActionExecutor.ts
+++ b/frontend/lib/utils/improvedButtonActionExecutor.ts
@@ -484,8 +484,8 @@ export class ImprovedButtonActionExecutor {
 
       // 백엔드 프록시 API 호출 - GenericApiSettings 형식에 맞게 전달
       const requestPayload = {
-        diagramId: relationships.diagramId || 45, // 관계 ID 사용
-        relationshipId: relationships.relationshipId || "relationship-45",
+        diagram_id: relationships.diagramId || 45, // 관계 ID 사용
+        relationship_id: relationships.relationshipId || "relationship-45",
         settings: {
           callType: "rest-api",
           apiType: "generic",
@@ -497,7 +497,7 @@ export class ImprovedButtonActionExecutor {
           timeout: restApiSettings.timeout || 30000,
           retryCount: restApiSettings.retryCount || 3,
         },
-        templateData: restApiSettings.httpMethod !== "GET" && requestBody ? JSON.parse(requestBody) : formData,
+        template_data: restApiSettings.httpMethod !== "GET" && requestBody ? JSON.parse(requestBody) : formData,
       };
 
       console.log("📤 백엔드로 전송할 데이터:", requestPayload);
@@ -706,9 +706,9 @@ export class ImprovedButtonActionExecutor {
 
       // 데이터 저장 API 호출 (apiClient 사용)
       const response = await apiClient.post("/dataflow/execute-data-action", {
-        tableName,
+        table_name: tableName,
         data,
-        actionType,
+        action_type: actionType,
         connection,
       });
 
diff --git a/frontend/lib/utils/multilang.ts b/frontend/lib/utils/multilang.ts
index 2bbb0e6b..18008dcc 100644
--- a/frontend/lib/utils/multilang.ts
+++ b/frontend/lib/utils/multilang.ts
@@ -136,13 +136,13 @@ async function fetchBatchTranslations(
     const response = await apiClient.post(
       "/multilang/batch",
       {
-        langKeys: keys,
+        lang_keys: keys,
       },
       {
         params: {
-          companyCode,
-          menuCode,
-          userLang,
+          company_code: companyCode,
+          menu_code: menuCode,
+          user_lang: userLang,
         },
       },
     );