diff --git a/web-app/src/constants/routes.ts b/web-app/src/constants/routes.ts
index f1f870dd5..16fea5120 100644
--- a/web-app/src/constants/routes.ts
+++ b/web-app/src/constants/routes.ts
@@ -10,6 +10,7 @@ export const route = {
     model_providers: '/settings/providers',
     providers: '/settings/providers/$providerName',
     general: '/settings/general',
+    attachments: '/settings/attachments',
     appearance: '/settings/appearance',
     privacy: '/settings/privacy',
     shortcuts: '/settings/shortcuts',
diff --git a/web-app/src/containers/SettingsMenu.tsx b/web-app/src/containers/SettingsMenu.tsx
index 78389233d..d85c4a03c 100644
--- a/web-app/src/containers/SettingsMenu.tsx
+++ b/web-app/src/containers/SettingsMenu.tsx
@@ -73,6 +73,12 @@ const SettingsMenu = () => {
       hasSubMenu: false,
       isEnabled: true,
     },
+    {
+      title: 'common:attachments',
+      route: route.settings.attachments,
+      hasSubMenu: false,
+      isEnabled: PlatformFeatures[PlatformFeature.ATTACHMENTS],
+    },
     {
       title: 'common:appearance',
       route: route.settings.appearance,
diff --git a/web-app/src/hooks/useAttachments.ts b/web-app/src/hooks/useAttachments.ts
new file mode 100644
index 000000000..62408547e
--- /dev/null
+++ b/web-app/src/hooks/useAttachments.ts
@@ -0,0 +1,45 @@
+import { create } from 'zustand'
+import { persist, createJSONStorage } from 'zustand/middleware'
+import { localStorageKey } from '@/constants/localStorage'
+
+export type AttachmentsSettings = {
+  enabled: boolean
+  maxFileSizeMB: number
+  retrievalLimit: number
+  retrievalThreshold: number
+  chunkSizeTokens: number
+  overlapTokens: number
+}
+
+type AttachmentsStore = AttachmentsSettings & {
+  setEnabled: (v: boolean) => void
+  setMaxFileSizeMB: (v: number) => void
+  setRetrievalLimit: (v: number) => void
+  setRetrievalThreshold: (v: number) => void
+  setChunkSizeTokens: (v: number) => void
+  setOverlapTokens: (v: number) => void
+}
+
+export const useAttachments = create<AttachmentsStore>()(
+  persist(
+    (set) => ({
+      enabled: true,
+      maxFileSizeMB: 20,
+      retrievalLimit: 3,
+      retrievalThreshold: 0.5,
+      chunkSizeTokens: 512,
+      overlapTokens: 64,
+      setEnabled: (v) => set({ enabled: v }),
+      setMaxFileSizeMB: (v) => set({ maxFileSizeMB: Math.max(1, Math.min(200, Math.floor(v))) }),
+      setRetrievalLimit: (v) => set({ retrievalLimit: Math.max(1, Math.min(20, Math.floor(v))) }),
+      setRetrievalThreshold: (v) => set({ retrievalThreshold: Math.max(0, Math.min(1, v)) }),
+      setChunkSizeTokens: (v) => set({ chunkSizeTokens: Math.max(64, Math.min(8192, Math.floor(v))) }),
+      setOverlapTokens: (v) => set({ overlapTokens: Math.max(0, Math.min(1024, Math.floor(v))) }),
+    }),
+    {
+      name: `${localStorageKey.settingGeneral}-attachments`,
+      storage: createJSONStorage(() => localStorage),
+    }
+  )
+)
+
diff --git a/web-app/src/hooks/useTools.ts b/web-app/src/hooks/useTools.ts
index 2ff61eb10..cefa3a5ae 100644
--- a/web-app/src/hooks/useTools.ts
+++ b/web-app/src/hooks/useTools.ts
@@ -5,10 +5,14 @@ import { useAppState } from './useAppState'
 import { useToolAvailable } from './useToolAvailable'
 import { ExtensionManager } from '@/lib/extension'
 import { ExtensionTypeEnum, MCPExtension } from '@janhq/core'
+import { useAttachments } from './useAttachments'
+import { PlatformFeatures } from '@/lib/platform/const'
+import { PlatformFeature } from '@/lib/platform/types'
 
 export const useTools = () => {
   const updateTools = useAppState((state) => state.updateTools)
   const { isDefaultsInitialized, setDefaultDisabledTools, markDefaultsAsInitialized } = useToolAvailable()
+  const attachmentsEnabled = useAttachments((s) => s.enabled)
 
   useEffect(() => {
     async function setTools() {
@@ -19,11 +23,19 @@ export const useTools = () => {
         )
 
         // Fetch tools
-        const data = await getServiceHub().mcp().getTools()
-        updateTools(data)
+        const [mcpTools, ragTools] = await Promise.all([
+          getServiceHub().mcp().getTools(),
+          // Only include RAG tools when attachments feature is enabled
+          useAttachments.getState().enabled && PlatformFeatures[PlatformFeature.ATTACHMENTS]
+            ? getServiceHub().rag().getTools()
+            : Promise.resolve([]),
+        ])
+
+        const combined = [...mcpTools, ...ragTools]
+        updateTools(combined)
 
         // Initialize default disabled tools for new users (only once)
-        if (!isDefaultsInitialized() && data.length > 0 && mcpExtension?.getDefaultDisabledTools) {
+        if (!isDefaultsInitialized() && combined.length > 0 && mcpExtension?.getDefaultDisabledTools) {
           const defaultDisabled = await mcpExtension.getDefaultDisabledTools()
           if (defaultDisabled.length > 0) {
             setDefaultDisabledTools(defaultDisabled)
@@ -31,7 +43,7 @@ export const useTools = () => {
           }
         }
       } catch (error) {
-        console.error('Failed to fetch MCP tools:', error)
+        console.error('Failed to fetch tools:', error)
       }
     }
     setTools()
@@ -41,9 +53,14 @@ export const useTools = () => {
       // Unsubscribe from the event when the component unmounts
       unsubscribe = unsub
     }).catch((error) => {
-      console.error('Failed to set up MCP update listener:', error)
+      console.error('Failed to set up tools update listener:', error)
     })
     return unsubscribe
     // eslint-disable-next-line react-hooks/exhaustive-deps
   }, [])
+
+  // Refresh tools when attachments feature toggles
+  useEffect(() => {
+    getServiceHub().events().emit(SystemEvent.MCP_UPDATE)
+  }, [attachmentsEnabled])
 }
diff --git a/web-app/src/lib/platform/const.ts b/web-app/src/lib/platform/const.ts
index d38455a49..5f004235a 100644
--- a/web-app/src/lib/platform/const.ts
+++ b/web-app/src/lib/platform/const.ts
@@ -78,6 +78,10 @@ export const PlatformFeatures: Record<PlatformFeature, boolean> = {
   // First message persisted thread - enabled for web only
   [PlatformFeature.FIRST_MESSAGE_PERSISTED_THREAD]: !isPlatformTauri(),
 
-    // Temporary chat mode - enabled for web only
+  // Temporary chat mode - enabled for web only
   [PlatformFeature.TEMPORARY_CHAT]: !isPlatformTauri(),
+
+  // Attachments/RAG UI and tooling - desktop only for now
+  [PlatformFeature.ATTACHMENTS]:
+    isPlatformTauri() && !isPlatformIOS() && !isPlatformAndroid(),
 }
diff --git a/web-app/src/lib/platform/types.ts b/web-app/src/lib/platform/types.ts
index 08d78eeca..823105e13 100644
--- a/web-app/src/lib/platform/types.ts
+++ b/web-app/src/lib/platform/types.ts
@@ -71,4 +71,7 @@ export enum PlatformFeature {
 
   // Temporary chat mode - web-only feature for ephemeral conversations like ChatGPT
   TEMPORARY_CHAT = 'temporaryChat',
+
+  // Attachments/RAG UI and tooling (desktop-only for now)
+  ATTACHMENTS = 'attachments',
 }
diff --git a/web-app/src/locales/en/common.json b/web-app/src/locales/en/common.json
index 2eca7a699..5e0679bd6 100644
--- a/web-app/src/locales/en/common.json
+++ b/web-app/src/locales/en/common.json
@@ -5,6 +5,7 @@
   "local_api_server": "Local API Server",
   "https_proxy": "HTTPS Proxy",
   "extensions": "Extensions",
+  "attachments": "Attachments",
   "general": "General",
   "settings": "Settings",
   "modelProviders": "Model Providers",
@@ -369,4 +370,3 @@
     }
   }
 }
-
diff --git a/web-app/src/locales/en/settings.json b/web-app/src/locales/en/settings.json
index afc6d6a47..dc1e34f76 100644
--- a/web-app/src/locales/en/settings.json
+++ b/web-app/src/locales/en/settings.json
@@ -253,6 +253,25 @@
   "extensions": {
     "title": "Extensions"
   },
+  "attachments": {
+    "subtitle": "Configure document attachments, size limits, and retrieval behavior.",
+    "featureTitle": "Feature",
+    "enable": "Enable Attachments",
+    "enableDesc": "Allow uploading and indexing documents for retrieval.",
+    "limitsTitle": "Limits",
+    "maxFile": "Max File Size (MB)",
+    "maxFileDesc": "Maximum size per file. Enforced at upload and processing time.",
+    "retrievalTitle": "Retrieval",
+    "topK": "Top-K",
+    "topKDesc": "Maximum citations to return.",
+    "threshold": "Affinity Threshold",
+    "thresholdDesc": "Minimum similarity score to consider relevant (0-1).",
+    "chunkingTitle": "Chunking",
+    "chunkSize": "Chunk Size (tokens)",
+    "chunkSizeDesc": "Approximate max tokens per chunk for embeddings.",
+    "chunkOverlap": "Overlap (tokens)",
+    "chunkOverlapDesc": "Token overlap between consecutive chunks."
+  },
   "dialogs": {
     "changeDataFolder": {
       "title": "Change Data Folder Location",
diff --git a/web-app/src/routeTree.gen.ts b/web-app/src/routeTree.gen.ts
index 13b55798a..6d2a97d0b 100644
--- a/web-app/src/routeTree.gen.ts
+++ b/web-app/src/routeTree.gen.ts
@@ -26,6 +26,7 @@ import { Route as SettingsHttpsProxyImport } from './routes/settings/https-proxy
 import { Route as SettingsHardwareImport } from './routes/settings/hardware'
 import { Route as SettingsGeneralImport } from './routes/settings/general'
 import { Route as SettingsExtensionsImport } from './routes/settings/extensions'
+import { Route as SettingsAttachmentsImport } from './routes/settings/attachments'
 import { Route as SettingsAppearanceImport } from './routes/settings/appearance'
 import { Route as ProjectProjectIdImport } from './routes/project/$projectId'
 import { Route as LocalApiServerLogsImport } from './routes/local-api-server/logs'
@@ -126,6 +127,12 @@ const SettingsExtensionsRoute = SettingsExtensionsImport.update({
   getParentRoute: () => rootRoute,
 } as any)
 
+const SettingsAttachmentsRoute = SettingsAttachmentsImport.update({
+  id: '/settings/attachments',
+  path: '/settings/attachments',
+  getParentRoute: () => rootRoute,
+} as any)
+
 const SettingsAppearanceRoute = SettingsAppearanceImport.update({
   id: '/settings/appearance',
   path: '/settings/appearance',
@@ -229,6 +236,13 @@ declare module '@tanstack/react-router' {
       preLoaderRoute: typeof SettingsAppearanceImport
       parentRoute: typeof rootRoute
     }
+    '/settings/attachments': {
+      id: '/settings/attachments'
+      path: '/settings/attachments'
+      fullPath: '/settings/attachments'
+      preLoaderRoute: typeof SettingsAttachmentsImport
+      parentRoute: typeof rootRoute
+    }
     '/settings/extensions': {
       id: '/settings/extensions'
       path: '/settings/extensions'
@@ -341,6 +355,7 @@ export interface FileRoutesByFullPath {
   '/local-api-server/logs': typeof LocalApiServerLogsRoute
   '/project/$projectId': typeof ProjectProjectIdRoute
   '/settings/appearance': typeof SettingsAppearanceRoute
+  '/settings/attachments': typeof SettingsAttachmentsRoute
   '/settings/extensions': typeof SettingsExtensionsRoute
   '/settings/general': typeof SettingsGeneralRoute
   '/settings/hardware': typeof SettingsHardwareRoute
@@ -366,6 +381,7 @@ export interface FileRoutesByTo {
   '/local-api-server/logs': typeof LocalApiServerLogsRoute
   '/project/$projectId': typeof ProjectProjectIdRoute
   '/settings/appearance': typeof SettingsAppearanceRoute
+  '/settings/attachments': typeof SettingsAttachmentsRoute
   '/settings/extensions': typeof SettingsExtensionsRoute
   '/settings/general': typeof SettingsGeneralRoute
   '/settings/hardware': typeof SettingsHardwareRoute
@@ -392,6 +408,7 @@ export interface FileRoutesById {
   '/local-api-server/logs': typeof LocalApiServerLogsRoute
   '/project/$projectId': typeof ProjectProjectIdRoute
   '/settings/appearance': typeof SettingsAppearanceRoute
+  '/settings/attachments': typeof SettingsAttachmentsRoute
   '/settings/extensions': typeof SettingsExtensionsRoute
   '/settings/general': typeof SettingsGeneralRoute
   '/settings/hardware': typeof SettingsHardwareRoute
@@ -419,6 +436,7 @@ export interface FileRouteTypes {
     | '/local-api-server/logs'
     | '/project/$projectId'
     | '/settings/appearance'
+    | '/settings/attachments'
     | '/settings/extensions'
     | '/settings/general'
     | '/settings/hardware'
@@ -443,6 +461,7 @@ export interface FileRouteTypes {
     | '/local-api-server/logs'
     | '/project/$projectId'
     | '/settings/appearance'
+    | '/settings/attachments'
     | '/settings/extensions'
     | '/settings/general'
     | '/settings/hardware'
@@ -467,6 +486,7 @@ export interface FileRouteTypes {
     | '/local-api-server/logs'
     | '/project/$projectId'
     | '/settings/appearance'
+    | '/settings/attachments'
     | '/settings/extensions'
     | '/settings/general'
     | '/settings/hardware'
@@ -493,6 +513,7 @@ export interface RootRouteChildren {
   LocalApiServerLogsRoute: typeof LocalApiServerLogsRoute
   ProjectProjectIdRoute: typeof ProjectProjectIdRoute
   SettingsAppearanceRoute: typeof SettingsAppearanceRoute
+  SettingsAttachmentsRoute: typeof SettingsAttachmentsRoute
   SettingsExtensionsRoute: typeof SettingsExtensionsRoute
   SettingsGeneralRoute: typeof SettingsGeneralRoute
   SettingsHardwareRoute: typeof SettingsHardwareRoute
@@ -518,6 +539,7 @@ const rootRouteChildren: RootRouteChildren = {
   LocalApiServerLogsRoute: LocalApiServerLogsRoute,
   ProjectProjectIdRoute: ProjectProjectIdRoute,
   SettingsAppearanceRoute: SettingsAppearanceRoute,
+  SettingsAttachmentsRoute: SettingsAttachmentsRoute,
   SettingsExtensionsRoute: SettingsExtensionsRoute,
   SettingsGeneralRoute: SettingsGeneralRoute,
   SettingsHardwareRoute: SettingsHardwareRoute,
@@ -552,6 +574,7 @@ export const routeTree = rootRoute
         "/local-api-server/logs",
         "/project/$projectId",
         "/settings/appearance",
+        "/settings/attachments",
         "/settings/extensions",
         "/settings/general",
         "/settings/hardware",
@@ -592,6 +615,9 @@ export const routeTree = rootRoute
     "/settings/appearance": {
       "filePath": "settings/appearance.tsx"
     },
+    "/settings/attachments": {
+      "filePath": "settings/attachments.tsx"
+    },
     "/settings/extensions": {
       "filePath": "settings/extensions.tsx"
     },
diff --git a/web-app/src/routes/settings/attachments.tsx b/web-app/src/routes/settings/attachments.tsx
new file mode 100644
index 000000000..bd4635cd1
--- /dev/null
+++ b/web-app/src/routes/settings/attachments.tsx
@@ -0,0 +1,185 @@
+import { createFileRoute } from '@tanstack/react-router'
+import { route } from '@/constants/routes'
+import SettingsMenu from '@/containers/SettingsMenu'
+import HeaderPage from '@/containers/HeaderPage'
+import { Card, CardItem } from '@/containers/Card'
+import { Switch } from '@/components/ui/switch'
+import { Input } from '@/components/ui/input'
+import { useAttachments } from '@/hooks/useAttachments'
+import { useTranslation } from '@/i18n/react-i18next-compat'
+import { PlatformGuard } from '@/lib/platform/PlatformGuard'
+import { PlatformFeature } from '@/lib/platform/types'
+
+// eslint-disable-next-line @typescript-eslint/no-explicit-any
+export const Route = createFileRoute(route.settings.attachments as any)({
+  component: AttachmentsSettings,
+})
+
+function NumberInput({
+  value,
+  onChange,
+  min,
+  max,
+  step = 1,
+}: {
+  value: number
+  onChange: (v: number) => void
+  min?: number
+  max?: number
+  step?: number
+}) {
+  return (
+    <Input
+      type="number"
+      value={value}
+      min={min}
+      max={max}
+      step={step}
+      onChange={(e) => onChange(Number(e.target.value))}
+      className="w-28"
+    />
+  )
+}
+
+function AttachmentsSettings() {
+  const { t } = useTranslation()
+  const {
+    enabled,
+    maxFileSizeMB,
+    retrievalLimit,
+    retrievalThreshold,
+    chunkSizeTokens,
+    overlapTokens,
+    setEnabled,
+    setMaxFileSizeMB,
+    setRetrievalLimit,
+    setRetrievalThreshold,
+    setChunkSizeTokens,
+    setOverlapTokens,
+  } = useAttachments()
+
+  return (
+    <PlatformGuard feature={PlatformFeature.ATTACHMENTS}>
+      <div className="flex h-full w-full">
+        <div className="hidden sm:flex">
+          <SettingsMenu />
+        </div>
+        <div className="flex-1">
+        <HeaderPage
+          title={t('common:attachments') || 'Attachments'}
+          subtitle={
+            t('settings:attachments.subtitle') ||
+            'Configure document attachments, size limits, and retrieval behavior.'
+          }
+        />
+        <div className="px-6 py-3 space-y-4">
+          <Card title={t('settings:attachments.featureTitle') || 'Feature'}>
+            <CardItem
+              title={t('settings:attachments.enable') || 'Enable Attachments'}
+              description={
+                t('settings:attachments.enableDesc') ||
+                'Allow uploading and indexing documents for retrieval.'
+              }
+              actions={
+                <Switch checked={enabled} onCheckedChange={setEnabled} />
+              }
+            />
+          </Card>
+
+          <Card title={t('settings:attachments.limitsTitle') || 'Limits'}>
+            <CardItem
+              title={t('settings:attachments.maxFile') || 'Max File Size (MB)'}
+              description={
+                t('settings:attachments.maxFileDesc') ||
+                'Maximum size per file. Enforced at upload and processing time.'
+              }
+              actions={
+                <NumberInput
+                  value={maxFileSizeMB}
+                  onChange={setMaxFileSizeMB}
+                  min={1}
+                  max={200}
+                />
+              }
+            />
+          </Card>
+
+          <Card title={t('settings:attachments.retrievalTitle') || 'Retrieval'}>
+            <CardItem
+              title={t('settings:attachments.topK') || 'Top-K'}
+              description={
+                t('settings:attachments.topKDesc') || 'Maximum citations to return.'
+              }
+              actions={
+                <NumberInput
+                  value={retrievalLimit}
+                  onChange={setRetrievalLimit}
+                  min={1}
+                  max={10}
+                />
+              }
+            />
+            <CardItem
+              title={
+                t('settings:attachments.threshold') || 'Affinity Threshold'
+              }
+              description={
+                t('settings:attachments.thresholdDesc') ||
+                'Minimum similarity score to consider relevant (0-1).'
+              }
+              actions={
+                <Input
+                  type="number"
+                  value={retrievalThreshold}
+                  min={0}
+                  max={1}
+                  step={0.01}
+                  onChange={(e) => setRetrievalThreshold(Number(e.target.value))}
+                  className="w-28"
+                />
+              }
+            />
+          </Card>
+
+          <Card title={t('settings:attachments.chunkingTitle') || 'Chunking'}>
+            <CardItem
+              title={
+                t('settings:attachments.chunkSize') || 'Chunk Size (tokens)'
+              }
+              description={
+                t('settings:attachments.chunkSizeDesc') ||
+                'Approximate max tokens per chunk for embeddings.'
+              }
+              actions={
+                <NumberInput
+                  value={chunkSizeTokens}
+                  onChange={setChunkSizeTokens}
+                  min={64}
+                  max={8192}
+                />
+              }
+            />
+            <CardItem
+              title={
+                t('settings:attachments.chunkOverlap') || 'Overlap (tokens)'
+              }
+              description={
+                t('settings:attachments.chunkOverlapDesc') ||
+                'Token overlap between consecutive chunks.'
+              }
+              actions={
+                <NumberInput
+                  value={overlapTokens}
+                  onChange={setOverlapTokens}
+                  min={0}
+                  max={1024}
+                />
+              }
+            />
+          </Card>
+        </div>
+      </div>
+      </div>
+    </PlatformGuard>
+  )
+}
diff --git a/web-app/src/services/index.ts b/web-app/src/services/index.ts
index 0bfba90e6..bd9fcc57b 100644
--- a/web-app/src/services/index.ts
+++ b/web-app/src/services/index.ts
@@ -27,6 +27,8 @@ import { DefaultPathService } from './path/default'
 import { DefaultCoreService } from './core/default'
 import { DefaultDeepLinkService } from './deeplink/default'
 import { DefaultProjectsService } from './projects/default'
+import { DefaultRAGService } from './rag/default'
+import type { RAGService } from './rag/types'
 
 // Import service types
 import type { ThemeService } from './theme/types'
@@ -70,6 +72,7 @@ export interface ServiceHub {
   core(): CoreService
   deeplink(): DeepLinkService
   projects(): ProjectsService
+  rag(): RAGService
 }
 
 class PlatformServiceHub implements ServiceHub {
@@ -92,6 +95,7 @@ class PlatformServiceHub implements ServiceHub {
   private coreService: CoreService = new DefaultCoreService()
   private deepLinkService: DeepLinkService = new DefaultDeepLinkService()
   private projectsService: ProjectsService = new DefaultProjectsService()
+  private ragService: RAGService = new DefaultRAGService()
   private initialized = false
 
   /**
@@ -302,6 +306,11 @@ class PlatformServiceHub implements ServiceHub {
     this.ensureInitialized()
     return this.projectsService
   }
+
+  rag(): RAGService {
+    this.ensureInitialized()
+    return this.ragService
+  }
 }
 
 export async function initializeServiceHub(): Promise<ServiceHub> {
diff --git a/web-app/src/services/rag/default.ts b/web-app/src/services/rag/default.ts
new file mode 100644
index 000000000..4af79d2cd
--- /dev/null
+++ b/web-app/src/services/rag/default.ts
@@ -0,0 +1,9 @@
+import type { RAGService } from './types'
+import type { MCPTool } from '@janhq/core'
+
+export class DefaultRAGService implements RAGService {
+  async getTools(): Promise<MCPTool[]> {
+    // Temporarily return no tools; real tools will be provided by rag-extension later
+    return []
+  }
+}
diff --git a/web-app/src/services/rag/types.ts b/web-app/src/services/rag/types.ts
new file mode 100644
index 000000000..f3b53da1e
--- /dev/null
+++ b/web-app/src/services/rag/types.ts
@@ -0,0 +1,7 @@
+import { MCPTool } from '@janhq/core'
+
+export interface RAGService {
+  // Return tools exposed by RAG-related extensions (e.g., retrieval, list_attachments)
+  getTools(): Promise<MCPTool[]>
+}
+