diff --git a/web/app/components/workflow/skill/file-item.tsx b/web/app/components/workflow/skill/file-item.tsx
index 198cc8e0e4..be34c326db 100644
--- a/web/app/components/workflow/skill/file-item.tsx
+++ b/web/app/components/workflow/skill/file-item.tsx
@@ -1,12 +1,46 @@
-import type { FC } from 'react'
+import type { FC, ReactNode } from 'react'
 import * as React from 'react'
+import FileTypeIcon from '@/app/components/base/file-uploader/file-type-icon'
+import { FileAppearanceTypeEnum } from '@/app/components/base/file-uploader/types'
+import { cn } from '@/utils/classnames'
+
+type FileItemProps = {
+  name: string
+  prefix?: ReactNode
+  active?: boolean
+}
+
+const getAppearanceType = (name: string) => {
+  const extension = name.split('.').pop()?.toLowerCase() ?? ''
+
+  if (['md', 'markdown', 'mdx'].includes(extension))
+    return FileAppearanceTypeEnum.markdown
+
+  if (['json', 'yaml', 'yml', 'toml', 'js', 'jsx', 'ts', 'tsx', 'py', 'schema'].includes(extension))
+    return FileAppearanceTypeEnum.code
+
+  return FileAppearanceTypeEnum.document
+}
+
+const FileItem: FC<FileItemProps> = ({ name, prefix, active = false }) => {
+  const appearanceType = getAppearanceType(name)
 
-const FileItem: FC = () => {
   return (
     <div
-      className="h-6 rounded bg-gray-100"
+      className={cn(
+        'flex h-6 items-center rounded-md pl-2 pr-1.5 text-text-secondary',
+        active && 'bg-state-base-active text-text-primary',
+      )}
       data-component="file-item"
-    />
+    >
+      {prefix}
+      <div className="flex items-center gap-2 py-0.5">
+        <FileTypeIcon type={appearanceType} size="sm" className={cn(active && 'text-text-primary')} />
+        <span className={cn('system-sm-regular', active && 'font-medium text-text-primary')}>
+          {name}
+        </span>
+      </div>
+    </div>
   )
 }
 
diff --git a/web/app/components/workflow/skill/files.tsx b/web/app/components/workflow/skill/files.tsx
index c9a53dd88e..4c428a2adb 100644
--- a/web/app/components/workflow/skill/files.tsx
+++ b/web/app/components/workflow/skill/files.tsx
@@ -1,15 +1,97 @@
-import type { FC, PropsWithChildren } from 'react'
+'use client'
+import type { FC, ReactNode } from 'react'
+import type { ParentId, ResourceItem, ResourceItemList } from './type'
+import { RiDragDropLine } from '@remixicon/react'
 import * as React from 'react'
+import { useMemo } from 'react'
+import { useTranslation } from 'react-i18next'
+import FileItem from './file-item'
+import FoldItem from './fold-item'
+import { ResourceKind, SKILL_ROOT_ID } from './type'
 
-type FilesProps = PropsWithChildren
+const TreeIndent = ({ depth }: { depth: number }) => {
+  if (depth <= 0)
+    return null
 
-const Files: FC<FilesProps> = ({ children }) => {
   return (
-    <div
-      className="flex flex-1 flex-col gap-2 overflow-auto"
-      data-component="files"
-    >
-      {children}
+    <div className="flex h-full items-stretch">
+      {Array.from({ length: depth }).map((_, index) => (
+        <span key={index} className="relative w-5 shrink-0">
+          <span className="absolute left-1/2 top-0 h-full w-px bg-components-panel-border-subtle" />
+        </span>
+      ))}
+    </div>
+  )
+}
+
+type FilesProps = {
+  items: ResourceItemList
+  activeItemId?: string
+}
+
+const buildChildrenMap = (items: ResourceItemList) => {
+  const map = new Map<ParentId, ResourceItem[]>()
+  items.forEach((item) => {
+    const parentId = item.parent_id ?? null
+    const existing = map.get(parentId)
+    if (existing)
+      existing.push(item)
+    else
+      map.set(parentId, [item])
+  })
+  return map
+}
+
+const Files: FC<FilesProps> = ({ items, activeItemId }) => {
+  const { t } = useTranslation()
+  const childrenMap = useMemo(() => buildChildrenMap(items), [items])
+
+  const renderNodes = (parentId: ParentId, depth: number): ReactNode[] => {
+    const children = childrenMap.get(parentId) || []
+
+    return children.flatMap((item) => {
+      const prefix = <TreeIndent depth={depth} />
+      const isActive = item.id === activeItemId
+      const nodes: ReactNode[] = []
+
+      if (item.kind === ResourceKind.folder) {
+        nodes.push(
+          <FoldItem
+            key={item.id}
+            name={item.name}
+            prefix={prefix}
+            active={isActive}
+            open
+          />,
+        )
+        nodes.push(...renderNodes(item.id, depth + 1))
+      }
+      else {
+        nodes.push(
+          <FileItem
+            key={item.id}
+            name={item.name}
+            prefix={prefix}
+            active={isActive}
+          />,
+        )
+      }
+
+      return nodes
+    })
+  }
+
+  return (
+    <div className="flex min-h-0 flex-1 flex-col" data-component="files">
+      <div className="flex min-h-0 flex-1 flex-col gap-px overflow-auto px-1 pb-0 pt-1">
+        {renderNodes(SKILL_ROOT_ID, 0)}
+      </div>
+      <div className="flex items-center justify-center gap-2 py-4 text-text-quaternary">
+        <RiDragDropLine className="size-4" />
+        <span className="system-xs-regular">
+          {t('skillSidebar.dropTip', { ns: 'workflow' })}
+        </span>
+      </div>
     </div>
   )
 }
diff --git a/web/app/components/workflow/skill/fold-item.tsx b/web/app/components/workflow/skill/fold-item.tsx
index 670199c9ca..93f977a608 100644
--- a/web/app/components/workflow/skill/fold-item.tsx
+++ b/web/app/components/workflow/skill/fold-item.tsx
@@ -1,12 +1,40 @@
-import type { FC } from 'react'
+import type { FC, ReactNode } from 'react'
+import { RiFolder6Line, RiFolderOpenLine } from '@remixicon/react'
 import * as React from 'react'
+import { cn } from '@/utils/classnames'
+
+type FoldItemProps = {
+  name: string
+  prefix?: ReactNode
+  active?: boolean
+  open?: boolean
+}
+
+const FoldItem: FC<FoldItemProps> = ({ name, prefix, active = false, open = false }) => {
+  const Icon = open ? RiFolderOpenLine : RiFolder6Line
 
-const FoldItem: FC = () => {
   return (
     <div
-      className="h-6 rounded bg-gray-100"
+      className={cn(
+        'flex h-6 items-center rounded-md pl-2 pr-1.5 text-text-secondary',
+        active && 'bg-state-base-active text-text-primary',
+      )}
       data-component="fold-item"
-    />
+    >
+      {prefix}
+      <div className="flex items-center gap-2 py-0.5">
+        <Icon
+          className={cn(
+            'size-4',
+            open ? 'text-primary-600' : 'text-text-secondary',
+            active && 'text-text-primary',
+          )}
+        />
+        <span className={cn('system-sm-regular', active && 'font-medium text-text-primary')}>
+          {name}
+        </span>
+      </div>
+    </div>
   )
 }
 
diff --git a/web/app/components/workflow/skill/main.tsx b/web/app/components/workflow/skill/main.tsx
index d560ab5dfb..179b9c4d9c 100644
--- a/web/app/components/workflow/skill/main.tsx
+++ b/web/app/components/workflow/skill/main.tsx
@@ -5,25 +5,22 @@ import EditorArea from './editor-area'
 import EditorBody from './editor-body'
 import EditorTabItem from './editor-tab-item'
 import EditorTabs from './editor-tabs'
-import FileItem from './file-item'
 import Files from './files'
-import FoldItem from './fold-item'
+import { mockSkillItems } from './mock-data'
 import Sidebar from './sidebar'
 import SidebarSearchAdd from './sidebar-search-add'
 import SkillDocEditor from './skill-doc-editor'
 import SkillPageLayout from './skill-page-layout'
 
 const SkillMain: FC = () => {
+  const activeItemId = 'skills/_schemas/email-writer/output-schema'
+
   return (
     <div className="h-full bg-workflow-canvas-workflow-top-bar-1 pl-3 pt-[52px]">
       <SkillPageLayout>
         <Sidebar>
           <SidebarSearchAdd />
-          <Files>
-            <FoldItem />
-            <FileItem />
-            <FileItem />
-          </Files>
+          <Files items={mockSkillItems} activeItemId={activeItemId} />
         </Sidebar>
         <EditorArea>
           <EditorTabs>
diff --git a/web/app/components/workflow/skill/sidebar-search-add.tsx b/web/app/components/workflow/skill/sidebar-search-add.tsx
index 2fc0c1b10e..0e139c0cac 100644
--- a/web/app/components/workflow/skill/sidebar-search-add.tsx
+++ b/web/app/components/workflow/skill/sidebar-search-add.tsx
@@ -1,14 +1,35 @@
+'use client'
 import type { FC } from 'react'
+import { RiAddLine } from '@remixicon/react'
 import * as React from 'react'
+import { useState } from 'react'
+import { useTranslation } from 'react-i18next'
+import Button from '@/app/components/base/button'
+import SearchInput from '@/app/components/base/search-input'
+import { cn } from '@/utils/classnames'
 
 const SidebarSearchAdd: FC = () => {
+  const [value, setValue] = useState('')
+  const { t } = useTranslation()
+
   return (
     <div
-      className="flex items-center gap-2"
+      className="flex items-center gap-1 bg-components-panel-bg p-2"
       data-component="sidebar-search-add"
     >
-      <div className="h-8 flex-1 rounded-md bg-gray-100" />
-      <div className="h-8 w-8 rounded-md bg-gray-100" />
+      <SearchInput
+        value={value}
+        onChange={setValue}
+        className="h-8 flex-1"
+      />
+      <Button
+        variant="primary"
+        size="medium"
+        className={cn('!h-8 !w-8 !px-0')}
+        aria-label={t('operation.add', { ns: 'common' })}
+      >
+        <RiAddLine className="h-4 w-4" />
+      </Button>
     </div>
   )
 }
diff --git a/web/app/components/workflow/skill/sidebar.tsx b/web/app/components/workflow/skill/sidebar.tsx
index 312c150026..03f86f757a 100644
--- a/web/app/components/workflow/skill/sidebar.tsx
+++ b/web/app/components/workflow/skill/sidebar.tsx
@@ -6,7 +6,7 @@ type SidebarProps = PropsWithChildren
 const Sidebar: FC<SidebarProps> = ({ children }) => {
   return (
     <aside
-      className="flex w-[260px] shrink-0 flex-col gap-3 rounded-lg bg-white p-3"
+      className="flex w-[320px] shrink-0 flex-col gap-px overflow-hidden rounded-[10px] border border-components-panel-border-subtle bg-components-panel-bg"
       data-component="sidebar"
     >
       {children}
diff --git a/web/i18n/en-US/workflow.json b/web/i18n/en-US/workflow.json
index 744351e5d3..751d56084f 100644
--- a/web/i18n/en-US/workflow.json
+++ b/web/i18n/en-US/workflow.json
@@ -995,6 +995,7 @@
   "singleRun.testRun": "Test Run",
   "singleRun.testRunIteration": "Test Run Iteration",
   "singleRun.testRunLoop": "Test Run Loop",
+  "skillSidebar.dropTip": "Drop files here to upload",
   "tabs.-": "Default",
   "tabs.addAll": "Add all",
   "tabs.agent": "Agent Strategy",