diff --git a/web/app/components/workflow/skill/editor-tab-item.tsx b/web/app/components/workflow/skill/editor-tab-item.tsx
index d39b621cf6..b346ec2685 100644
--- a/web/app/components/workflow/skill/editor-tab-item.tsx
+++ b/web/app/components/workflow/skill/editor-tab-item.tsx
@@ -8,22 +8,7 @@ import { useCallback } from 'react'
 import { useTranslation } from 'react-i18next'
 import FileTypeIcon from '@/app/components/base/file-uploader/file-type-icon'
 import { cn } from '@/utils/classnames'
-import { getFileIconType } from './utils'
-
-/**
- * EditorTabItem - Single tab item in the tab bar
- *
- * Features:
- * - Click to activate
- * - Close button (shown on hover or when active)
- * - Dirty indicator (orange dot)
- * - File type icon based on extension
- *
- * Design specs from Figma:
- * - Height: 32px (pb-2 pt-2.5 = 18px content + padding)
- * - Font: 13px, medium (500) when active
- * - Icon: 16x16 in 20x20 container
- */
+import { getFileIconType } from './utils/file-utils'
 
 type EditorTabItemProps = {
   fileId: string
@@ -62,16 +47,13 @@ const EditorTabItem: FC<EditorTabItemProps> = ({
       )}
       onClick={handleClick}
     >
-      {/* Icon with dirty indicator */}
       <div className="relative flex size-5 shrink-0 items-center justify-center">
         <FileTypeIcon type={iconType as FileAppearanceType} size="sm" />
-        {/* Dirty indicator dot */}
         {isDirty && (
           <span className="absolute -bottom-px -right-px size-[7px] rounded-full border border-white bg-text-warning-secondary" />
         )}
       </div>
 
-      {/* File name */}
       <span
         className={cn(
           'max-w-40 truncate text-[13px] leading-4',
@@ -83,7 +65,6 @@ const EditorTabItem: FC<EditorTabItemProps> = ({
         {name}
       </span>
 
-      {/* Close button */}
       <button
         type="button"
         className={cn(
diff --git a/web/app/components/workflow/skill/editor-tabs.tsx b/web/app/components/workflow/skill/editor-tabs.tsx
index 093a5c7de8..daf7588787 100644
--- a/web/app/components/workflow/skill/editor-tabs.tsx
+++ b/web/app/components/workflow/skill/editor-tabs.tsx
@@ -1,7 +1,7 @@
 'use client'
 
 import type { FC } from 'react'
-import type { AppAssetTreeView } from './type'
+import type { AppAssetTreeView } from '@/types/app-asset'
 import * as React from 'react'
 import { useMemo } from 'react'
 import { useStore as useAppStore } from '@/app/components/app/store'
@@ -9,55 +9,34 @@ import { useGetAppAssetTree } from '@/service/use-app-asset'
 import { cn } from '@/utils/classnames'
 import EditorTabItem from './editor-tab-item'
 import { useSkillEditorStore, useSkillEditorStoreApi } from './store'
-import { buildNodeMap } from './type'
-
-/**
- * EditorTabs - Tab bar for open files
- *
- * Features:
- * - Displays open tabs from store
- * - Click to activate, close button to remove
- * - Shows dirty indicator for unsaved files
- * - Derives tab names from tree data (fileId -> file.name)
- */
+import { buildNodeMap } from './utils/tree-utils'
 
 const EditorTabs: FC = () => {
-  // Get appId
   const appDetail = useAppStore(s => s.appDetail)
   const appId = appDetail?.id || ''
 
-  // Get tree data for deriving file names
   const { data: treeData } = useGetAppAssetTree(appId)
 
-  // Store state
   const openTabIds = useSkillEditorStore(s => s.openTabIds)
   const activeTabId = useSkillEditorStore(s => s.activeTabId)
   const dirtyContents = useSkillEditorStore(s => s.dirtyContents)
   const storeApi = useSkillEditorStoreApi()
 
-  // Build node map for quick lookup
-  const treeChildren = treeData?.children
   const nodeMap = useMemo(() => {
-    if (!treeChildren)
+    if (!treeData?.children)
       return new Map<string, AppAssetTreeView>()
-    return buildNodeMap(treeChildren)
-  }, [treeChildren])
+    return buildNodeMap(treeData.children)
+  }, [treeData?.children])
 
-  // Handle tab click
   const handleTabClick = (fileId: string) => {
     storeApi.getState().activateTab(fileId)
   }
 
-  // Handle tab close
   const handleTabClose = (fileId: string) => {
-    // MVP: No dirty confirmation, just close
-    // TODO: Add confirmation dialog when file is dirty
     storeApi.getState().closeTab(fileId)
-    // Clear dirty content if exists
     storeApi.getState().clearDraftContent(fileId)
   }
 
-  // No tabs open - don't render
   if (openTabIds.length === 0)
     return null
 
diff --git a/web/app/components/workflow/skill/file-operations-menu.tsx b/web/app/components/workflow/skill/file-operations-menu.tsx
index e4ac5c6b42..1691241b16 100644
--- a/web/app/components/workflow/skill/file-operations-menu.tsx
+++ b/web/app/components/workflow/skill/file-operations-menu.tsx
@@ -12,32 +12,10 @@ import {
   RiUploadLine,
 } from '@remixicon/react'
 import * as React from 'react'
-import { useCallback, useRef, useState } from 'react'
 import { useTranslation } from 'react-i18next'
-import { useStore as useAppStore } from '@/app/components/app/store'
 import Confirm from '@/app/components/base/confirm'
-import Toast from '@/app/components/base/toast'
-import {
-  useCreateAppAssetFile,
-  useCreateAppAssetFolder,
-  useDeleteAppAssetNode,
-  useGetAppAssetTree,
-} from '@/service/use-app-asset'
 import { cn } from '@/utils/classnames'
-import { useSkillEditorStoreApi } from './store'
-import { getAllDescendantFileIds } from './type'
-
-/**
- * FileOperationsMenu - Menu content for file operations
- *
- * Shared by both context menu (right-click) and dropdown menu (... button)
- *
- * Features:
- * - New File: Create empty file (via empty Blob upload)
- * - New Folder: Create folder in target location
- * - Upload File: Upload file(s) to target folder
- * - Upload Folder: Upload entire folder structure (webkitdirectory)
- */
+import { useFileOperations } from './hooks/use-file-operations'
 
 type MenuItemProps = {
   icon: React.ElementType
@@ -64,15 +42,10 @@ const MenuItem: React.FC<MenuItemProps> = ({ icon: Icon, label, onClick, disable
 )
 
 type FileOperationsMenuProps = {
-  /** Target folder ID, or 'root' for root level */
   nodeId: string
-  /** Callback to close menu after action */
   onClose: () => void
-  /** Optional className */
   className?: string
-  /** Tree API ref for context menu (to call node.edit()) */
   treeRef?: React.RefObject<TreeApi<TreeNodeData> | null>
-  /** Node API for dropdown menu (to call node.edit()) */
   node?: NodeApi<TreeNodeData>
 }
 
@@ -84,276 +57,22 @@ const FileOperationsMenu: FC<FileOperationsMenuProps> = ({
   node,
 }) => {
   const { t } = useTranslation('workflow')
-  const fileInputRef = useRef<HTMLInputElement>(null)
-  const folderInputRef = useRef<HTMLInputElement>(null)
 
-  // Get appId from app store
-  const appDetail = useAppStore(s => s.appDetail)
-  const appId = appDetail?.id || ''
-
-  // Store API for tab cleanup
-  const storeApi = useSkillEditorStoreApi()
-
-  // Mutations
-  const createFolder = useCreateAppAssetFolder()
-  const createFile = useCreateAppAssetFile()
-  const deleteNode = useDeleteAppAssetNode()
-
-  // Tree data for descendant lookup
-  const { data: treeData } = useGetAppAssetTree(appId)
-
-  // Delete confirmation state
-  const [showDeleteConfirm, setShowDeleteConfirm] = useState(false)
-
-  // Determine parent_id (null for root)
-  const parentId = nodeId === 'root' ? null : nodeId
-
-  // Handle New File
-  const handleNewFile = useCallback(async () => {
-    // eslint-disable-next-line no-alert -- MVP: Using prompt for simplicity, will be replaced with modal later
-    const fileName = window.prompt(t('skillSidebar.menu.newFilePrompt'))
-    if (!fileName || !fileName.trim()) {
-      onClose()
-      return
-    }
-
-    try {
-      // Create empty Blob and upload as file
-      const emptyBlob = new Blob([''], { type: 'text/plain' })
-      const file = new File([emptyBlob], fileName.trim())
-
-      await createFile.mutateAsync({
-        appId,
-        name: fileName.trim(),
-        file,
-        parentId,
-      })
-
-      Toast.notify({
-        type: 'success',
-        message: t('skillSidebar.menu.fileCreated'),
-      })
-    }
-    catch {
-      Toast.notify({
-        type: 'error',
-        message: t('skillSidebar.menu.createError'),
-      })
-    }
-    finally {
-      onClose()
-    }
-  }, [appId, createFile, onClose, parentId, t])
-
-  // Handle New Folder
-  const handleNewFolder = useCallback(async () => {
-    // eslint-disable-next-line no-alert -- MVP: Using prompt for simplicity, will be replaced with modal later
-    const folderName = window.prompt(t('skillSidebar.menu.newFolderPrompt'))
-    if (!folderName || !folderName.trim()) {
-      onClose()
-      return
-    }
-
-    try {
-      await createFolder.mutateAsync({
-        appId,
-        payload: {
-          name: folderName.trim(),
-          parent_id: parentId,
-        },
-      })
-
-      Toast.notify({
-        type: 'success',
-        message: t('skillSidebar.menu.folderCreated'),
-      })
-    }
-    catch {
-      Toast.notify({
-        type: 'error',
-        message: t('skillSidebar.menu.createError'),
-      })
-    }
-    finally {
-      onClose()
-    }
-  }, [appId, createFolder, onClose, parentId, t])
-
-  // Handle file input change (single or multiple files)
-  const handleFileChange = useCallback(async (e: React.ChangeEvent<HTMLInputElement>) => {
-    const files = Array.from(e.target.files || [])
-    if (files.length === 0) {
-      onClose()
-      return
-    }
-
-    try {
-      // Upload files sequentially to avoid overwhelming the server
-      for (const file of files) {
-        await createFile.mutateAsync({
-          appId,
-          name: file.name,
-          file,
-          parentId,
-        })
-      }
-
-      Toast.notify({
-        type: 'success',
-        message: t('skillSidebar.menu.filesUploaded', { count: files.length }),
-      })
-    }
-    catch {
-      Toast.notify({
-        type: 'error',
-        message: t('skillSidebar.menu.uploadError'),
-      })
-    }
-    finally {
-      // Reset input to allow re-uploading same file
-      e.target.value = ''
-      onClose()
-    }
-  }, [appId, createFile, onClose, parentId, t])
-
-  // Handle folder input change (webkitdirectory)
-  const handleFolderChange = useCallback(async (e: React.ChangeEvent<HTMLInputElement>) => {
-    const files = Array.from(e.target.files || [])
-    if (files.length === 0) {
-      onClose()
-      return
-    }
-
-    try {
-      // Collect all unique folder paths from file paths
-      const folders = new Set<string>()
-
-      for (const file of files) {
-        const relativePath = (file as File & { webkitRelativePath?: string }).webkitRelativePath || file.name
-        const parts = relativePath.split('/')
-
-        // Collect all folder paths (parent directories)
-        if (parts.length > 1) {
-          let folderPath = ''
-          for (let i = 0; i < parts.length - 1; i++) {
-            folderPath = folderPath ? `${folderPath}/${parts[i]}` : parts[i]
-            folders.add(folderPath)
-          }
-        }
-      }
-
-      // Sort folders by depth (parent before child)
-      const sortedFolders = Array.from(folders).sort((a, b) => {
-        return a.split('/').length - b.split('/').length
-      })
-
-      // Create folders and track their IDs
-      const folderIdMap = new Map<string, string | null>()
-      folderIdMap.set('', parentId) // Root maps to target parent
-
-      for (const folderPath of sortedFolders) {
-        const parts = folderPath.split('/')
-        const folderName = parts[parts.length - 1]
-        const parentPath = parts.slice(0, -1).join('/')
-        const parentFolderId = folderIdMap.get(parentPath) ?? parentId
-
-        const result = await createFolder.mutateAsync({
-          appId,
-          payload: {
-            name: folderName,
-            parent_id: parentFolderId,
-          },
-        })
-
-        folderIdMap.set(folderPath, result.id)
-      }
-
-      // Upload files to their respective folders
-      for (const file of files) {
-        const relativePath = (file as File & { webkitRelativePath?: string }).webkitRelativePath || file.name
-        const parts = relativePath.split('/')
-        const parentPath = parts.length > 1 ? parts.slice(0, -1).join('/') : ''
-        const targetParentId = folderIdMap.get(parentPath) ?? parentId
-
-        await createFile.mutateAsync({
-          appId,
-          name: file.name,
-          file,
-          parentId: targetParentId,
-        })
-      }
-
-      Toast.notify({
-        type: 'success',
-        message: t('skillSidebar.menu.folderUploaded'),
-      })
-    }
-    catch {
-      Toast.notify({
-        type: 'error',
-        message: t('skillSidebar.menu.uploadError'),
-      })
-    }
-    finally {
-      // Reset input
-      e.target.value = ''
-      onClose()
-    }
-  }, [appId, createFile, createFolder, onClose, parentId, t])
-
-  // Handle Rename - trigger react-arborist inline editing
-  const handleRename = useCallback(() => {
-    // Context menu: use treeRef
-    if (treeRef?.current) {
-      const targetNode = treeRef.current.get(nodeId)
-      targetNode?.edit()
-    }
-    // Dropdown: use node directly
-    else if (node) {
-      node.edit()
-    }
-    onClose()
-  }, [nodeId, node, onClose, treeRef])
-
-  // Handle Delete click - show confirmation
-  const handleDeleteClick = useCallback(() => {
-    setShowDeleteConfirm(true)
-  }, [])
-
-  // Handle Delete confirm
-  const handleDeleteConfirm = useCallback(async () => {
-    try {
-      // Find descendant file IDs for tab cleanup
-      const descendantFileIds = treeData?.children
-        ? getAllDescendantFileIds(nodeId, treeData.children)
-        : []
-
-      await deleteNode.mutateAsync({ appId, nodeId })
-
-      // Close tabs for deleted files
-      descendantFileIds.forEach((fileId) => {
-        storeApi.getState().closeTab(fileId)
-        storeApi.getState().clearDraftContent(fileId)
-      })
-
-      Toast.notify({
-        type: 'success',
-        message: t('skillSidebar.menu.deleted'),
-      })
-    }
-    catch {
-      Toast.notify({
-        type: 'error',
-        message: t('skillSidebar.menu.deleteError'),
-      })
-    }
-    finally {
-      setShowDeleteConfirm(false)
-      onClose()
-    }
-  }, [appId, nodeId, deleteNode, storeApi, treeData?.children, onClose, t])
-
-  const isLoading = createFile.isPending || createFolder.isPending || deleteNode.isPending
+  const {
+    fileInputRef,
+    folderInputRef,
+    showDeleteConfirm,
+    isLoading,
+    isDeleting,
+    handleNewFile,
+    handleNewFolder,
+    handleFileChange,
+    handleFolderChange,
+    handleRename,
+    handleDeleteClick,
+    handleDeleteConfirm,
+    handleDeleteCancel,
+  } = useFileOperations({ nodeId, onClose, treeRef, node })
 
   return (
     <div className={cn(
@@ -362,7 +81,6 @@ const FileOperationsMenu: FC<FileOperationsMenuProps> = ({
       className,
     )}
     >
-      {/* Hidden file inputs */}
       <input
         ref={fileInputRef}
         type="file"
@@ -392,7 +110,6 @@ const FileOperationsMenu: FC<FileOperationsMenuProps> = ({
         disabled={isLoading}
       />
 
-      {/* Divider */}
       <div className="my-1 h-px bg-divider-subtle" />
 
       <MenuItem
@@ -408,7 +125,6 @@ const FileOperationsMenu: FC<FileOperationsMenuProps> = ({
         disabled={isLoading}
       />
 
-      {/* Divider before destructive actions */}
       {nodeId !== 'root' && (
         <>
           <div className="my-1 h-px bg-divider-subtle" />
@@ -437,15 +153,14 @@ const FileOperationsMenu: FC<FileOperationsMenuProps> = ({
         </>
       )}
 
-      {/* Delete confirmation modal */}
       <Confirm
         isShow={showDeleteConfirm}
         type="danger"
         title={t('skillSidebar.menu.deleteConfirmTitle')}
         content={t('skillSidebar.menu.deleteConfirmContent')}
         onConfirm={handleDeleteConfirm}
-        onCancel={() => setShowDeleteConfirm(false)}
-        isLoading={deleteNode.isPending}
+        onCancel={handleDeleteCancel}
+        isLoading={isDeleting}
       />
     </div>
   )
diff --git a/web/app/components/workflow/skill/file-tree-context-menu.tsx b/web/app/components/workflow/skill/file-tree-context-menu.tsx
index 971218f2be..9b8c48a8e7 100644
--- a/web/app/components/workflow/skill/file-tree-context-menu.tsx
+++ b/web/app/components/workflow/skill/file-tree-context-menu.tsx
@@ -13,12 +13,6 @@ type FileTreeContextMenuProps = {
   treeRef: React.RefObject<TreeApi<TreeNodeData> | null>
 }
 
-/**
- * FileTreeContextMenu - Right-click context menu for file tree
- *
- * Renders at absolute position when contextMenu state is set.
- * Uses useClickAway to close when clicking outside.
- */
 const FileTreeContextMenu: FC<FileTreeContextMenuProps> = ({ treeRef }) => {
   const ref = useRef<HTMLDivElement>(null)
   const contextMenu = useSkillEditorStore(s => s.contextMenu)
diff --git a/web/app/components/workflow/skill/file-tree-node.tsx b/web/app/components/workflow/skill/file-tree-node.tsx
index 35f0941168..3e71f9811c 100644
--- a/web/app/components/workflow/skill/file-tree-node.tsx
+++ b/web/app/components/workflow/skill/file-tree-node.tsx
@@ -15,33 +15,16 @@ import {
 import { cn } from '@/utils/classnames'
 import FileOperationsMenu from './file-operations-menu'
 import { useSkillEditorStore, useSkillEditorStoreApi } from './store'
-import { getFileIconType } from './utils'
+import { getFileIconType } from './utils/file-utils'
 
-/**
- * FileTreeNode - Custom node renderer for react-arborist
- *
- * Matches Figma design specifications:
- * - Row height: 24px
- * - Icon size: 16x16 in 20x20 container
- * - Font: 13px Inter, regular (400) / medium (500) for selected
- * - Colors: text-secondary (#354052), text-primary (#101828) for selected
- * - Hover bg: rgba(200,206,218,0.2), Active bg: rgba(200,206,218,0.4)
- * - Folder icon: blue (#155aef) when open
- *
- * Features:
- * - Right-click context menu for folders
- * - "..." button dropdown for folders (visible on hover)
- */
 const FileTreeNode = ({ node, style, dragHandle }: NodeRendererProps<TreeNodeData>) => {
   const isFolder = node.data.node_type === 'folder'
   const isSelected = node.isSelected
   const isDirty = useSkillEditorStore(s => s.dirtyContents.has(node.data.id))
   const storeApi = useSkillEditorStoreApi()
 
-  // Dropdown menu state (for ... button)
   const [showDropdown, setShowDropdown] = useState(false)
 
-  // Get file icon type for files
   const fileIconType = !isFolder ? getFileIconType(node.data.name) : null
 
   const handleClick = (e: React.MouseEvent) => {
@@ -51,7 +34,6 @@ const FileTreeNode = ({ node, style, dragHandle }: NodeRendererProps<TreeNodeDat
 
   const handleDoubleClick = (e: React.MouseEvent) => {
     e.stopPropagation()
-    // For files, activate (open in editor)
     if (!isFolder)
       node.activate()
   }
@@ -61,9 +43,7 @@ const FileTreeNode = ({ node, style, dragHandle }: NodeRendererProps<TreeNodeDat
     node.toggle()
   }
 
-  // Right-click context menu handler (folders only)
   const handleContextMenu = useCallback((e: React.MouseEvent) => {
-    // Only show context menu for folders
     if (!isFolder)
       return
 
@@ -77,7 +57,6 @@ const FileTreeNode = ({ node, style, dragHandle }: NodeRendererProps<TreeNodeDat
     })
   }, [isFolder, node.data.id, storeApi])
 
-  // More button click handler
   const handleMoreClick = useCallback((e: React.MouseEvent) => {
     e.stopPropagation()
     setShowDropdown(prev => !prev)
@@ -96,7 +75,6 @@ const FileTreeNode = ({ node, style, dragHandle }: NodeRendererProps<TreeNodeDat
       onDoubleClick={handleDoubleClick}
       onContextMenu={handleContextMenu}
     >
-      {/* Icon */}
       <div className="flex size-5 shrink-0 items-center justify-center">
         {isFolder
           ? (
@@ -113,7 +91,6 @@ const FileTreeNode = ({ node, style, dragHandle }: NodeRendererProps<TreeNodeDat
           : (
               <div className="relative flex size-full items-center justify-center">
                 <FileTypeIcon type={fileIconType as FileAppearanceType} size="sm" />
-                {/* Dirty indicator dot */}
                 {isDirty && (
                   <span className="absolute -bottom-px -right-px size-[7px] rounded-full border border-white bg-text-warning-secondary" />
                 )}
@@ -121,7 +98,6 @@ const FileTreeNode = ({ node, style, dragHandle }: NodeRendererProps<TreeNodeDat
             )}
       </div>
 
-      {/* Name */}
       <span
         className={cn(
           'min-w-0 flex-1 truncate text-[13px] leading-4',
@@ -133,7 +109,6 @@ const FileTreeNode = ({ node, style, dragHandle }: NodeRendererProps<TreeNodeDat
         {node.data.name}
       </span>
 
-      {/* More button - only for folders, visible on hover */}
       {isFolder && (
         <PortalToFollowElem
           placement="bottom-start"
diff --git a/web/app/components/workflow/skill/files.tsx b/web/app/components/workflow/skill/files.tsx
index bbdfbcee28..85504d6a68 100644
--- a/web/app/components/workflow/skill/files.tsx
+++ b/web/app/components/workflow/skill/files.tsx
@@ -15,22 +15,7 @@ import { cn } from '@/utils/classnames'
 import FileTreeContextMenu from './file-tree-context-menu'
 import FileTreeNode from './file-tree-node'
 import { useSkillEditorStore, useSkillEditorStoreApi } from './store'
-import { getAncestorIds, toOpensObject } from './type'
-
-/**
- * Files - File tree component using react-arborist
- *
- * Key features:
- * - Controlled open state via TreeApi (synced with SkillEditorStore)
- * - Click to select, double-click to open in tab
- * - Auto-expand when tab is activated
- * - Virtual scrolling for large trees
- *
- * Design specs from Figma:
- * - Row height: 24px
- * - Indent: 20px
- * - Container padding: 4px
- */
+import { getAncestorIds, toOpensObject } from './utils/tree-utils'
 
 type FilesProps = {
   className?: string
@@ -52,42 +37,30 @@ const Files: React.FC<FilesProps> = ({ className }) => {
   const { t } = useTranslation('workflow')
   const treeRef = useRef<TreeApi<TreeNodeData>>(null)
 
-  // Get appId from app store
   const appDetail = useAppStore(s => s.appDetail)
   const appId = appDetail?.id || ''
 
-  // Fetch tree data from API
   const { data: treeData, isLoading, error } = useGetAppAssetTree(appId)
 
-  // Store state and actions
   const expandedFolderIds = useSkillEditorStore(s => s.expandedFolderIds)
   const activeTabId = useSkillEditorStore(s => s.activeTabId)
   const storeApi = useSkillEditorStoreApi()
 
-  // Rename mutation for inline editing
   const renameNode = useRenameAppAssetNode()
 
-  // Convert Set to react-arborist OpenMap for initial state
   const initialOpenState = useMemo(() => toOpensObject(expandedFolderIds), [expandedFolderIds])
 
-  // Handle toggle event from react-arborist
   const handleToggle = useCallback((id: string) => {
     storeApi.getState().toggleFolder(id)
   }, [storeApi])
 
-  // Handle node activation (double-click or Enter)
   const handleActivate = useCallback((node: NodeApi<TreeNodeData>) => {
-    if (node.data.node_type === 'file') {
-      // Open file in tab
+    if (node.data.node_type === 'file')
       storeApi.getState().openTab(node.data.id)
-    }
-    else {
-      // For folders, toggle open state
+    else
       node.toggle()
-    }
   }, [storeApi])
 
-  // Handle rename from react-arborist inline editing
   const handleRename = useCallback(({ id, name }: { id: string, name: string }) => {
     renameNode.mutateAsync({
       appId,
@@ -101,31 +74,26 @@ const Files: React.FC<FilesProps> = ({ className }) => {
     })
   }, [appId, renameNode, t])
 
-  // Auto-reveal when activeTabId changes (sync from tab click to tree)
   useEffect(() => {
     if (!activeTabId || !treeData?.children || !treeRef.current)
       return
 
     const ancestors = getAncestorIds(activeTabId, treeData.children)
 
-    // Update store for state persistence
     if (ancestors.length > 0)
       storeApi.getState().revealFile(ancestors)
 
-    // Use Tree API for immediate UI update (initialOpenState only applies on first render)
     const timeoutId = setTimeout(() => {
       const tree = treeRef.current
       if (!tree)
         return
 
-      // Open all ancestor folders
       for (const ancestorId of ancestors) {
         const ancestorNode = tree.get(ancestorId)
         if (ancestorNode && !ancestorNode.isOpen)
           ancestorNode.open()
       }
 
-      // Select the target node
       const node = tree.get(activeTabId)
       if (node)
         node.select()
@@ -134,7 +102,6 @@ const Files: React.FC<FilesProps> = ({ className }) => {
     return () => clearTimeout(timeoutId)
   }, [activeTabId, treeData?.children, storeApi])
 
-  // Loading state
   if (isLoading) {
     return (
       <div className={cn('flex min-h-0 flex-1 items-center justify-center', className)}>
@@ -143,7 +110,6 @@ const Files: React.FC<FilesProps> = ({ className }) => {
     )
   }
 
-  // Error state
   if (error) {
     return (
       <div className={cn('flex min-h-0 flex-1 flex-col items-center justify-center gap-2 text-text-tertiary', className)}>
@@ -154,7 +120,6 @@ const Files: React.FC<FilesProps> = ({ className }) => {
     )
   }
 
-  // Empty state
   if (!treeData?.children || treeData.children.length === 0) {
     return (
       <div className={cn('flex min-h-0 flex-1 flex-col', className)}>
@@ -174,24 +139,18 @@ const Files: React.FC<FilesProps> = ({ className }) => {
         <Tree<TreeNodeData>
           ref={treeRef}
           data={treeData.children}
-          // Structure accessors
           idAccessor="id"
           childrenAccessor="children"
-          // Layout
           width="100%"
           height={1000}
           rowHeight={24}
           indent={20}
           overscanCount={5}
-          // Initial open state
           initialOpenState={initialOpenState}
-          // Selection (controlled by activeTabId)
           selection={activeTabId ?? undefined}
-          // Events
           onToggle={handleToggle}
           onActivate={handleActivate}
           onRename={handleRename}
-          // Disable features not in MVP
           disableDrag
           disableDrop
         >
@@ -199,7 +158,6 @@ const Files: React.FC<FilesProps> = ({ className }) => {
         </Tree>
       </div>
       <DropTip />
-      {/* Right-click context menu */}
       <FileTreeContextMenu treeRef={treeRef} />
     </div>
   )
diff --git a/web/app/components/workflow/skill/hooks/use-file-operations.ts b/web/app/components/workflow/skill/hooks/use-file-operations.ts
new file mode 100644
index 0000000000..5621f165c1
--- /dev/null
+++ b/web/app/components/workflow/skill/hooks/use-file-operations.ts
@@ -0,0 +1,293 @@
+'use client'
+
+import type { NodeApi, TreeApi } from 'react-arborist'
+import type { TreeNodeData } from '../type'
+import { useCallback, useRef, useState } from 'react'
+import { useTranslation } from 'react-i18next'
+import { useStore as useAppStore } from '@/app/components/app/store'
+import Toast from '@/app/components/base/toast'
+import {
+  useCreateAppAssetFile,
+  useCreateAppAssetFolder,
+  useDeleteAppAssetNode,
+  useGetAppAssetTree,
+} from '@/service/use-app-asset'
+import { useSkillEditorStoreApi } from '../store'
+import { getAllDescendantFileIds } from '../utils/tree-utils'
+
+type UseFileOperationsOptions = {
+  nodeId: string
+  onClose: () => void
+  treeRef?: React.RefObject<TreeApi<TreeNodeData> | null>
+  node?: NodeApi<TreeNodeData>
+}
+
+export function useFileOperations({
+  nodeId,
+  onClose,
+  treeRef,
+  node,
+}: UseFileOperationsOptions) {
+  const { t } = useTranslation('workflow')
+  const fileInputRef = useRef<HTMLInputElement>(null)
+  const folderInputRef = useRef<HTMLInputElement>(null)
+  const [showDeleteConfirm, setShowDeleteConfirm] = useState(false)
+
+  const appDetail = useAppStore(s => s.appDetail)
+  const appId = appDetail?.id || ''
+  const storeApi = useSkillEditorStoreApi()
+
+  const createFolder = useCreateAppAssetFolder()
+  const createFile = useCreateAppAssetFile()
+  const deleteNode = useDeleteAppAssetNode()
+  const { data: treeData } = useGetAppAssetTree(appId)
+
+  const parentId = nodeId === 'root' ? null : nodeId
+
+  const handleNewFile = useCallback(async () => {
+    // eslint-disable-next-line no-alert -- MVP: Using prompt for simplicity
+    const fileName = window.prompt(t('skillSidebar.menu.newFilePrompt'))
+    if (!fileName || !fileName.trim()) {
+      onClose()
+      return
+    }
+
+    try {
+      const emptyBlob = new Blob([''], { type: 'text/plain' })
+      const file = new File([emptyBlob], fileName.trim())
+
+      await createFile.mutateAsync({
+        appId,
+        name: fileName.trim(),
+        file,
+        parentId,
+      })
+
+      Toast.notify({
+        type: 'success',
+        message: t('skillSidebar.menu.fileCreated'),
+      })
+    }
+    catch {
+      Toast.notify({
+        type: 'error',
+        message: t('skillSidebar.menu.createError'),
+      })
+    }
+    finally {
+      onClose()
+    }
+  }, [appId, createFile, onClose, parentId, t])
+
+  const handleNewFolder = useCallback(async () => {
+    // eslint-disable-next-line no-alert -- MVP: Using prompt for simplicity
+    const folderName = window.prompt(t('skillSidebar.menu.newFolderPrompt'))
+    if (!folderName || !folderName.trim()) {
+      onClose()
+      return
+    }
+
+    try {
+      await createFolder.mutateAsync({
+        appId,
+        payload: {
+          name: folderName.trim(),
+          parent_id: parentId,
+        },
+      })
+
+      Toast.notify({
+        type: 'success',
+        message: t('skillSidebar.menu.folderCreated'),
+      })
+    }
+    catch {
+      Toast.notify({
+        type: 'error',
+        message: t('skillSidebar.menu.createError'),
+      })
+    }
+    finally {
+      onClose()
+    }
+  }, [appId, createFolder, onClose, parentId, t])
+
+  const handleFileChange = useCallback(async (e: React.ChangeEvent<HTMLInputElement>) => {
+    const files = Array.from(e.target.files || [])
+    if (files.length === 0) {
+      onClose()
+      return
+    }
+
+    try {
+      for (const file of files) {
+        await createFile.mutateAsync({
+          appId,
+          name: file.name,
+          file,
+          parentId,
+        })
+      }
+
+      Toast.notify({
+        type: 'success',
+        message: t('skillSidebar.menu.filesUploaded', { count: files.length }),
+      })
+    }
+    catch {
+      Toast.notify({
+        type: 'error',
+        message: t('skillSidebar.menu.uploadError'),
+      })
+    }
+    finally {
+      e.target.value = ''
+      onClose()
+    }
+  }, [appId, createFile, onClose, parentId, t])
+
+  const handleFolderChange = useCallback(async (e: React.ChangeEvent<HTMLInputElement>) => {
+    const files = Array.from(e.target.files || [])
+    if (files.length === 0) {
+      onClose()
+      return
+    }
+
+    try {
+      const folders = new Set<string>()
+
+      for (const file of files) {
+        const relativePath = (file as File & { webkitRelativePath?: string }).webkitRelativePath || file.name
+        const parts = relativePath.split('/')
+
+        if (parts.length > 1) {
+          let folderPath = ''
+          for (let i = 0; i < parts.length - 1; i++) {
+            folderPath = folderPath ? `${folderPath}/${parts[i]}` : parts[i]
+            folders.add(folderPath)
+          }
+        }
+      }
+
+      const sortedFolders = Array.from(folders).sort((a, b) => {
+        return a.split('/').length - b.split('/').length
+      })
+
+      const folderIdMap = new Map<string, string | null>()
+      folderIdMap.set('', parentId)
+
+      for (const folderPath of sortedFolders) {
+        const parts = folderPath.split('/')
+        const folderName = parts[parts.length - 1]
+        const parentPath = parts.slice(0, -1).join('/')
+        const parentFolderId = folderIdMap.get(parentPath) ?? parentId
+
+        const result = await createFolder.mutateAsync({
+          appId,
+          payload: {
+            name: folderName,
+            parent_id: parentFolderId,
+          },
+        })
+
+        folderIdMap.set(folderPath, result.id)
+      }
+
+      for (const file of files) {
+        const relativePath = (file as File & { webkitRelativePath?: string }).webkitRelativePath || file.name
+        const parts = relativePath.split('/')
+        const parentPath = parts.length > 1 ? parts.slice(0, -1).join('/') : ''
+        const targetParentId = folderIdMap.get(parentPath) ?? parentId
+
+        await createFile.mutateAsync({
+          appId,
+          name: file.name,
+          file,
+          parentId: targetParentId,
+        })
+      }
+
+      Toast.notify({
+        type: 'success',
+        message: t('skillSidebar.menu.folderUploaded'),
+      })
+    }
+    catch {
+      Toast.notify({
+        type: 'error',
+        message: t('skillSidebar.menu.uploadError'),
+      })
+    }
+    finally {
+      e.target.value = ''
+      onClose()
+    }
+  }, [appId, createFile, createFolder, onClose, parentId, t])
+
+  const handleRename = useCallback(() => {
+    if (treeRef?.current) {
+      const targetNode = treeRef.current.get(nodeId)
+      targetNode?.edit()
+    }
+    else if (node) {
+      node.edit()
+    }
+    onClose()
+  }, [nodeId, node, onClose, treeRef])
+
+  const handleDeleteClick = useCallback(() => {
+    setShowDeleteConfirm(true)
+  }, [])
+
+  const handleDeleteConfirm = useCallback(async () => {
+    try {
+      const descendantFileIds = treeData?.children
+        ? getAllDescendantFileIds(nodeId, treeData.children)
+        : []
+
+      await deleteNode.mutateAsync({ appId, nodeId })
+
+      descendantFileIds.forEach((fileId) => {
+        storeApi.getState().closeTab(fileId)
+        storeApi.getState().clearDraftContent(fileId)
+      })
+
+      Toast.notify({
+        type: 'success',
+        message: t('skillSidebar.menu.deleted'),
+      })
+    }
+    catch {
+      Toast.notify({
+        type: 'error',
+        message: t('skillSidebar.menu.deleteError'),
+      })
+    }
+    finally {
+      setShowDeleteConfirm(false)
+      onClose()
+    }
+  }, [appId, nodeId, deleteNode, storeApi, treeData?.children, onClose, t])
+
+  const handleDeleteCancel = useCallback(() => {
+    setShowDeleteConfirm(false)
+  }, [])
+
+  const isLoading = createFile.isPending || createFolder.isPending || deleteNode.isPending
+
+  return {
+    fileInputRef,
+    folderInputRef,
+    showDeleteConfirm,
+    isLoading,
+    isDeleting: deleteNode.isPending,
+    handleNewFile,
+    handleNewFolder,
+    handleFileChange,
+    handleFolderChange,
+    handleRename,
+    handleDeleteClick,
+    handleDeleteConfirm,
+    handleDeleteCancel,
+  }
+}
diff --git a/web/app/components/workflow/skill/sidebar-search-add.tsx b/web/app/components/workflow/skill/sidebar-search-add.tsx
index 9e851bdf03..8559850671 100644
--- a/web/app/components/workflow/skill/sidebar-search-add.tsx
+++ b/web/app/components/workflow/skill/sidebar-search-add.tsx
@@ -13,37 +13,23 @@ import Toast from '@/app/components/base/toast'
 import { useCreateAppAssetFile, useCreateAppAssetFolder } from '@/service/use-app-asset'
 import { cn } from '@/utils/classnames'
 
-/**
- * SidebarSearchAdd - Search input and add button for file operations
- *
- * Features:
- * - Search input for filtering files (TODO: implement filter logic)
- * - Add button with dropdown menu:
- *   - New folder: creates a folder at root level
- *   - Upload file: opens file picker to upload
- */
 const SidebarSearchAdd: FC = () => {
   const { t } = useTranslation('workflow')
   const [searchValue, setSearchValue] = useState('')
   const [showMenu, setShowMenu] = useState(false)
   const fileInputRef = useRef<HTMLInputElement>(null)
 
-  // Get appId from app store
   const appDetail = useAppStore(s => s.appDetail)
   const appId = appDetail?.id || ''
 
-  // Mutations
   const createFolder = useCreateAppAssetFolder()
   const createFile = useCreateAppAssetFile()
 
-  // Handle new folder
   const handleNewFolder = useCallback(async () => {
     setShowMenu(false)
     if (!appId)
       return
 
-    // For MVP, create folder with default name at root level
-    // TODO: Add inline rename UI after creation
     const timestamp = Date.now()
     const folderName = `${t('skillSidebar.newFolder')}-${timestamp}`
 
@@ -52,7 +38,7 @@ const SidebarSearchAdd: FC = () => {
         appId,
         payload: {
           name: folderName,
-          parent_id: null, // Root level
+          parent_id: null,
         },
       })
       Toast.notify({
@@ -68,13 +54,11 @@ const SidebarSearchAdd: FC = () => {
     }
   }, [appId, createFolder, t])
 
-  // Handle upload file click
   const handleUploadClick = useCallback(() => {
     setShowMenu(false)
     fileInputRef.current?.click()
   }, [])
 
-  // Handle file selection
   const handleFileChange = useCallback(async (e: React.ChangeEvent<HTMLInputElement>) => {
     const files = e.target.files
     if (!files || files.length === 0 || !appId)
@@ -87,7 +71,7 @@ const SidebarSearchAdd: FC = () => {
         appId,
         name: file.name,
         file,
-        parentId: null, // Root level
+        parentId: null,
       })
       Toast.notify({
         type: 'success',
@@ -101,7 +85,6 @@ const SidebarSearchAdd: FC = () => {
       })
     }
 
-    // Reset input to allow re-uploading same file
     e.target.value = ''
   }, [appId, createFile, t])
 
@@ -131,7 +114,6 @@ const SidebarSearchAdd: FC = () => {
         </PortalToFollowElemTrigger>
         <PortalToFollowElemContent className="z-[30]">
           <div className="flex min-w-[160px] flex-col rounded-xl border-[0.5px] border-components-panel-border bg-components-panel-bg-blur p-1 shadow-lg backdrop-blur-[5px]">
-            {/* New Folder */}
             <div
               className="flex h-8 cursor-pointer items-center gap-2 rounded-lg px-2 hover:bg-state-base-hover"
               onClick={handleNewFolder}
@@ -141,7 +123,6 @@ const SidebarSearchAdd: FC = () => {
                 {t('skillSidebar.addFolder')}
               </span>
             </div>
-            {/* Upload File */}
             <div
               className="flex h-8 cursor-pointer items-center gap-2 rounded-lg px-2 hover:bg-state-base-hover"
               onClick={handleUploadClick}
@@ -155,7 +136,6 @@ const SidebarSearchAdd: FC = () => {
         </PortalToFollowElemContent>
       </PortalToFollowElem>
 
-      {/* Hidden file input */}
       <input
         ref={fileInputRef}
         type="file"
diff --git a/web/app/components/workflow/skill/skill-doc-editor.tsx b/web/app/components/workflow/skill/skill-doc-editor.tsx
index 58e41f10ca..b6eb1465d0 100644
--- a/web/app/components/workflow/skill/skill-doc-editor.tsx
+++ b/web/app/components/workflow/skill/skill-doc-editor.tsx
@@ -2,7 +2,7 @@
 
 import type { OnMount } from '@monaco-editor/react'
 import type { FC } from 'react'
-import type { AppAssetTreeView } from './type'
+import type { AppAssetTreeView } from '@/types/app-asset'
 import { loader } from '@monaco-editor/react'
 import * as React from 'react'
 import { useCallback, useEffect, useMemo, useRef, useState } from 'react'
@@ -20,103 +20,72 @@ import MediaFilePreview from './editor/media-file-preview'
 import OfficeFilePlaceholder from './editor/office-file-placeholder'
 import UnsupportedFileDownload from './editor/unsupported-file-download'
 import { useSkillEditorStore, useSkillEditorStoreApi } from './store'
-import { buildNodeMap } from './type'
-import { getFileExtension, getFileLanguage, isCodeOrTextFile, isImageFile, isMarkdownFile, isOfficeFile, isVideoFile } from './utils'
+import { getFileExtension, getFileLanguage, isCodeOrTextFile, isImageFile, isMarkdownFile, isOfficeFile, isVideoFile } from './utils/file-utils'
+import { buildNodeMap } from './utils/tree-utils'
 
-// load file from local instead of cdn
 if (typeof window !== 'undefined')
   loader.config({ paths: { vs: `${window.location.origin}${basePath}/vs` } })
 
-/**
- * SkillDocEditor - Document editor for skill files
- *
- * Features:
- * - Monaco editor for code/text editing
- * - Auto-load content when tab is activated
- * - Dirty state tracking via store
- * - Save with Ctrl+S / Cmd+S
- *
- * Design notes from MVP:
- * - `dirtyContents` only stores modified content, not full cache
- * - `dirty = dirtyContents.has(fileId)`, no diff with server content
- * - closeTab doesn't show dirty confirmation dialog (MVP)
- */
 const SkillDocEditor: FC = () => {
   const { t } = useTranslation('workflow')
   const { theme: appTheme } = useTheme()
   const [isMounted, setIsMounted] = useState(false)
   const editorRef = useRef<Parameters<OnMount>[0] | null>(null)
 
-  // Get appId from app store
   const appDetail = useAppStore(s => s.appDetail)
   const appId = appDetail?.id || ''
 
-  // Store state
   const activeTabId = useSkillEditorStore(s => s.activeTabId)
   const dirtyContents = useSkillEditorStore(s => s.dirtyContents)
   const storeApi = useSkillEditorStoreApi()
 
-  // Fetch tree data for file name lookup
   const { data: treeData } = useGetAppAssetTree(appId)
 
-  // Build node map for quick lookup
-  const treeChildren = treeData?.children
   const nodeMap = useMemo(() => {
-    if (!treeChildren)
+    if (!treeData?.children)
       return new Map<string, AppAssetTreeView>()
-    return buildNodeMap(treeChildren)
-  }, [treeChildren])
+    return buildNodeMap(treeData.children)
+  }, [treeData?.children])
 
-  // Get current file node
   const currentFileNode = activeTabId ? nodeMap.get(activeTabId) : undefined
-  const fileExtension = useMemo(() => {
-    return getFileExtension(currentFileNode?.name, currentFileNode?.extension)
-  }, [currentFileNode?.extension, currentFileNode?.name])
-  const isMarkdown = useMemo(() => isMarkdownFile(fileExtension), [fileExtension])
-  const isCodeOrText = useMemo(() => isCodeOrTextFile(fileExtension), [fileExtension])
-  const isImage = useMemo(() => isImageFile(fileExtension), [fileExtension])
-  const isVideo = useMemo(() => isVideoFile(fileExtension), [fileExtension])
-  const isOffice = useMemo(() => isOfficeFile(fileExtension), [fileExtension])
+  const fileExtension = getFileExtension(currentFileNode?.name, currentFileNode?.extension)
+  const isMarkdown = isMarkdownFile(fileExtension)
+  const isCodeOrText = isCodeOrTextFile(fileExtension)
+  const isImage = isImageFile(fileExtension)
+  const isVideo = isVideoFile(fileExtension)
+  const isOffice = isOfficeFile(fileExtension)
   const isEditable = isMarkdown || isCodeOrText
 
-  // Fetch file content from API
   const {
     data: fileContent,
     isLoading,
     error,
   } = useGetAppAssetFileContent(appId, activeTabId || '')
 
-  // Save mutation
   const updateContent = useUpdateAppAssetFileContent()
 
-  // Get draft content or server content
   const currentContent = useMemo(() => {
     if (!activeTabId)
       return ''
-    // Check if there's a draft first
     const draft = dirtyContents.get(activeTabId)
     if (draft !== undefined)
       return draft
-    // Otherwise use server content
     return fileContent?.content ?? ''
   }, [activeTabId, dirtyContents, fileContent?.content])
 
-  // Handle editor content change
   const handleEditorChange = useCallback((value: string | undefined) => {
     if (!activeTabId || !isEditable)
       return
-    // Set draft content in store
     storeApi.getState().setDraftContent(activeTabId, value ?? '')
   }, [activeTabId, isEditable, storeApi])
 
-  // Handle save
   const handleSave = useCallback(async () => {
     if (!activeTabId || !appId || !isEditable)
       return
 
     const content = dirtyContents.get(activeTabId)
     if (content === undefined)
-      return // No changes to save
+      return
 
     try {
       await updateContent.mutateAsync({
@@ -124,7 +93,6 @@ const SkillDocEditor: FC = () => {
         nodeId: activeTabId,
         payload: { content },
       })
-      // Clear draft on success
       storeApi.getState().clearDraftContent(activeTabId)
       Toast.notify({
         type: 'success',
@@ -139,10 +107,8 @@ const SkillDocEditor: FC = () => {
     }
   }, [activeTabId, appId, dirtyContents, isEditable, storeApi, t, updateContent])
 
-  // Handle keyboard shortcuts
   useEffect(() => {
-    const handleKeyDown = (e: KeyboardEvent) => {
-      // Ctrl+S / Cmd+S to save
+    function handleKeyDown(e: KeyboardEvent): void {
       if ((e.ctrlKey || e.metaKey) && e.key === 's') {
         e.preventDefault()
         handleSave()
@@ -153,26 +119,15 @@ const SkillDocEditor: FC = () => {
     return () => window.removeEventListener('keydown', handleKeyDown)
   }, [handleSave])
 
-  // Handle editor mount
   const handleEditorDidMount: OnMount = useCallback((editor, monaco) => {
     editorRef.current = editor
     monaco.editor.setTheme(appTheme === Theme.light ? 'light' : 'vs-dark')
     setIsMounted(true)
   }, [appTheme])
 
-  // Determine editor language from file extension
-  const language = useMemo(() => {
-    if (!activeTabId || !currentFileNode)
-      return 'plaintext'
-    // Get language from file name in tree data
-    return getFileLanguage(currentFileNode.name)
-  }, [activeTabId, currentFileNode])
+  const language = currentFileNode ? getFileLanguage(currentFileNode.name) : 'plaintext'
+  const theme = appTheme === Theme.light ? 'light' : 'vs-dark'
 
-  const theme = useMemo(() => {
-    return appTheme === Theme.light ? 'light' : 'vs-dark'
-  }, [appTheme])
-
-  // No active tab
   if (!activeTabId) {
     return (
       <div className="flex h-full w-full items-center justify-center bg-components-panel-bg text-text-tertiary">
@@ -183,7 +138,6 @@ const SkillDocEditor: FC = () => {
     )
   }
 
-  // Loading state
   if (isLoading) {
     return (
       <div className="flex h-full w-full items-center justify-center bg-components-panel-bg">
@@ -192,7 +146,6 @@ const SkillDocEditor: FC = () => {
     )
   }
 
-  // Error state
   if (error) {
     return (
       <div className="flex h-full w-full items-center justify-center bg-components-panel-bg text-text-tertiary">
diff --git a/web/app/components/workflow/skill/store/index.ts b/web/app/components/workflow/skill/store/index.ts
index a69f4a9016..8daea51961 100644
--- a/web/app/components/workflow/skill/store/index.ts
+++ b/web/app/components/workflow/skill/store/index.ts
@@ -4,41 +4,21 @@ import { useContext } from 'react'
 import { useStore as useZustandStore } from 'zustand'
 import { createStore } from 'zustand/vanilla'
 
-/**
- * SkillEditorStore - Zustand Store for Skill Editor
- *
- * Based on MVP Design Document (docs/design/skill-editor-file-list-tab-mvp-design.md)
- *
- * Key principles:
- * - Server data via TanStack Query (useGetAppAssetTree, etc.)
- * - Client store only for UI state (tabs, expanded folders, dirty contents)
- * - Store uses fileId only, tab display name derived from tree data
- */
-
-// ============================================================================
-// Tab Slice
-// ============================================================================
-
 export type TabSliceShape = {
   /** Ordered list of open tab file IDs */
   openTabIds: string[]
   /** Currently active tab file ID */
   activeTabId: string | null
-  /** Preview tab file ID (MVP: not enabled, kept null) */
   previewTabId: string | null
-
-  /** Open a file as a tab (and activate it) */
   openTab: (fileId: string) => void
-  /** Close a tab */
   closeTab: (fileId: string) => void
-  /** Activate a tab (without opening) */
   activateTab: (fileId: string) => void
 }
 
 export const createTabSlice: StateCreator<TabSliceShape> = (set, get) => ({
   openTabIds: [],
   activeTabId: null,
-  previewTabId: null, // MVP: Preview mode not enabled
+  previewTabId: null,
 
   openTab: (fileId: string) => {
     const { openTabIds, activeTabId } = get()
@@ -85,19 +65,10 @@ export const createTabSlice: StateCreator<TabSliceShape> = (set, get) => ({
   },
 })
 
-// ============================================================================
-// File Tree Slice
-// ============================================================================
-
 export type FileTreeSliceShape = {
-  /** Set of expanded folder IDs (controlled by react-arborist) */
   expandedFolderIds: Set<string>
-
-  /** Update expanded folder IDs (controlled mode) */
   setExpandedFolderIds: (ids: Set<string>) => void
-  /** Toggle a folder's expanded state */
   toggleFolder: (folderId: string) => void
-  /** Reveal a file by expanding all ancestor folders */
   revealFile: (ancestorFolderIds: string[]) => void
 }
 
@@ -122,27 +93,16 @@ export const createFileTreeSlice: StateCreator<FileTreeSliceShape> = (set, get)
   revealFile: (ancestorFolderIds: string[]) => {
     const { expandedFolderIds } = get()
     const newSet = new Set(expandedFolderIds)
-    // Expand all ancestors
     ancestorFolderIds.forEach(id => newSet.add(id))
     set({ expandedFolderIds: newSet })
   },
 })
 
-// ============================================================================
-// Dirty State Slice
-// ============================================================================
-
 export type DirtySliceShape = {
-  /** Map of fileId -> edited content (only stores modified files) */
   dirtyContents: Map<string, string>
-
-  /** Set draft content for a file (marks as dirty) */
   setDraftContent: (fileId: string, content: string) => void
-  /** Clear draft content (after successful save) */
   clearDraftContent: (fileId: string) => void
-  /** Check if a file has unsaved changes */
   isDirty: (fileId: string) => boolean
-  /** Get draft content for a file (or undefined if not dirty) */
   getDraftContent: (fileId: string) => string | undefined
 }
 
@@ -172,19 +132,12 @@ export const createDirtySlice: StateCreator<DirtySliceShape> = (set, get) => ({
   },
 })
 
-// ============================================================================
-// File Operations Menu Slice
-// ============================================================================
-
 export type FileOperationsMenuSliceShape = {
-  /** Context menu state (right-click) - null when closed */
   contextMenu: {
     top: number
     left: number
     nodeId: string
   } | null
-
-  /** Set or clear context menu */
   setContextMenu: (menu: FileOperationsMenuSliceShape['contextMenu']) => void
 }
 
@@ -196,24 +149,15 @@ export const createFileOperationsMenuSlice: StateCreator<FileOperationsMenuSlice
   },
 })
 
-// ============================================================================
-// Combined Store Shape
-// ============================================================================
-
 export type SkillEditorShape
   = TabSliceShape
     & FileTreeSliceShape
     & DirtySliceShape
     & FileOperationsMenuSliceShape
     & {
-    /** Reset all state (called when appId changes) */
       reset: () => void
     }
 
-// ============================================================================
-// Store Factory
-// ============================================================================
-
 export const createSkillEditorStore = (): StoreApi<SkillEditorShape> => {
   return createStore<SkillEditorShape>((...args) => ({
     ...createTabSlice(...args),
@@ -235,10 +179,6 @@ export const createSkillEditorStore = (): StoreApi<SkillEditorShape> => {
   }))
 }
 
-// ============================================================================
-// Context and Hooks
-// ============================================================================
-
 export type SkillEditorStore = StoreApi<SkillEditorShape>
 
 export const SkillEditorContext = React.createContext<SkillEditorStore | null>(null)
diff --git a/web/app/components/workflow/skill/type.ts b/web/app/components/workflow/skill/type.ts
index fb6ce18b29..f3931a8c91 100644
--- a/web/app/components/workflow/skill/type.ts
+++ b/web/app/components/workflow/skill/type.ts
@@ -1,164 +1,13 @@
 import type { AppAssetTreeView } from '@/types/app-asset'
 
-/**
- * Skill Editor Types
- *
- * This file defines types for the Skill Editor component.
- * Primary data comes from API (AppAssetTreeView), these types provide
- * local aliases and helper types for component props.
- */
-
-// ============================================================================
-// Re-export API types for convenience
-// ============================================================================
-
-export type { AppAssetNode, AppAssetTreeView, AssetNodeType } from '@/types/app-asset'
-
-// ============================================================================
-// Tree Node Types (for react-arborist)
-// ============================================================================
-
-/**
- * Tree node data type for react-arborist
- * This matches AppAssetTreeView structure directly
- */
 export type TreeNodeData = AppAssetTreeView
 
-// ============================================================================
-// Tab Types
-// ============================================================================
-
 export type SkillTabType = 'start' | 'file'
 
 export type SkillTabItem = {
-  /** Unique ID (for 'file' type, this is the fileId; for 'start', a constant) */
   id: string
-  /** Tab type: 'start' for home tab, 'file' for file tabs */
   type: SkillTabType
-  /** Display name (file name or 'Start') */
   name: string
-  /** File extension (for file type only) */
   extension?: string
-  /** Whether this tab has unsaved changes */
   isDirty?: boolean
 }
-
-// ============================================================================
-// Utility Functions
-// ============================================================================
-
-/**
- * Convert API tree data to a flat map for quick lookup
- * @param nodes - Tree nodes from API (nested structure)
- * @returns Map of nodeId -> node data
- */
-export function buildNodeMap(nodes: AppAssetTreeView[]): Map<string, AppAssetTreeView> {
-  const map = new Map<string, AppAssetTreeView>()
-
-  function traverse(nodeList: AppAssetTreeView[]) {
-    for (const node of nodeList) {
-      map.set(node.id, node)
-      if (node.children && node.children.length > 0)
-        traverse(node.children)
-    }
-  }
-
-  traverse(nodes)
-  return map
-}
-
-/**
- * Get ancestor folder IDs for a given node
- * Used for revealFile to expand all parent folders
- * @param nodeId - Target node ID
- * @param nodes - Tree nodes from API
- * @returns Array of ancestor folder IDs (from root to parent)
- */
-export function getAncestorIds(nodeId: string, nodes: AppAssetTreeView[]): string[] {
-  const ancestors: string[] = []
-
-  function findPath(nodeList: AppAssetTreeView[], targetId: string, currentPath: string[]): boolean {
-    for (const node of nodeList) {
-      if (node.id === targetId) {
-        ancestors.push(...currentPath)
-        return true
-      }
-      if (node.children && node.children.length > 0) {
-        const newPath = node.node_type === 'folder' ? [...currentPath, node.id] : currentPath
-        if (findPath(node.children, targetId, newPath))
-          return true
-      }
-    }
-    return false
-  }
-
-  findPath(nodes, nodeId, [])
-  return ancestors
-}
-
-/**
- * Convert expanded folder IDs set to react-arborist opens object
- * @param expandedIds - Set of expanded folder IDs
- * @returns Object for react-arborist opens prop
- */
-export function toOpensObject(expandedIds: Set<string>): Record<string, boolean> {
-  return Object.fromEntries([...expandedIds].map(id => [id, true]))
-}
-
-/**
- * Find a node by ID in the tree (recursive search)
- * @param nodes - Tree nodes from API (nested structure)
- * @param nodeId - Target node ID
- * @returns Node if found, null otherwise
- */
-export function findNodeById(
-  nodes: AppAssetTreeView[],
-  nodeId: string,
-): AppAssetTreeView | null {
-  for (const node of nodes) {
-    if (node.id === nodeId)
-      return node
-    if (node.children && node.children.length > 0) {
-      const found = findNodeById(node.children, nodeId)
-      if (found)
-        return found
-    }
-  }
-  return null
-}
-
-/**
- * Get all descendant file IDs recursively (for tab cleanup on node delete)
- * @param nodeId - Target node ID (file or folder)
- * @param nodes - Tree nodes from API
- * @returns Array of file IDs to close (the node itself if file, or all descendants if folder)
- */
-export function getAllDescendantFileIds(
-  nodeId: string,
-  nodes: AppAssetTreeView[],
-): string[] {
-  const targetNode = findNodeById(nodes, nodeId)
-  if (!targetNode)
-    return []
-
-  // If deleting a file, return just that file's ID
-  if (targetNode.node_type === 'file')
-    return [targetNode.id]
-
-  // For folders, collect all descendant files
-  const fileIds: string[] = []
-
-  function collectFileIds(nodeList: AppAssetTreeView[]) {
-    for (const node of nodeList) {
-      if (node.node_type === 'file')
-        fileIds.push(node.id)
-      if (node.children && node.children.length > 0)
-        collectFileIds(node.children)
-    }
-  }
-
-  if (targetNode.children)
-    collectFileIds(targetNode.children)
-
-  return fileIds
-}
diff --git a/web/app/components/workflow/skill/utils.ts b/web/app/components/workflow/skill/utils/file-utils.ts
similarity index 63%
rename from web/app/components/workflow/skill/utils.ts
rename to web/app/components/workflow/skill/utils/file-utils.ts
index bfcaf2d445..a726ea4cf9 100644
--- a/web/app/components/workflow/skill/utils.ts
+++ b/web/app/components/workflow/skill/utils/file-utils.ts
@@ -7,7 +7,7 @@ const IMAGE_EXTENSIONS = ['png', 'jpg', 'jpeg', 'gif', 'webp', 'svg', 'bmp', 'ic
 const VIDEO_EXTENSIONS = ['mp4', 'mov', 'webm', 'mpeg', 'mpg', 'm4v', 'avi']
 const OFFICE_EXTENSIONS = ['pdf', 'doc', 'docx', 'xls', 'xlsx', 'ppt', 'pptx']
 
-export const getFileExtension = (name?: string, extension?: string) => {
+export function getFileExtension(name?: string, extension?: string): string {
   if (extension)
     return extension.toLowerCase()
   if (!name)
@@ -15,7 +15,7 @@ export const getFileExtension = (name?: string, extension?: string) => {
   return name.split('.').pop()?.toLowerCase() ?? ''
 }
 
-export const getFileIconType = (name: string) => {
+export function getFileIconType(name: string): FileAppearanceTypeEnum {
   const extension = name.split('.').pop()?.toLowerCase() ?? ''
 
   if (MARKDOWN_EXTENSIONS.includes(extension))
@@ -27,37 +27,42 @@ export const getFileIconType = (name: string) => {
   return FileAppearanceTypeEnum.document
 }
 
-export const isMarkdownFile = (extension: string) => MARKDOWN_EXTENSIONS.includes(extension)
-export const isCodeOrTextFile = (extension: string) => CODE_EXTENSIONS.includes(extension) || TEXT_EXTENSIONS.includes(extension)
-export const isImageFile = (extension: string) => IMAGE_EXTENSIONS.includes(extension)
-export const isVideoFile = (extension: string) => VIDEO_EXTENSIONS.includes(extension)
-export const isOfficeFile = (extension: string) => OFFICE_EXTENSIONS.includes(extension)
+export function isMarkdownFile(extension: string): boolean {
+  return MARKDOWN_EXTENSIONS.includes(extension)
+}
 
-/**
- * Get Monaco editor language from file name extension
- */
-export const getFileLanguage = (name: string): string => {
+export function isCodeOrTextFile(extension: string): boolean {
+  return CODE_EXTENSIONS.includes(extension) || TEXT_EXTENSIONS.includes(extension)
+}
+
+export function isImageFile(extension: string): boolean {
+  return IMAGE_EXTENSIONS.includes(extension)
+}
+
+export function isVideoFile(extension: string): boolean {
+  return VIDEO_EXTENSIONS.includes(extension)
+}
+
+export function isOfficeFile(extension: string): boolean {
+  return OFFICE_EXTENSIONS.includes(extension)
+}
+
+export function getFileLanguage(name: string): string {
   const extension = name.split('.').pop()?.toLowerCase() ?? ''
 
   const languageMap: Record<string, string> = {
-    // Markdown
     md: 'markdown',
     markdown: 'markdown',
     mdx: 'markdown',
-    // JSON
     json: 'json',
     jsonl: 'json',
-    // YAML
     yaml: 'yaml',
     yml: 'yaml',
-    // JavaScript/TypeScript
     js: 'javascript',
     jsx: 'javascript',
     ts: 'typescript',
     tsx: 'typescript',
-    // Python
     py: 'python',
-    // Others
     html: 'html',
     css: 'css',
     xml: 'xml',
diff --git a/web/app/components/workflow/skill/utils/tree-utils.ts b/web/app/components/workflow/skill/utils/tree-utils.ts
new file mode 100644
index 0000000000..43382ba302
--- /dev/null
+++ b/web/app/components/workflow/skill/utils/tree-utils.ts
@@ -0,0 +1,86 @@
+import type { AppAssetTreeView } from '@/types/app-asset'
+
+export function buildNodeMap(nodes: AppAssetTreeView[]): Map<string, AppAssetTreeView> {
+  const map = new Map<string, AppAssetTreeView>()
+
+  function traverse(nodeList: AppAssetTreeView[]): void {
+    for (const node of nodeList) {
+      map.set(node.id, node)
+      if (node.children && node.children.length > 0)
+        traverse(node.children)
+    }
+  }
+
+  traverse(nodes)
+  return map
+}
+
+export function getAncestorIds(nodeId: string, nodes: AppAssetTreeView[]): string[] {
+  const ancestors: string[] = []
+
+  function findPath(nodeList: AppAssetTreeView[], targetId: string, currentPath: string[]): boolean {
+    for (const node of nodeList) {
+      if (node.id === targetId) {
+        ancestors.push(...currentPath)
+        return true
+      }
+      if (node.children && node.children.length > 0) {
+        const newPath = node.node_type === 'folder' ? [...currentPath, node.id] : currentPath
+        if (findPath(node.children, targetId, newPath))
+          return true
+      }
+    }
+    return false
+  }
+
+  findPath(nodes, nodeId, [])
+  return ancestors
+}
+
+export function toOpensObject(expandedIds: Set<string>): Record<string, boolean> {
+  return Object.fromEntries([...expandedIds].map(id => [id, true]))
+}
+
+export function findNodeById(
+  nodes: AppAssetTreeView[],
+  nodeId: string,
+): AppAssetTreeView | null {
+  for (const node of nodes) {
+    if (node.id === nodeId)
+      return node
+    if (node.children && node.children.length > 0) {
+      const found = findNodeById(node.children, nodeId)
+      if (found)
+        return found
+    }
+  }
+  return null
+}
+
+export function getAllDescendantFileIds(
+  nodeId: string,
+  nodes: AppAssetTreeView[],
+): string[] {
+  const targetNode = findNodeById(nodes, nodeId)
+  if (!targetNode)
+    return []
+
+  if (targetNode.node_type === 'file')
+    return [targetNode.id]
+
+  const fileIds: string[] = []
+
+  function collectFileIds(nodeList: AppAssetTreeView[]): void {
+    for (const node of nodeList) {
+      if (node.node_type === 'file')
+        fileIds.push(node.id)
+      if (node.children && node.children.length > 0)
+        collectFileIds(node.children)
+    }
+  }
+
+  if (targetNode.children)
+    collectFileIds(targetNode.children)
+
+  return fileIds
+}