Feat: web temporary chat (#6650)

* temporray chat stage1

* temporary page in root

* temporary chat

* handle redirection properly
`

* temporary chat header

* Update extensions-web/src/conversational-web/extension.ts

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

* update routetree

* better error handling

* fix strecthed assitant on desktop

* update yarn link to workspace for better link consistency

---------

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

extensions-web/src/conversational-web/extension.ts

@@ -11,6 +11,9 @@ import {
 } from '@janhq/core'
 import { RemoteApi } from './api'
 import { getDefaultAssistant, ObjectParser, combineConversationItemsToMessages } from './utils'
+import { ApiError } from '../shared/types/errors'
+
+const CONVERSATION_NOT_FOUND_EVENT = 'conversation-not-found'
 
 export default class ConversationalExtensionWeb extends ConversationalExtension {
   private remoteApi: RemoteApi | undefined
@@ -111,6 +114,15 @@ export default class ConversationalExtensionWeb extends ConversationalExtension
       return messages
     } catch (error) {
       console.error('Failed to list messages:', error)
+      // Check if it's a 404 error (conversation not found)
+      if (error instanceof ApiError && error.isNotFound()) {
+        // Trigger a navigation event to redirect to home
+        // We'll use a custom event that the web app can listen to
+        window.dispatchEvent(new CustomEvent(CONVERSATION_NOT_FOUND_EVENT, {
+          detail: { threadId, error: error.message }
+        }))
+      }
+
       return []
     }
   }

extensions-web/src/jan-provider-web/api.ts

@@ -5,9 +5,45 @@
 
 import { getSharedAuthService, JanAuthService } from '../shared'
 import { JanModel, janProviderStore } from './store'
+import { ApiError } from '../shared/types/errors'
 
 // JAN_API_BASE is defined in vite.config.ts
 
+// Constants
+const TEMPORARY_CHAT_ID = 'temporary-chat'
+
+/**
+ * Determines the appropriate API endpoint and request payload based on chat type
+ * @param request - The chat completion request
+ * @returns Object containing endpoint URL and processed request payload
+ */
+function getChatCompletionConfig(request: JanChatCompletionRequest, stream: boolean = false) {
+  const isTemporaryChat = request.conversation_id === TEMPORARY_CHAT_ID
+
+  // For temporary chats, use the stateless /chat/completions endpoint
+  // For regular conversations, use the stateful /conv/chat/completions endpoint
+  const endpoint = isTemporaryChat
+    ? `${JAN_API_BASE}/chat/completions`
+    : `${JAN_API_BASE}/conv/chat/completions`
+
+  const payload = {
+    ...request,
+    stream,
+    ...(isTemporaryChat ? {
+      // For temporary chat: don't store anything, remove conversation metadata
+      conversation_id: undefined,
+    } : {
+      // For regular chat: store everything, use conversation metadata
+      store: true,
+      store_reasoning: true,
+      conversation: request.conversation_id,
+      conversation_id: undefined,
+    })
+  }
+
+  return { endpoint, payload, isTemporaryChat }
+}
+
 export interface JanModelsResponse {
   object: string
   data: JanModel[]
@@ -102,7 +138,8 @@ export class JanApiClient {
       
       return models
     } catch (error) {
-      const errorMessage = error instanceof Error ? error.message : 'Failed to fetch models'
+      const errorMessage = error instanceof ApiError ? error.message :
+                          error instanceof Error ? error.message : 'Failed to fetch models'
       janProviderStore.setError(errorMessage)
       janProviderStore.setLoadingModels(false)
       throw error
@@ -115,22 +152,18 @@ export class JanApiClient {
     try {
       janProviderStore.clearError()
 
+      const { endpoint, payload } = getChatCompletionConfig(request, false)
+
       return await this.authService.makeAuthenticatedRequest<JanChatCompletionResponse>(
-        `${JAN_API_BASE}/conv/chat/completions`,
+        endpoint,
         {
           method: 'POST',
-          body: JSON.stringify({
+          body: JSON.stringify(payload),
-            ...request,
-            stream: false,
-            store: true,
-            store_reasoning: true,
-            conversation: request.conversation_id,
-            conversation_id: undefined,
-          }),
         }
       )
     } catch (error) {
-      const errorMessage = error instanceof Error ? error.message : 'Failed to create chat completion'
+      const errorMessage = error instanceof ApiError ? error.message :
+                          error instanceof Error ? error.message : 'Failed to create chat completion'
       janProviderStore.setError(errorMessage)
       throw error
     }
@@ -146,21 +179,15 @@ export class JanApiClient {
       janProviderStore.clearError()
 
       const authHeader = await this.authService.getAuthHeader()
+      const { endpoint, payload } = getChatCompletionConfig(request, true)
 
-      const response = await fetch(`${JAN_API_BASE}/conv/chat/completions`, {
+      const response = await fetch(endpoint, {
         method: 'POST',
         headers: {
           'Content-Type': 'application/json',
           ...authHeader,
         },
-        body: JSON.stringify({
+        body: JSON.stringify(payload),
-          ...request,
-          stream: true,
-          store: true,
-          store_reasoning: true,
-          conversation: request.conversation_id,
-          conversation_id: undefined,
-        }),
       })
 
       if (!response.ok) {
@@ -216,7 +243,8 @@ export class JanApiClient {
         reader.releaseLock()
       }
     } catch (error) {
-      const err = error instanceof Error ? error : new Error('Unknown error occurred')
+      const err = error instanceof ApiError ? error :
+                 error instanceof Error ? error : new Error('Unknown error occurred')
       janProviderStore.setError(err.message)
       onError?.(err)
       throw err
@@ -230,7 +258,8 @@ export class JanApiClient {
       await this.getModels()
       console.log('Jan API client initialized successfully')
     } catch (error) {
-      const errorMessage = error instanceof Error ? error.message : 'Failed to initialize API client'
+      const errorMessage = error instanceof ApiError ? error.message :
+                          error instanceof Error ? error.message : 'Failed to initialize API client'
       janProviderStore.setError(errorMessage)
       throw error
     } finally {

extensions-web/src/jan-provider-web/provider.ts

@@ -15,6 +15,7 @@ import {
 } from '@janhq/core' // cspell: disable-line
 import { janApiClient, JanChatMessage } from './api'
 import { janProviderStore } from './store'
+import { ApiError } from '../shared/types/errors'
 
 // Jan models support tools via MCP
 const JAN_MODEL_CAPABILITIES = ['tools'] as const
@@ -192,7 +193,8 @@ export default class JanProviderWeb extends AIEngine {
       console.error(`Failed to unload Jan session ${sessionId}:`, error)
       return {
         success: false,
-        error: error instanceof Error ? error.message : 'Unknown error',
+        error: error instanceof ApiError ? error.message :
+               error instanceof Error ? error.message : 'Unknown error',
       }
     }
   }

extensions-web/src/shared/auth/service.ts

@@ -16,6 +16,7 @@ import { logoutUser, refreshToken, guestLogin } from './api'
 import { AuthProviderRegistry } from './registry'
 import { AuthBroadcast } from './broadcast'
 import type { ProviderType } from './providers'
+import { ApiError } from '../types/errors'
 
 const authProviderRegistry = new AuthProviderRegistry()
 
@@ -160,7 +161,7 @@ export class JanAuthService {
       this.tokenExpiryTime = Date.now() + tokens.expires_in * 1000
     } catch (error) {
       console.error('Failed to refresh access token:', error)
-      if (error instanceof Error && error.message.includes('401')) {
+      if (error instanceof ApiError && error.isStatus(401)) {
         await this.handleSessionExpired()
       }
       throw error
@@ -305,9 +306,7 @@ export class JanAuthService {
 
       if (!response.ok) {
         const errorText = await response.text()
-        throw new Error(
+        throw new ApiError(response.status, response.statusText, errorText)
-          `API request failed: ${response.status} ${response.statusText} - ${errorText}`
-        )
       }
 
       return response.json()
@@ -418,7 +417,7 @@ export class JanAuthService {
       )
     } catch (error) {
       console.error('Failed to fetch user profile:', error)
-      if (error instanceof Error && error.message.includes('401')) {
+      if (error instanceof ApiError && error.isStatus(401)) {
         // Authentication failed - handle session expiry
         await this.handleSessionExpired()
         return null

extensions-web/src/shared/types/errors.ts

@@ -0,0 +1,50 @@
+/**
+ * Shared error types for API responses
+ */
+
+export class ApiError extends Error {
+  public readonly status: number
+  public readonly statusText: string
+  public readonly responseText: string
+
+  constructor(status: number, statusText: string, responseText: string, message?: string) {
+    super(message || `API request failed: ${status} ${statusText} - ${responseText}`)
+    this.name = 'ApiError'
+    this.status = status
+    this.statusText = statusText
+    this.responseText = responseText
+
+    // Maintains proper stack trace for where our error was thrown (only available on V8)
+    if ((Error as any).captureStackTrace) {
+      (Error as any).captureStackTrace(this, ApiError)
+    }
+  }
+
+  /**
+   * Check if this is a specific HTTP status code
+   */
+  isStatus(code: number): boolean {
+    return this.status === code
+  }
+
+  /**
+   * Check if this is a 404 Not Found error
+   */
+  isNotFound(): boolean {
+    return this.status === 404
+  }
+
+  /**
+   * Check if this is a client error (4xx)
+   */
+  isClientError(): boolean {
+    return this.status >= 400 && this.status < 500
+  }
+
+  /**
+   * Check if this is a server error (5xx)
+   */
+  isServerError(): boolean {
+    return this.status >= 500 && this.status < 600
+  }
+}

web-app/package.json

@@ -21,8 +21,8 @@
     "@dnd-kit/core": "6.3.1",
     "@dnd-kit/modifiers": "9.0.0",
     "@dnd-kit/sortable": "10.0.0",
-    "@jan/extensions-web": "link:../extensions-web",
+    "@jan/extensions-web": "workspace:*",
-    "@janhq/core": "link:../core",
+    "@janhq/core": "workspace:*",
     "@radix-ui/react-accordion": "1.2.11",
     "@radix-ui/react-avatar": "1.1.10",
     "@radix-ui/react-dialog": "1.1.15",

web-app/src/constants/chat.ts

@@ -0,0 +1,6 @@
+/**
+ * Chat-related constants
+ */
+
+export const TEMPORARY_CHAT_ID = 'temporary-chat'
+export const TEMPORARY_CHAT_QUERY_ID = 'temporary-chat'

web-app/src/containers/HeaderPage.tsx

@@ -1,13 +1,40 @@
 import { useLeftPanel } from '@/hooks/useLeftPanel'
 import { cn } from '@/lib/utils'
-import { IconLayoutSidebar } from '@tabler/icons-react'
+import { IconLayoutSidebar, IconMessage, IconMessageFilled } from '@tabler/icons-react'
 import { ReactNode } from '@tanstack/react-router'
+import { useRouter } from '@tanstack/react-router'
+import { route } from '@/constants/routes'
+import { PlatformFeatures } from '@/lib/platform/const'
+import { PlatformFeature } from '@/lib/platform/types'
+import { TEMPORARY_CHAT_QUERY_ID } from '@/constants/chat'
 
 type HeaderPageProps = {
   children?: ReactNode
 }
 const HeaderPage = ({ children }: HeaderPageProps) => {
   const { open, setLeftPanel } = useLeftPanel()
+  const router = useRouter()
+  const currentPath = router.state.location.pathname
+
+  const isHomePage = currentPath === route.home
+
+  // Parse temporary chat flag from URL search params directly to avoid invariant errors
+  const searchString = window.location.search
+  const urlSearchParams = new URLSearchParams(searchString)
+  const isTemporaryChat = isHomePage && urlSearchParams.get(TEMPORARY_CHAT_QUERY_ID) === 'true'
+
+  const handleChatToggle = () => {
+    console.log('Chat toggle clicked!', { isTemporaryChat, isHomePage, currentPath })
+    if (isHomePage) {
+      if (isTemporaryChat) {
+        console.log('Switching to regular chat')
+        router.navigate({ to: route.home, search: {} })
+      } else {
+        console.log('Switching to temporary chat')
+        router.navigate({ to: route.home, search: { [TEMPORARY_CHAT_QUERY_ID]: true } })
+      }
+    }
+  }
 
   return (
     <div
@@ -30,6 +57,29 @@ const HeaderPage = ({ children }: HeaderPageProps) => {
           </button>
         )}
         {children}
+
+        {/* Temporary Chat Toggle - Only show on home page if feature is enabled */}
+        {PlatformFeatures[PlatformFeature.TEMPORARY_CHAT] && isHomePage && (
+          <div className="ml-auto">
+            <button
+              className="size-8 cursor-pointer flex items-center justify-center rounded hover:bg-main-view-fg/10 transition-all duration-200 ease-in-out relative z-20"
+              onClick={handleChatToggle}
+              title={isTemporaryChat ? 'Switch to Regular Chat' : 'Start Temporary Chat'}
+            >
+              {isTemporaryChat ? (
+                <IconMessageFilled
+                  size={18}
+                  className="text-main-view-fg"
+                />
+              ) : (
+                <IconMessage
+                  size={18}
+                  className="text-main-view-fg"
+                />
+              )}
+            </button>
+          </div>
+        )}
       </div>
     </div>
   )

web-app/src/hooks/useChat.ts

@@ -33,6 +33,7 @@ import {
 } from '@/utils/reasoning'
 import { useAssistant } from './useAssistant'
 import { useShallow } from 'zustand/shallow'
+import { TEMPORARY_CHAT_QUERY_ID, TEMPORARY_CHAT_ID } from '@/constants/chat'
 
 export const useChat = () => {
   const [
@@ -80,12 +81,21 @@ export const useChat = () => {
 
   const getMessages = useMessages((state) => state.getMessages)
   const addMessage = useMessages((state) => state.addMessage)
+  const setMessages = useMessages((state) => state.setMessages)
   const setModelLoadError = useModelLoad((state) => state.setModelLoadError)
   const router = useRouter()
 
   const getCurrentThread = useCallback(async () => {
     let currentThread = retrieveThread()
 
+    // Check if we're in temporary chat mode
+    const isTemporaryMode = window.location.search.includes(`${TEMPORARY_CHAT_QUERY_ID}=true`)
+
+    // Clear messages for existing temporary thread on reload to ensure fresh start
+    if (isTemporaryMode && currentThread?.id === TEMPORARY_CHAT_ID) {
+      setMessages(TEMPORARY_CHAT_ID, [])
+    }
+
     if (!currentThread) {
       // Get prompt directly from store when needed
       const currentPrompt = usePrompt.getState().prompt
@@ -93,14 +103,28 @@ export const useChat = () => {
       const assistants = useAssistant.getState().assistants
       const selectedModel = useModelProvider.getState().selectedModel
       const selectedProvider = useModelProvider.getState().selectedProvider
+
       currentThread = await createThread(
         {
           id: selectedModel?.id ?? defaultModel(selectedProvider),
           provider: selectedProvider,
         },
-        currentPrompt,
+        isTemporaryMode ? 'Temporary Chat' : currentPrompt,
-        assistants.find((a) => a.id === currentAssistant?.id) || assistants[0]
+        assistants.find((a) => a.id === currentAssistant?.id) || assistants[0],
+        undefined, // no project metadata
+        isTemporaryMode // pass temporary flag
       )
+
+      // Clear messages for temporary chat to ensure fresh start on reload
+      if (isTemporaryMode && currentThread?.id === TEMPORARY_CHAT_ID) {
+        setMessages(TEMPORARY_CHAT_ID, [])
+      }
+
+      // Set flag for temporary chat navigation
+      if (currentThread.id === TEMPORARY_CHAT_ID) {
+        sessionStorage.setItem('temp-chat-nav', 'true')
+      }
+
       router.navigate({
         to: route.threadsDetail,
         params: { threadId: currentThread.id },

web-app/src/hooks/useThreads.ts

@@ -2,6 +2,7 @@ import { create } from 'zustand'
 import { ulid } from 'ulidx'
 import { getServiceHub } from '@/hooks/useServiceHub'
 import { Fzf } from 'fzf'
+import { TEMPORARY_CHAT_ID } from '@/constants/chat'
 
 type ThreadState = {
   threads: Record<string, Thread>
@@ -21,7 +22,8 @@ type ThreadState = {
     model: ThreadModel,
     title?: string,
     assistant?: Assistant,
-    projectMetadata?: { id: string; name: string; updated_at: number }
+    projectMetadata?: { id: string; name: string; updated_at: number },
+    isTemporary?: boolean
   ) => Promise<Thread>
   updateCurrentThreadModel: (model: ThreadModel) => void
   getFilteredThreads: (searchTerm: string) => Thread[]
@@ -61,9 +63,12 @@ export const useThreads = create<ThreadState>()((set, get) => ({
       },
       {} as Record<string, Thread>
     )
+    // Filter out temporary chat for search index
+    const filteredForSearch = Object.values(threadMap).filter(t => t.id !== TEMPORARY_CHAT_ID)
+
     set({
       threads: threadMap,
-      searchIndex: new Fzf<Thread[]>(Object.values(threadMap), {
+      searchIndex: new Fzf<Thread[]>(filteredForSearch, {
         selector: (item: Thread) => item.title,
       }),
     })
@@ -71,15 +76,18 @@ export const useThreads = create<ThreadState>()((set, get) => ({
   getFilteredThreads: (searchTerm: string) => {
     const { threads, searchIndex } = get()
 
+    // Filter out temporary chat from all operations
+    const filteredThreadsValues = Object.values(threads).filter(t => t.id !== TEMPORARY_CHAT_ID)
+
     // If no search term, return all threads
     if (!searchTerm) {
       // return all threads
-      return Object.values(threads)
+      return filteredThreadsValues
     }
 
     let currentIndex = searchIndex
     if (!currentIndex?.find) {
-      currentIndex = new Fzf<Thread[]>(Object.values(threads), {
+      currentIndex = new Fzf<Thread[]>(filteredThreadsValues, {
         selector: (item: Thread) => item.title,
       })
       set({ searchIndex: currentIndex })
@@ -125,7 +133,7 @@ export const useThreads = create<ThreadState>()((set, get) => ({
       getServiceHub().threads().deleteThread(threadId)
       return {
         threads: remainingThreads,
-        searchIndex: new Fzf<Thread[]>(Object.values(remainingThreads), {
+        searchIndex: new Fzf<Thread[]>(Object.values(remainingThreads).filter(t => t.id !== TEMPORARY_CHAT_ID), {
           selector: (item: Thread) => item.title,
         }),
       }
@@ -165,7 +173,7 @@ export const useThreads = create<ThreadState>()((set, get) => ({
 
       return {
         threads: remainingThreads,
-        searchIndex: new Fzf<Thread[]>(Object.values(remainingThreads), {
+        searchIndex: new Fzf<Thread[]>(Object.values(remainingThreads).filter(t => t.id !== TEMPORARY_CHAT_ID), {
           selector: (item: Thread) => item.title,
         }),
       }
@@ -218,18 +226,24 @@ export const useThreads = create<ThreadState>()((set, get) => ({
   setCurrentThreadId: (threadId) => {
     if (threadId !== get().currentThreadId) set({ currentThreadId: threadId })
   },
-  createThread: async (model, title, assistant, projectMetadata) => {
+  createThread: async (model, title, assistant, projectMetadata, isTemporary) => {
     const newThread: Thread = {
-      id: ulid(),
+      id: isTemporary ? TEMPORARY_CHAT_ID : ulid(),
-      title: title ?? 'New Thread',
+      title: title ?? (isTemporary ? 'Temporary Chat' : 'New Thread'),
       model,
       updated: Date.now() / 1000,
       assistants: assistant ? [assistant] : [],
-      ...(projectMetadata && {
+      ...(projectMetadata && !isTemporary && {
         metadata: {
           project: projectMetadata,
         },
       }),
+      ...(isTemporary && {
+        metadata: {
+          isTemporary: true,
+          ...(projectMetadata && { project: projectMetadata }),
+        },
+      }),
     }
     return await getServiceHub()
       .threads()
@@ -307,7 +321,7 @@ export const useThreads = create<ThreadState>()((set, get) => ({
       const newThreads = { ...state.threads, [threadId]: updatedThread }
       return {
         threads: newThreads,
-        searchIndex: new Fzf<Thread[]>(Object.values(newThreads), {
+        searchIndex: new Fzf<Thread[]>(Object.values(newThreads).filter(t => t.id !== TEMPORARY_CHAT_ID), {
           selector: (item: Thread) => item.title,
         }),
       }
@@ -337,7 +351,7 @@ export const useThreads = create<ThreadState>()((set, get) => ({
 
       return {
         threads: updatedThreads,
-        searchIndex: new Fzf<Thread[]>(Object.values(updatedThreads), {
+        searchIndex: new Fzf<Thread[]>(Object.values(updatedThreads).filter(t => t.id !== TEMPORARY_CHAT_ID), {
           selector: (item: Thread) => item.title,
         }),
       }
@@ -359,7 +373,7 @@ export const useThreads = create<ThreadState>()((set, get) => ({
       const newThreads = { ...state.threads, [threadId]: updatedThread }
       return {
         threads: newThreads,
-        searchIndex: new Fzf<Thread[]>(Object.values(newThreads), {
+        searchIndex: new Fzf<Thread[]>(Object.values(newThreads).filter(t => t.id !== TEMPORARY_CHAT_ID), {
           selector: (item: Thread) => item.title,
         }),
       }

web-app/src/lib/platform/const.ts

@@ -64,4 +64,7 @@ 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
+  [PlatformFeature.TEMPORARY_CHAT]: !isPlatformTauri(),
 }

web-app/src/lib/platform/types.ts

@@ -66,4 +66,7 @@ export enum PlatformFeature {
 
   // First message persisted thread - web-only feature for storing first user message locally during thread creation
   FIRST_MESSAGE_PERSISTED_THREAD = 'firstMessagePersistedThread',
+
+  // Temporary chat mode - web-only feature for ephemeral conversations like ChatGPT
+  TEMPORARY_CHAT = 'temporaryChat',
 }

web-app/src/locales/en/chat.json

@@ -1,6 +1,8 @@
 {
   "welcome": "Hi, how are you?",
   "description": "How can I help you today?",
+  "temporaryChat": "Temporary Chat",
+  "temporaryChatDescription": "Start a temporary conversation that won't be saved to your chat history.",
   "status": {
     "empty": "No Chats Found"
   },

web-app/src/locales/en/common.json

@@ -124,6 +124,10 @@
   "error": "Error",
   "success": "Success",
   "warning": "Warning",
+  "conversationNotAvailable": "Conversation not available",
+  "conversationNotAvailableDescription": "The conversation you are trying to access is not available or has been deleted.",
+  "temporaryChat": "Temporary Chat",
+  "temporaryChatTooltip": "Temporary chat won't appear in your history",
   "noResultsFoundDesc": "We couldn't find any chats matching your search. Try a different keyword.",
   "searchModels": "Search models...",
   "searchStyles": "Search styles...",

web-app/src/routes/index.tsx

@@ -13,18 +13,29 @@ type SearchParams = {
     id: string
     provider: string
   }
+  'temporary-chat'?: boolean
 }
 import DropdownAssistant from '@/containers/DropdownAssistant'
 import { useEffect } from 'react'
 import { useThreads } from '@/hooks/useThreads'
 import { PlatformFeatures } from '@/lib/platform/const'
 import { PlatformFeature } from '@/lib/platform/types'
+import { TEMPORARY_CHAT_QUERY_ID } from '@/constants/chat'
 
 export const Route = createFileRoute(route.home as any)({
   component: Index,
-  validateSearch: (search: Record<string, unknown>): SearchParams => ({
+  validateSearch: (search: Record<string, unknown>): SearchParams => {
-    model: search.model as SearchParams['model'],
+    const result: SearchParams = {
-  }),
+      model: search.model as SearchParams['model'],
+    }
+
+    // Only include temporary-chat if it's explicitly true
+    if (search[TEMPORARY_CHAT_QUERY_ID] === 'true' || search[TEMPORARY_CHAT_QUERY_ID] === true) {
+      result['temporary-chat'] = true
+    }
+
+    return result
+  },
 })
 
 function Index() {
@@ -32,6 +43,7 @@ function Index() {
   const { providers } = useModelProvider()
   const search = useSearch({ from: route.home as any })
   const selectedModel = search.model
+  const isTemporaryChat = search['temporary-chat']
   const { setCurrentThreadId } = useThreads()
 
   // Conditional to check if there are any valid providers
@@ -60,10 +72,10 @@ function Index() {
         <div className="w-full md:w-4/6 mx-auto">
           <div className="mb-8 text-center">
             <h1 className="font-editorialnew text-main-view-fg text-4xl">
-              {t('chat:welcome')}
+              {isTemporaryChat ? t('chat:temporaryChat') : t('chat:welcome')}
             </h1>
             <p className="text-main-view-fg/70 text-lg mt-2">
-              {t('chat:description')}
+              {isTemporaryChat ? t('chat:temporaryChatDescription') : t('chat:description')}
             </p>
           </div>
           <div className="flex-1 shrink-0">

web-app/src/routes/threads/$threadId.tsx

@@ -1,7 +1,9 @@
 import { useEffect, useMemo, useRef } from 'react'
-import { createFileRoute, useParams } from '@tanstack/react-router'
+import { createFileRoute, useParams, redirect, useNavigate } from '@tanstack/react-router'
 import cloneDeep from 'lodash.clonedeep'
 import { cn } from '@/lib/utils'
+import { toast } from 'sonner'
+import { useTranslation } from '@/i18n/react-i18next-compat'
 
 import HeaderPage from '@/containers/HeaderPage'
 import { useThreads } from '@/hooks/useThreads'
@@ -21,16 +23,63 @@ import { PlatformFeatures } from '@/lib/platform/const'
 import { PlatformFeature } from '@/lib/platform/types'
 import ScrollToBottom from '@/containers/ScrollToBottom'
 import { PromptProgress } from '@/components/PromptProgress'
+import { TEMPORARY_CHAT_ID, TEMPORARY_CHAT_QUERY_ID } from '@/constants/chat'
 import { useThreadScrolling } from '@/hooks/useThreadScrolling'
+import { IconInfoCircle } from '@tabler/icons-react'
+import { Tooltip, TooltipContent, TooltipTrigger } from '@/components/ui/tooltip'
+
+const CONVERSATION_NOT_FOUND_EVENT = 'conversation-not-found'
+
+const TemporaryChatIndicator = ({ t }: { t: (key: string) => string }) => {
+  return (
+    <div className="flex items-center gap-1.5 px-3 py-1 rounded-md bg-main-view-fg/5 text-main-view-fg/70 text-sm">
+      <span>{t('common:temporaryChat')}</span>
+      <Tooltip>
+        <TooltipTrigger asChild>
+          <div className="relative z-20">
+            <IconInfoCircle
+              size={14}
+              className="text-main-view-fg/50 hover:text-main-view-fg/70 transition-colors cursor-pointer"
+            />
+          </div>
+        </TooltipTrigger>
+        <TooltipContent className="z-[9999]">
+          <p>{t('common:temporaryChatTooltip')}</p>
+        </TooltipContent>
+      </Tooltip>
+    </div>
+  )
+}
 
 // as route.threadsDetail
 export const Route = createFileRoute('/threads/$threadId')({
+  beforeLoad: ({ params }) => {
+    // Check if this is the temporary chat being accessed directly
+    if (params.threadId === TEMPORARY_CHAT_ID) {
+      // Check if we have the navigation flag in sessionStorage
+      const hasNavigationFlag = sessionStorage.getItem('temp-chat-nav')
+
+      if (!hasNavigationFlag) {
+        // Direct access - redirect to home with query parameter
+        throw redirect({
+          to: '/',
+          search: { [TEMPORARY_CHAT_QUERY_ID]: true },
+          replace: true,
+        })
+      }
+
+      // Clear the flag immediately after checking
+      sessionStorage.removeItem('temp-chat-nav')
+    }
+  },
   component: ThreadDetail,
 })
 
 function ThreadDetail() {
   const serviceHub = useServiceHub()
   const { threadId } = useParams({ from: Route.id })
+  const navigate = useNavigate()
+  const { t } = useTranslation()
   const setCurrentThreadId = useThreads((state) => state.setCurrentThreadId)
   const setCurrentAssistant = useAssistant((state) => state.setCurrentAssistant)
   const assistants = useAssistant((state) => state.assistants)
@@ -49,9 +98,33 @@ function ThreadDetail() {
   const thread = useThreads(useShallow((state) => state.threads[threadId]))
   const scrollContainerRef = useRef<HTMLDivElement>(null)
 
+
   // Get padding height for ChatGPT-style message positioning
   const { paddingHeight } = useThreadScrolling(threadId, scrollContainerRef)
 
+  // Listen for conversation not found events
+  useEffect(() => {
+    const handleConversationNotFound = (event: CustomEvent) => {
+      const { threadId: notFoundThreadId } = event.detail
+      if (notFoundThreadId === threadId) {
+        // Skip error handling for temporary chat - it's expected to not exist on server
+        if (threadId === TEMPORARY_CHAT_ID) {
+          return
+        }
+
+        toast.error(t('common:conversationNotAvailable'), {
+          description: t('common:conversationNotAvailableDescription')
+        })
+        navigate({ to: '/', replace: true })
+      }
+    }
+
+    window.addEventListener(CONVERSATION_NOT_FOUND_EVENT, handleConversationNotFound as EventListener)
+    return () => {
+      window.removeEventListener(CONVERSATION_NOT_FOUND_EVENT, handleConversationNotFound as EventListener)
+    }
+  }, [threadId, navigate])
+
   useEffect(() => {
     setCurrentThreadId(threadId)
     const assistant = assistants.find(
@@ -137,9 +210,15 @@ function ThreadDetail() {
     <div className="flex flex-col h-full">
       <HeaderPage>
         <div className="flex items-center justify-between w-full pr-2">
-          {PlatformFeatures[PlatformFeature.ASSISTANTS] && (
+          <div>
-            <DropdownAssistant />
+            {PlatformFeatures[PlatformFeature.ASSISTANTS] && (
-          )}
+              <DropdownAssistant />
+            )}
+          </div>
+          <div className="flex-1 flex justify-center">
+            {threadId === TEMPORARY_CHAT_ID && <TemporaryChatIndicator t={t} />}
+          </div>
+          <div></div>
         </div>
       </HeaderPage>
       <div className="flex flex-col h-[calc(100%-40px)]">

web-app/src/services/messages/default.ts

@@ -8,10 +8,16 @@ import {
   ExtensionTypeEnum,
   ThreadMessage,
 } from '@janhq/core'
+import { TEMPORARY_CHAT_ID } from '@/constants/chat'
 import type { MessagesService } from './types'
 
 export class DefaultMessagesService implements MessagesService {
   async fetchMessages(threadId: string): Promise<ThreadMessage[]> {
+    // Don't fetch messages from server for temporary chat - it's local only
+    if (threadId === TEMPORARY_CHAT_ID) {
+      return []
+    }
+
     return (
       ExtensionManager.getInstance()
         .get<ConversationalExtension>(ExtensionTypeEnum.Conversational)
@@ -21,6 +27,11 @@ export class DefaultMessagesService implements MessagesService {
   }
 
   async createMessage(message: ThreadMessage): Promise<ThreadMessage> {
+    // Don't create messages on server for temporary chat - it's local only
+    if (message.thread_id === TEMPORARY_CHAT_ID) {
+      return message
+    }
+
     return (
       ExtensionManager.getInstance()
         .get<ConversationalExtension>(ExtensionTypeEnum.Conversational)
@@ -30,6 +41,11 @@ export class DefaultMessagesService implements MessagesService {
   }
 
   async deleteMessage(threadId: string, messageId: string): Promise<void> {
+    // Don't delete messages on server for temporary chat - it's local only
+    if (threadId === TEMPORARY_CHAT_ID) {
+      return
+    }
+
     await ExtensionManager.getInstance()
       .get<ConversationalExtension>(ExtensionTypeEnum.Conversational)
       ?.deleteMessage(threadId, messageId)

web-app/src/services/threads/default.ts

@@ -6,6 +6,7 @@ import { defaultAssistant } from '@/hooks/useAssistant'
 import { ExtensionManager } from '@/lib/extension'
 import { ConversationalExtension, ExtensionTypeEnum } from '@janhq/core'
 import type { ThreadsService } from './types'
+import { TEMPORARY_CHAT_ID } from '@/constants/chat'
 
 export class DefaultThreadsService implements ThreadsService {
   async fetchThreads(): Promise<Thread[]> {
@@ -16,7 +17,10 @@ export class DefaultThreadsService implements ThreadsService {
         .then((threads) => {
           if (!Array.isArray(threads)) return []
 
-          return threads.map((e) => {
+          // Filter out temporary threads from the list
+          const filteredThreads = threads.filter((e) => e.id !== TEMPORARY_CHAT_ID)
+
+          return filteredThreads.map((e) => {
             return {
               ...e,
               updated:
@@ -47,6 +51,11 @@ export class DefaultThreadsService implements ThreadsService {
   }
 
   async createThread(thread: Thread): Promise<Thread> {
+    // For temporary threads, bypass the conversational extension (in-memory only)
+    if (thread.id === TEMPORARY_CHAT_ID) {
+      return thread
+    }
+
     return (
       ExtensionManager.getInstance()
         .get<ConversationalExtension>(ExtensionTypeEnum.Conversational)
@@ -82,6 +91,11 @@ export class DefaultThreadsService implements ThreadsService {
   }
 
   async updateThread(thread: Thread): Promise<void> {
+    // For temporary threads, skip updating via conversational extension
+    if (thread.id === TEMPORARY_CHAT_ID) {
+      return
+    }
+
     await ExtensionManager.getInstance()
       .get<ConversationalExtension>(ExtensionTypeEnum.Conversational)
       ?.modifyThread({
@@ -118,6 +132,11 @@ export class DefaultThreadsService implements ThreadsService {
   }
 
   async deleteThread(threadId: string): Promise<void> {
+    // For temporary threads, skip deleting via conversational extension
+    if (threadId === TEMPORARY_CHAT_ID) {
+      return
+    }
+
     await ExtensionManager.getInstance()
       .get<ConversationalExtension>(ExtensionTypeEnum.Conversational)
       ?.deleteThread(threadId)