feat: implement basic web app

frontend/package.json

@@ -16,6 +16,8 @@
     "typecheck": "tsc --noEmit"
   },
   "dependencies": {
+    "@langchain/core": "^1.1.15",
+    "@langchain/langgraph-sdk": "^1.5.3",
     "@radix-ui/react-collapsible": "^1.1.12",
     "@radix-ui/react-dialog": "^1.1.15",
     "@radix-ui/react-dropdown-menu": "^2.1.16",
@@ -28,25 +30,31 @@
     "@radix-ui/react-tooltip": "^1.2.8",
     "@radix-ui/react-use-controllable-state": "^1.2.2",
     "@t3-oss/env-nextjs": "^0.12.0",
+    "@tanstack/react-query": "^5.90.17",
+    "@types/hast": "^3.0.4",
     "@xyflow/react": "^12.10.0",
     "ai": "^6.0.33",
+    "best-effort-json-parser": "^1.2.1",
     "better-auth": "^1.3",
     "class-variance-authority": "^0.7.1",
     "clsx": "^2.1.1",
     "cmdk": "^1.1.1",
     "embla-carousel-react": "^8.6.0",
+    "hast": "^1.0.0",
     "lucide-react": "^0.562.0",
     "motion": "^12.26.2",
     "nanoid": "^5.1.6",
-    "next": "^16.1.1",
+    "next": "^15.2.8",
     "next-themes": "^0.4.6",
     "react": "^19.0.0",
     "react-dom": "^19.0.0",
     "shiki": "^3.21.0",
-    "streamdown": "^2.0.1",
+    "streamdown": "1.5.1",
     "tailwind-merge": "^3.4.0",
     "tokenlens": "^1.3.1",
+    "unist-util-visit": "^5.0.0",
     "use-stick-to-bottom": "^1.1.1",
+    "uuid": "^13.0.0",
     "zod": "^3.24.2"
   },
   "devDependencies": {

frontend/src/app/api/langgraph/[...path]/route.ts

@@ -0,0 +1,98 @@
+import { type NextRequest } from "next/server";
+
+export const runtime = "nodejs";
+
+export async function GET(
+  request: NextRequest,
+  { params }: { params: Promise<{ path: string[] }> },
+) {
+  return handleProxy(request, (await params).path);
+}
+
+export async function POST(
+  request: NextRequest,
+  { params }: { params: Promise<{ path: string[] }> },
+) {
+  return handleProxy(request, (await params).path);
+}
+
+export async function PUT(
+  request: NextRequest,
+  { params }: { params: Promise<{ path: string[] }> },
+) {
+  return handleProxy(request, (await params).path);
+}
+
+export async function DELETE(
+  request: NextRequest,
+  { params }: { params: Promise<{ path: string[] }> },
+) {
+  return handleProxy(request, (await params).path);
+}
+
+async function handleProxy(request: NextRequest, pathSegments: string[]) {
+  const targetUrl = `http://localhost:2024/${pathSegments.join("/")}`;
+
+  // Preserve query parameters
+  const searchParams = request.nextUrl.searchParams.toString();
+  const fullUrl = searchParams ? `${targetUrl}?${searchParams}` : targetUrl;
+
+  // Prepare headers
+  const headers = new Headers();
+  request.headers.forEach((value, key) => {
+    // Skip Next.js specific headers
+    if (!key.startsWith("x-") && key !== "host" && key !== "connection") {
+      headers.set(key, value);
+    }
+  });
+
+  // Prepare fetch options
+  const fetchOptions: RequestInit = {
+    method: request.method,
+    headers,
+  };
+
+  // Add body for non-GET requests
+  if (request.method !== "GET" && request.method !== "HEAD") {
+    fetchOptions.body = await request.text();
+  }
+
+  try {
+    const response = await fetch(fullUrl, fetchOptions);
+
+    // Check if response is SSE
+    const contentType = response.headers.get("content-type");
+    const isSSE = contentType?.includes("text/event-stream");
+
+    if (isSSE && response.body) {
+      // Handle SSE streaming
+      return new Response(response.body, {
+        status: response.status,
+        statusText: response.statusText,
+        headers: {
+          "Content-Type": "text/event-stream",
+          "Cache-Control": "no-cache",
+          Connection: "keep-alive",
+        },
+      });
+    }
+
+    // Handle regular responses
+    const responseHeaders = new Headers();
+    response.headers.forEach((value, key) => {
+      responseHeaders.set(key, value);
+    });
+
+    return new Response(response.body, {
+      status: response.status,
+      statusText: response.statusText,
+      headers: responseHeaders,
+    });
+  } catch (error) {
+    console.error("Proxy error:", error);
+    return new Response(JSON.stringify({ error: "Proxy request failed" }), {
+      status: 502,
+      headers: { "Content-Type": "application/json" },
+    });
+  }
+}

frontend/src/app/layout.tsx

@@ -3,8 +3,10 @@ import "@/styles/globals.css";
 import { type Metadata } from "next";
 import { Geist } from "next/font/google";
 
+import { ThemeProvider } from "@/components/theme-provider";
+
 export const metadata: Metadata = {
-  title: "DeerFlow",
+  title: "Welcome to DeerFlow",
   description: "A LangChain-based framework for building super agents.",
   icons: [{ rel: "icon", url: "/favicon.ico" }],
 };
@@ -18,8 +20,21 @@ export default function RootLayout({
   children,
 }: Readonly<{ children: React.ReactNode }>) {
   return (
-    <html lang="en" className={`${geist.variable}`}>
-      <body>{children}</body>
+    <html
+      className={geist.variable}
+      suppressContentEditableWarning
+      suppressHydrationWarning
+    >
+      <body>
+        <ThemeProvider
+          attribute="class"
+          defaultTheme="dark"
+          enableSystem
+          disableTransitionOnChange
+        >
+          {children}
+        </ThemeProvider>
+      </body>
     </html>
   );
 }

frontend/src/app/page.tsx

@@ -1,7 +1,5 @@
 export default async function LandingPage() {
   return (
-    <main className="flex min-h-screen flex-col items-center justify-center">
-      Welcome to DeerFlow 2
-    </main>
+    <main className="flex min-h-screen flex-col">DeerFlow Landing Page</main>
   );
 }

frontend/src/app/workspace/chats/[thread_id]/page.tsx

@@ -0,0 +1,115 @@
+"use client";
+
+import { type HumanMessage } from "@langchain/core/messages";
+import { useStream } from "@langchain/langgraph-sdk/react";
+import { useQueryClient } from "@tanstack/react-query";
+import { useParams, useRouter } from "next/navigation";
+import { useCallback, useEffect, useMemo, useState } from "react";
+
+import type { PromptInputMessage } from "@/components/ai-elements/prompt-input";
+import { BreadcrumbItem } from "@/components/ui/breadcrumb";
+import { InputBox } from "@/components/workspace/input-box";
+import { MessageList } from "@/components/workspace/message-list/message-list";
+import {
+  WorkspaceContainer,
+  WorkspaceBody,
+  WorkspaceHeader,
+  WorkspaceFooter,
+} from "@/components/workspace/workspace-container";
+import { getLangGraphClient } from "@/core/api";
+import type { MessageThread, MessageThreadState } from "@/core/thread";
+import { titleOfThread } from "@/core/thread/utils";
+import { uuid } from "@/core/utils/uuid";
+
+const langGraphClient = getLangGraphClient();
+
+export default function ChatPage() {
+  const router = useRouter();
+  const queryClient = useQueryClient();
+  const { thread_id: threadIdFromPath } = useParams<{ thread_id: string }>();
+  const isNewThread = useMemo(
+    () => threadIdFromPath === "new",
+    [threadIdFromPath],
+  );
+  const [threadId, setThreadId] = useState<string | null>(null);
+  useEffect(() => {
+    if (threadIdFromPath !== "new") {
+      setThreadId(threadIdFromPath);
+    } else {
+      setThreadId(uuid());
+    }
+  }, [threadIdFromPath]);
+  const thread = useStream<MessageThreadState>({
+    client: langGraphClient,
+    assistantId: "lead_agent",
+    threadId: !isNewThread ? threadId : undefined,
+    reconnectOnMount: true,
+    fetchStateHistory: true,
+    onFinish() {
+      void queryClient.invalidateQueries({ queryKey: ["threads", "search"] });
+    },
+  });
+  const handleSubmit = useCallback(
+    async (message: PromptInputMessage) => {
+      const text = message.text.trim();
+      if (isNewThread) {
+        router.replace(`/workspace/chats/${threadId}`);
+      }
+      await thread.submit(
+        {
+          messages: [
+            {
+              type: "human",
+              content: [
+                {
+                  type: "text",
+                  text,
+                },
+              ],
+            },
+          ] as HumanMessage[],
+        },
+        {
+          threadId: isNewThread ? threadId! : undefined,
+          streamSubgraphs: true,
+          streamResumable: true,
+          context: {
+            thread_id: threadId!,
+            model: "deepseek-v3.2",
+            thinking_enabled: true,
+          },
+        },
+      );
+      void queryClient.invalidateQueries({ queryKey: ["threads", "search"] });
+    },
+    [isNewThread, queryClient, router, thread, threadId],
+  );
+  const handleStop = useCallback(async () => {
+    await thread.stop();
+  }, [thread]);
+  return (
+    <WorkspaceContainer>
+      <WorkspaceHeader>
+        <BreadcrumbItem className="hidden md:block">
+          {isNewThread
+            ? "New"
+            : titleOfThread(thread as unknown as MessageThread)}
+        </BreadcrumbItem>
+      </WorkspaceHeader>
+      <WorkspaceBody>
+        <div className="flex size-full justify-center">
+          <MessageList className="size-full" thread={thread} />
+        </div>
+      </WorkspaceBody>
+      <WorkspaceFooter>
+        <InputBox
+          className="max-w-(--container-width-md)"
+          autoFocus={isNewThread}
+          status={thread.isLoading ? "streaming" : "ready"}
+          onSubmit={handleSubmit}
+          onStop={handleStop}
+        />
+      </WorkspaceFooter>
+    </WorkspaceContainer>
+  );
+}

frontend/src/app/workspace/chats/page.tsx

@@ -0,0 +1,18 @@
+"use client";
+
+import {
+  WorkspaceBody,
+  WorkspaceContainer,
+  WorkspaceHeader,
+} from "@/components/workspace/workspace-container";
+
+export default function ChatsPage() {
+  return (
+    <WorkspaceContainer>
+      <WorkspaceHeader></WorkspaceHeader>
+      <WorkspaceBody>
+        <div className="flex size-full justify-center"></div>
+      </WorkspaceBody>
+    </WorkspaceContainer>
+  );
+}

frontend/src/app/workspace/layout.tsx

@@ -0,0 +1,29 @@
+"use client";
+
+import { QueryClient, QueryClientProvider } from "@tanstack/react-query";
+
+import { SidebarInset, SidebarProvider } from "@/components/ui/sidebar";
+import { Overscroll } from "@/components/workspace/overscroll";
+import { WorkspaceSidebar } from "@/components/workspace/workspace-sidebar";
+
+const queryClient = new QueryClient();
+
+export default function WorkspaceLayout({
+  children,
+}: Readonly<{ children: React.ReactNode }>) {
+  return (
+    <QueryClientProvider client={queryClient}>
+      <SidebarProvider
+        style={
+          {
+            "--sidebar-width": "calc(var(--spacing) * 72)",
+          } as React.CSSProperties
+        }
+      >
+        <Overscroll behavior="none" overflow="hidden" />
+        <WorkspaceSidebar />
+        <SidebarInset>{children}</SidebarInset>
+      </SidebarProvider>
+    </QueryClientProvider>
+  );
+}

frontend/src/app/workspace/page.tsx

@@ -0,0 +1,5 @@
+import { redirect } from "next/navigation";
+
+export default function WorkspacePage() {
+  return redirect("/workspace/chats/new");
+}

frontend/src/app/workspace/threads/[thread_id]/page.tsx

@@ -0,0 +1,26 @@
+"use client";
+
+import { useStream } from "@langchain/langgraph-sdk/react";
+import { useParams } from "next/navigation";
+
+import { getLangGraphClient } from "@/core/api";
+import type { MessageThreadState } from "@/core/thread";
+
+const apiClient = getLangGraphClient();
+
+export default function TestPage() {
+  const { thread_id: threadId } = useParams<{ thread_id: string }>();
+  const thread = useStream<MessageThreadState>({
+    client: apiClient,
+    assistantId: "lead_agent",
+    threadId,
+    reconnectOnMount: true,
+    fetchStateHistory: true,
+  });
+  return (
+    <div className="p-4">
+      <div>{threadId}</div>
+      <div>{thread.isLoading ? "loading" : "not loading"}</div>
+    </div>
+  );
+}

frontend/src/components/ai-elements/chain-of-thought.tsx

@@ -23,14 +23,14 @@ type ChainOfThoughtContextValue = {
 };
 
 const ChainOfThoughtContext = createContext<ChainOfThoughtContextValue | null>(
-  null
+  null,
 );
 
 const useChainOfThought = () => {
   const context = useContext(ChainOfThoughtContext);
   if (!context) {
     throw new Error(
-      "ChainOfThought components must be used within ChainOfThought"
+      "ChainOfThought components must be used within ChainOfThought",
     );
   }
   return context;
@@ -59,7 +59,7 @@ export const ChainOfThought = memo(
 
     const chainOfThoughtContext = useMemo(
       () => ({ isOpen, setIsOpen }),
-      [isOpen, setIsOpen]
+      [isOpen, setIsOpen],
     );
 
     return (
@@ -72,40 +72,42 @@ export const ChainOfThought = memo(
         </div>
       </ChainOfThoughtContext.Provider>
     );
-  }
+  },
 );
 
 export type ChainOfThoughtHeaderProps = ComponentProps<
   typeof CollapsibleTrigger
->;
+> & {
+  icon?: React.ReactElement;
+};
 
 export const ChainOfThoughtHeader = memo(
-  ({ className, children, ...props }: ChainOfThoughtHeaderProps) => {
+  ({ className, children, icon, ...props }: ChainOfThoughtHeaderProps) => {
     const { isOpen, setIsOpen } = useChainOfThought();
 
     return (
       <Collapsible onOpenChange={setIsOpen} open={isOpen}>
         <CollapsibleTrigger
           className={cn(
-            "flex w-full items-center gap-2 text-muted-foreground text-sm transition-colors hover:text-foreground",
-            className
+            "text-muted-foreground hover:text-foreground flex w-full items-center gap-2 text-sm transition-colors",
+            className,
           )}
           {...props}
         >
-          <BrainIcon className="size-4" />
+          {icon ?? <BrainIcon className="size-4" />}
           <span className="flex-1 text-left">
             {children ?? "Chain of Thought"}
           </span>
           <ChevronDownIcon
             className={cn(
               "size-4 transition-transform",
-              isOpen ? "rotate-180" : "rotate-0"
+              isOpen ? "rotate-180" : "rotate-0",
             )}
           />
         </CollapsibleTrigger>
       </Collapsible>
     );
-  }
+  },
 );
 
 export type ChainOfThoughtStepProps = ComponentProps<"div"> & {
@@ -137,13 +139,13 @@ export const ChainOfThoughtStep = memo(
           "flex gap-2 text-sm",
           statusStyles[status],
           "fade-in-0 slide-in-from-top-2 animate-in",
-          className
+          className,
         )}
         {...props}
       >
         <div className="relative mt-0.5">
           <Icon className="size-4" />
-          <div className="-mx-px absolute top-7 bottom-0 left-1/2 w-px bg-border" />
+          <div className="bg-border absolute top-7 bottom-0 left-1/2 -mx-px w-px" />
         </div>
         <div className="flex-1 space-y-2 overflow-hidden">
           <div>{label}</div>
@@ -154,7 +156,7 @@ export const ChainOfThoughtStep = memo(
         </div>
       </div>
     );
-  }
+  },
 );
 
 export type ChainOfThoughtSearchResultsProps = ComponentProps<"div">;
@@ -165,7 +167,7 @@ export const ChainOfThoughtSearchResults = memo(
       className={cn("flex flex-wrap items-center gap-2", className)}
       {...props}
     />
-  )
+  ),
 );
 
 export type ChainOfThoughtSearchResultProps = ComponentProps<typeof Badge>;
@@ -173,13 +175,13 @@ export type ChainOfThoughtSearchResultProps = ComponentProps<typeof Badge>;
 export const ChainOfThoughtSearchResult = memo(
   ({ className, children, ...props }: ChainOfThoughtSearchResultProps) => (
     <Badge
-      className={cn("gap-1 px-2 py-0.5 font-normal text-xs", className)}
+      className={cn("gap-1 px-2 py-0.5 text-xs font-normal", className)}
       variant="secondary"
       {...props}
     >
       {children}
     </Badge>
-  )
+  ),
 );
 
 export type ChainOfThoughtContentProps = ComponentProps<
@@ -195,8 +197,8 @@ export const ChainOfThoughtContent = memo(
         <CollapsibleContent
           className={cn(
             "mt-2 space-y-3",
-            "data-[state=closed]:fade-out-0 data-[state=closed]:slide-out-to-top-2 data-[state=open]:slide-in-from-top-2 text-popover-foreground outline-none data-[state=closed]:animate-out data-[state=open]:animate-in",
-            className
+            "data-[state=closed]:fade-out-0 data-[state=closed]:slide-out-to-top-2 data-[state=open]:slide-in-from-top-2 text-popover-foreground data-[state=closed]:animate-out data-[state=open]:animate-in outline-none",
+            className,
           )}
           {...props}
         >
@@ -204,7 +206,7 @@ export const ChainOfThoughtContent = memo(
         </CollapsibleContent>
       </Collapsible>
     );
-  }
+  },
 );
 
 export type ChainOfThoughtImageProps = ComponentProps<"div"> & {
@@ -214,12 +216,12 @@ export type ChainOfThoughtImageProps = ComponentProps<"div"> & {
 export const ChainOfThoughtImage = memo(
   ({ className, children, caption, ...props }: ChainOfThoughtImageProps) => (
     <div className={cn("mt-2 space-y-2", className)} {...props}>
-      <div className="relative flex max-h-[22rem] items-center justify-center overflow-hidden rounded-lg bg-muted p-3">
+      <div className="bg-muted relative flex max-h-[22rem] items-center justify-center overflow-hidden rounded-lg p-3">
         {children}
       </div>
       {caption && <p className="text-muted-foreground text-xs">{caption}</p>}
     </div>
-  )
+  ),
 );
 
 ChainOfThought.displayName = "ChainOfThought";

frontend/src/components/ai-elements/message.tsx

@@ -1,10 +1,7 @@
 "use client";
 
 import { Button } from "@/components/ui/button";
-import {
-  ButtonGroup,
-  ButtonGroupText,
-} from "@/components/ui/button-group";
+import { ButtonGroup, ButtonGroupText } from "@/components/ui/button-group";
 import {
   Tooltip,
   TooltipContent,
@@ -30,9 +27,9 @@ export type MessageProps = HTMLAttributes<HTMLDivElement> & {
 export const Message = ({ className, from, ...props }: MessageProps) => (
   <div
     className={cn(
-      "group flex w-full max-w-[95%] flex-col gap-2",
+      "group flex w-full flex-col gap-2",
       from === "user" ? "is-user ml-auto justify-end" : "is-assistant",
-      className
+      className,
     )}
     {...props}
   />
@@ -47,10 +44,10 @@ export const MessageContent = ({
 }: MessageContentProps) => (
   <div
     className={cn(
-      "is-user:dark flex w-fit max-w-full min-w-0 flex-col gap-2 overflow-hidden text-sm",
-      "group-[.is-user]:ml-auto group-[.is-user]:rounded-lg group-[.is-user]:bg-secondary group-[.is-user]:px-4 group-[.is-user]:py-3 group-[.is-user]:text-foreground",
+      "is-user:dark flex w-fit max-w-full min-w-0 flex-col gap-2 overflow-hidden",
+      "group-[.is-user]:bg-secondary group-[.is-user]:text-foreground group-[.is-user]:ml-auto group-[.is-user]:rounded-lg group-[.is-user]:px-4 group-[.is-user]:py-3",
       "group-[.is-assistant]:text-foreground",
-      className
+      className,
     )}
     {...props}
   >
@@ -116,7 +113,7 @@ type MessageBranchContextType = {
 };
 
 const MessageBranchContext = createContext<MessageBranchContextType | null>(
-  null
+  null,
 );
 
 const useMessageBranch = () => {
@@ -124,7 +121,7 @@ const useMessageBranch = () => {
 
   if (!context) {
     throw new Error(
-      "MessageBranch components must be used within MessageBranch"
+      "MessageBranch components must be used within MessageBranch",
     );
   }
 
@@ -201,7 +198,7 @@ export const MessageBranchContent = ({
     <div
       className={cn(
         "grid gap-2 overflow-hidden [&>div]:pb-0",
-        index === currentBranch ? "block" : "hidden"
+        index === currentBranch ? "block" : "hidden",
       )}
       key={branch.key}
       {...props}
@@ -294,8 +291,8 @@ export const MessageBranchPage = ({
   return (
     <ButtonGroupText
       className={cn(
-        "border-none bg-transparent text-muted-foreground shadow-none",
-        className
+        "text-muted-foreground border-none bg-transparent shadow-none",
+        className,
       )}
       {...props}
     >
@@ -311,12 +308,12 @@ export const MessageResponse = memo(
     <Streamdown
       className={cn(
         "size-full [&>*:first-child]:mt-0 [&>*:last-child]:mb-0",
-        className
+        className,
       )}
       {...props}
     />
   ),
-  (prevProps, nextProps) => prevProps.children === nextProps.children
+  (prevProps, nextProps) => prevProps.children === nextProps.children,
 );
 
 MessageResponse.displayName = "MessageResponse";
@@ -343,7 +340,7 @@ export function MessageAttachment({
     <div
       className={cn(
         "group relative size-24 overflow-hidden rounded-lg",
-        className
+        className,
       )}
       {...props}
     >
@@ -359,7 +356,7 @@ export function MessageAttachment({
           {onRemove && (
             <Button
               aria-label="Remove attachment"
-              className="absolute top-2 right-2 size-6 rounded-full bg-background/80 p-0 opacity-0 backdrop-blur-sm transition-opacity hover:bg-background group-hover:opacity-100 [&>svg]:size-3"
+              className="bg-background/80 hover:bg-background absolute top-2 right-2 size-6 rounded-full p-0 opacity-0 backdrop-blur-sm transition-opacity group-hover:opacity-100 [&>svg]:size-3"
               onClick={(e) => {
                 e.stopPropagation();
                 onRemove();
@@ -376,7 +373,7 @@ export function MessageAttachment({
         <>
           <Tooltip>
             <TooltipTrigger asChild>
-              <div className="flex size-full shrink-0 items-center justify-center rounded-lg bg-muted text-muted-foreground">
+              <div className="bg-muted text-muted-foreground flex size-full shrink-0 items-center justify-center rounded-lg">
                 <PaperclipIcon className="size-4" />
               </div>
             </TooltipTrigger>
@@ -387,7 +384,7 @@ export function MessageAttachment({
           {onRemove && (
             <Button
               aria-label="Remove attachment"
-              className="size-6 shrink-0 rounded-full p-0 opacity-0 transition-opacity hover:bg-accent group-hover:opacity-100 [&>svg]:size-3"
+              className="hover:bg-accent size-6 shrink-0 rounded-full p-0 opacity-0 transition-opacity group-hover:opacity-100 [&>svg]:size-3"
               onClick={(e) => {
                 e.stopPropagation();
                 onRemove();
@@ -420,7 +417,7 @@ export function MessageAttachments({
     <div
       className={cn(
         "ml-auto flex w-fit flex-wrap items-start gap-2",
-        className
+        className,
       )}
       {...props}
     >
@@ -439,7 +436,7 @@ export const MessageToolbar = ({
   <div
     className={cn(
       "mt-4 flex w-full items-center justify-between gap-4",
-      className
+      className,
     )}
     {...props}
   >

frontend/src/components/ai-elements/prompt-input.tsx

@@ -37,7 +37,7 @@ import {
 import { cn } from "@/lib/utils";
 import type { ChatStatus, FileUIPart } from "ai";
 import {
-  CornerDownLeftIcon,
+  ArrowUpIcon,
   ImageIcon,
   Loader2Icon,
   MicIcon,
@@ -95,22 +95,22 @@ export type PromptInputControllerProps = {
   /** INTERNAL: Allows PromptInput to register its file textInput + "open" callback */
   __registerFileInput: (
     ref: RefObject<HTMLInputElement | null>,
-    open: () => void
+    open: () => void,
   ) => void;
 };
 
 const PromptInputController = createContext<PromptInputControllerProps | null>(
-  null
+  null,
 );
 const ProviderAttachmentsContext = createContext<AttachmentsContext | null>(
-  null
+  null,
 );
 
 export const usePromptInputController = () => {
   const ctx = useContext(PromptInputController);
   if (!ctx) {
     throw new Error(
-      "Wrap your component inside <PromptInputProvider> to use usePromptInputController()."
+      "Wrap your component inside <PromptInputProvider> to use usePromptInputController().",
     );
   }
   return ctx;
@@ -124,7 +124,7 @@ export const useProviderAttachments = () => {
   const ctx = useContext(ProviderAttachmentsContext);
   if (!ctx) {
     throw new Error(
-      "Wrap your component inside <PromptInputProvider> to use useProviderAttachments()."
+      "Wrap your component inside <PromptInputProvider> to use useProviderAttachments().",
     );
   }
   return ctx;
@@ -170,8 +170,8 @@ export function PromptInputProvider({
           url: URL.createObjectURL(file),
           mediaType: file.type,
           filename: file.name,
-        }))
-      )
+        })),
+      ),
     );
   }, []);
 
@@ -224,7 +224,7 @@ export function PromptInputProvider({
       openFileDialog,
       fileInputRef,
     }),
-    [attachmentFiles, add, remove, clear, openFileDialog]
+    [attachmentFiles, add, remove, clear, openFileDialog],
   );
 
   const __registerFileInput = useCallback(
@@ -232,7 +232,7 @@ export function PromptInputProvider({
       fileInputRef.current = ref.current;
       openRef.current = open;
     },
-    []
+    [],
   );
 
   const controller = useMemo<PromptInputControllerProps>(
@@ -245,7 +245,7 @@ export function PromptInputProvider({
       attachments,
       __registerFileInput,
     }),
-    [textInput, clearInput, attachments, __registerFileInput]
+    [textInput, clearInput, attachments, __registerFileInput],
   );
 
   return (
@@ -270,7 +270,7 @@ export const usePromptInputAttachments = () => {
   const context = provider ?? local;
   if (!context) {
     throw new Error(
-      "usePromptInputAttachments must be used within a PromptInput or PromptInputProvider"
+      "usePromptInputAttachments must be used within a PromptInput or PromptInputProvider",
     );
   }
   return context;
@@ -301,14 +301,14 @@ export function PromptInputAttachment({
       <HoverCardTrigger asChild>
         <div
           className={cn(
-            "group relative flex h-8 cursor-pointer select-none items-center gap-1.5 rounded-md border border-border px-1.5 font-medium text-sm transition-all hover:bg-accent hover:text-accent-foreground dark:hover:bg-accent/50",
-            className
+            "group border-border hover:bg-accent hover:text-accent-foreground dark:hover:bg-accent/50 relative flex h-8 cursor-pointer items-center gap-1.5 rounded-md border px-1.5 text-sm font-medium transition-all select-none",
+            className,
           )}
           key={data.id}
           {...props}
         >
           <div className="relative size-5 shrink-0">
-            <div className="absolute inset-0 flex size-5 items-center justify-center overflow-hidden rounded bg-background transition-opacity group-hover:opacity-0">
+            <div className="bg-background absolute inset-0 flex size-5 items-center justify-center overflow-hidden rounded transition-opacity group-hover:opacity-0">
               {isImage ? (
                 <img
                   alt={filename || "attachment"}
@@ -318,7 +318,7 @@ export function PromptInputAttachment({
                   width={20}
                 />
               ) : (
-                <div className="flex size-5 items-center justify-center text-muted-foreground">
+                <div className="text-muted-foreground flex size-5 items-center justify-center">
                   <PaperclipIcon className="size-3" />
                 </div>
               )}
@@ -356,11 +356,11 @@ export function PromptInputAttachment({
           )}
           <div className="flex items-center gap-2.5">
             <div className="min-w-0 flex-1 space-y-1 px-0.5">
-              <h4 className="truncate font-semibold text-sm leading-none">
+              <h4 className="truncate text-sm leading-none font-semibold">
                 {filename || (isImage ? "Image" : "Attachment")}
               </h4>
               {data.mediaType && (
-                <p className="truncate font-mono text-muted-foreground text-xs">
+                <p className="text-muted-foreground truncate font-mono text-xs">
                   {data.mediaType}
                 </p>
               )}
@@ -392,7 +392,7 @@ export function PromptInputAttachments({
 
   return (
     <div
-      className={cn("flex flex-wrap items-center gap-2 p-3 w-full", className)}
+      className={cn("flex w-full flex-wrap items-center gap-2 p-3", className)}
       {...props}
     >
       {attachments.files.map((file) => (
@@ -451,7 +451,7 @@ export type PromptInputProps = Omit<
   }) => void;
   onSubmit: (
     message: PromptInputMessage,
-    event: FormEvent<HTMLFormElement>
+    event: FormEvent<HTMLFormElement>,
   ) => void | Promise<void>;
 };
 
@@ -507,7 +507,7 @@ export const PromptInput = ({
         return f.type === pattern;
       });
     },
-    [accept]
+    [accept],
   );
 
   const addLocal = useCallback(
@@ -558,7 +558,7 @@ export const PromptInput = ({
         return prev.concat(next);
       });
     },
-    [matchesAccept, maxFiles, maxFileSize, onError]
+    [matchesAccept, maxFiles, maxFileSize, onError],
   );
 
   const removeLocal = useCallback(
@@ -570,7 +570,7 @@ export const PromptInput = ({
         }
         return prev.filter((file) => file.id !== id);
       }),
-    []
+    [],
   );
 
   const clearLocal = useCallback(
@@ -583,7 +583,7 @@ export const PromptInput = ({
         }
         return [];
       }),
-    []
+    [],
   );
 
   const add = usingProvider ? controller.attachments.add : addLocal;
@@ -611,7 +611,7 @@ export const PromptInput = ({
   useEffect(() => {
     const form = formRef.current;
     if (!form) return;
-    if (globalDrop) return // when global drop is on, let the document-level handler own drops
+    if (globalDrop) return; // when global drop is on, let the document-level handler own drops
 
     const onDragOver = (e: DragEvent) => {
       if (e.dataTransfer?.types?.includes("Files")) {
@@ -667,7 +667,7 @@ export const PromptInput = ({
       }
     },
     // eslint-disable-next-line react-hooks/exhaustive-deps -- cleanup only on unmount; filesRef always current
-    [usingProvider]
+    [usingProvider],
   );
 
   const handleChange: ChangeEventHandler<HTMLInputElement> = (event) => {
@@ -679,7 +679,7 @@ export const PromptInput = ({
   };
 
   const convertBlobUrlToDataUrl = async (
-    url: string
+    url: string,
   ): Promise<string | null> => {
     try {
       const response = await fetch(url);
@@ -704,7 +704,7 @@ export const PromptInput = ({
       openFileDialog,
       fileInputRef: inputRef,
     }),
-    [files, add, remove, clear, openFileDialog]
+    [files, add, remove, clear, openFileDialog],
   );
 
   const handleSubmit: FormEventHandler<HTMLFormElement> = (event) => {
@@ -736,7 +736,7 @@ export const PromptInput = ({
           };
         }
         return item;
-      })
+      }),
     )
       .then((convertedFiles: FileUIPart[]) => {
         try {
@@ -839,7 +839,7 @@ export const PromptInputTextarea = ({
       // Check if the submit button is disabled before submitting
       const form = e.currentTarget.form;
       const submitButton = form?.querySelector(
-        'button[type="submit"]'
+        'button[type="submit"]',
       ) as HTMLButtonElement | null;
       if (submitButton?.disabled) {
         return;
@@ -1030,7 +1030,7 @@ export const PromptInputSubmit = ({
   children,
   ...props
 }: PromptInputSubmitProps) => {
-  let Icon = <CornerDownLeftIcon className="size-4" />;
+  let Icon = <ArrowUpIcon className="size-4" />;
 
   if (status === "submitted") {
     Icon = <Loader2Icon className="size-4 animate-spin" />;
@@ -1123,7 +1123,7 @@ export const PromptInputSpeechButton = ({
 }: PromptInputSpeechButtonProps) => {
   const [isListening, setIsListening] = useState(false);
   const [recognition, setRecognition] = useState<SpeechRecognition | null>(
-    null
+    null,
   );
   const recognitionRef = useRef<SpeechRecognition | null>(null);
 
@@ -1202,8 +1202,8 @@ export const PromptInputSpeechButton = ({
     <PromptInputButton
       className={cn(
         "relative transition-all duration-200",
-        isListening && "animate-pulse bg-accent text-accent-foreground",
-        className
+        isListening && "bg-accent text-accent-foreground animate-pulse",
+        className,
       )}
       disabled={!recognition}
       onClick={toggleListening}
@@ -1230,9 +1230,9 @@ export const PromptInputSelectTrigger = ({
 }: PromptInputSelectTriggerProps) => (
   <SelectTrigger
     className={cn(
-      "border-none bg-transparent font-medium text-muted-foreground shadow-none transition-colors",
+      "text-muted-foreground border-none bg-transparent font-medium shadow-none transition-colors",
       "hover:bg-accent hover:text-foreground aria-expanded:bg-accent aria-expanded:text-foreground",
-      className
+      className,
     )}
     {...props}
   />
@@ -1282,7 +1282,7 @@ export type PromptInputHoverCardTriggerProps = ComponentProps<
 >;
 
 export const PromptInputHoverCardTrigger = (
-  props: PromptInputHoverCardTriggerProps
+  props: PromptInputHoverCardTriggerProps,
 ) => <HoverCardTrigger {...props} />;
 
 export type PromptInputHoverCardContentProps = ComponentProps<
@@ -1318,8 +1318,8 @@ export const PromptInputTabLabel = ({
 }: PromptInputTabLabelProps) => (
   <h3
     className={cn(
-      "mb-2 px-3 font-medium text-muted-foreground text-xs",
-      className
+      "text-muted-foreground mb-2 px-3 text-xs font-medium",
+      className,
     )}
     {...props}
   />
@@ -1342,8 +1342,8 @@ export const PromptInputTabItem = ({
 }: PromptInputTabItemProps) => (
   <div
     className={cn(
-      "flex items-center gap-2 px-3 py-2 text-xs hover:bg-accent",
-      className
+      "hover:bg-accent flex items-center gap-2 px-3 py-2 text-xs",
+      className,
     )}
     {...props}
   />

frontend/src/components/theme-provider.tsx

@@ -0,0 +1,10 @@
+"use client";
+
+import { ThemeProvider as NextThemesProvider } from "next-themes";
+
+export function ThemeProvider({
+  children,
+  ...props
+}: React.ComponentProps<typeof NextThemesProvider>) {
+  return <NextThemesProvider {...props}>{children}</NextThemesProvider>;
+}

frontend/src/components/ui/breadcrumb.tsx

@@ -0,0 +1,109 @@
+import * as React from "react"
+import { Slot } from "@radix-ui/react-slot"
+import { ChevronRight, MoreHorizontal } from "lucide-react"
+
+import { cn } from "@/lib/utils"
+
+function Breadcrumb({ ...props }: React.ComponentProps<"nav">) {
+  return <nav aria-label="breadcrumb" data-slot="breadcrumb" {...props} />
+}
+
+function BreadcrumbList({ className, ...props }: React.ComponentProps<"ol">) {
+  return (
+    <ol
+      data-slot="breadcrumb-list"
+      className={cn(
+        "text-muted-foreground flex flex-wrap items-center gap-1.5 text-sm break-words sm:gap-2.5",
+        className
+      )}
+      {...props}
+    />
+  )
+}
+
+function BreadcrumbItem({ className, ...props }: React.ComponentProps<"li">) {
+  return (
+    <li
+      data-slot="breadcrumb-item"
+      className={cn("inline-flex items-center gap-1.5", className)}
+      {...props}
+    />
+  )
+}
+
+function BreadcrumbLink({
+  asChild,
+  className,
+  ...props
+}: React.ComponentProps<"a"> & {
+  asChild?: boolean
+}) {
+  const Comp = asChild ? Slot : "a"
+
+  return (
+    <Comp
+      data-slot="breadcrumb-link"
+      className={cn("hover:text-foreground transition-colors", className)}
+      {...props}
+    />
+  )
+}
+
+function BreadcrumbPage({ className, ...props }: React.ComponentProps<"span">) {
+  return (
+    <span
+      data-slot="breadcrumb-page"
+      role="link"
+      aria-disabled="true"
+      aria-current="page"
+      className={cn("text-foreground font-normal", className)}
+      {...props}
+    />
+  )
+}
+
+function BreadcrumbSeparator({
+  children,
+  className,
+  ...props
+}: React.ComponentProps<"li">) {
+  return (
+    <li
+      data-slot="breadcrumb-separator"
+      role="presentation"
+      aria-hidden="true"
+      className={cn("[&>svg]:size-3.5", className)}
+      {...props}
+    >
+      {children ?? <ChevronRight />}
+    </li>
+  )
+}
+
+function BreadcrumbEllipsis({
+  className,
+  ...props
+}: React.ComponentProps<"span">) {
+  return (
+    <span
+      data-slot="breadcrumb-ellipsis"
+      role="presentation"
+      aria-hidden="true"
+      className={cn("flex size-9 items-center justify-center", className)}
+      {...props}
+    >
+      <MoreHorizontal className="size-4" />
+      <span className="sr-only">More</span>
+    </span>
+  )
+}
+
+export {
+  Breadcrumb,
+  BreadcrumbList,
+  BreadcrumbItem,
+  BreadcrumbLink,
+  BreadcrumbPage,
+  BreadcrumbSeparator,
+  BreadcrumbEllipsis,
+}

frontend/src/components/ui/button.tsx

@@ -1,24 +1,25 @@
-import * as React from "react"
-import { Slot } from "@radix-ui/react-slot"
-import { cva, type VariantProps } from "class-variance-authority"
+import * as React from "react";
+import { Slot } from "@radix-ui/react-slot";
+import { cva, type VariantProps } from "class-variance-authority";
 
-import { cn } from "@/lib/utils"
+import { cn } from "@/lib/utils";
 
 const buttonVariants = cva(
   "inline-flex items-center justify-center gap-2 whitespace-nowrap rounded-md text-sm font-medium transition-all disabled:pointer-events-none disabled:opacity-50 [&_svg]:pointer-events-none [&_svg:not([class*='size-'])]:size-4 shrink-0 [&_svg]:shrink-0 outline-none focus-visible:border-ring focus-visible:ring-ring/50 focus-visible:ring-[3px] aria-invalid:ring-destructive/20 dark:aria-invalid:ring-destructive/40 aria-invalid:border-destructive",
   {
     variants: {
       variant: {
-        default: "bg-primary text-primary-foreground hover:bg-primary/90",
+        default:
+          "cursor-pointer bg-primary text-primary-foreground hover:bg-primary/90",
         destructive:
-          "bg-destructive text-white hover:bg-destructive/90 focus-visible:ring-destructive/20 dark:focus-visible:ring-destructive/40 dark:bg-destructive/60",
+          "cursor-pointer bg-destructive text-white hover:bg-destructive/90 focus-visible:ring-destructive/20 dark:focus-visible:ring-destructive/40 dark:bg-destructive/60",
         outline:
-          "border bg-background shadow-xs hover:bg-accent hover:text-accent-foreground dark:bg-input/30 dark:border-input dark:hover:bg-input/50",
+          "cursor-pointer border bg-background shadow-xs hover:bg-accent hover:text-accent-foreground dark:bg-input/30 dark:border-input dark:hover:bg-input/50",
         secondary:
-          "bg-secondary text-secondary-foreground hover:bg-secondary/80",
+          "cursor-pointer bg-secondary text-secondary-foreground hover:bg-secondary/80",
         ghost:
-          "hover:bg-accent hover:text-accent-foreground dark:hover:bg-accent/50",
-        link: "text-primary underline-offset-4 hover:underline",
+          "cursor-pointer hover:bg-accent hover:text-accent-foreground dark:hover:bg-accent/50",
+        link: "cursor-pointer text-primary underline-offset-4 hover:underline",
       },
       size: {
         default: "h-9 px-4 py-2 has-[>svg]:px-3",
@@ -33,8 +34,8 @@ const buttonVariants = cva(
       variant: "default",
       size: "default",
     },
-  }
-)
+  },
+);
 
 function Button({
   className,
@@ -44,9 +45,9 @@ function Button({
   ...props
 }: React.ComponentProps<"button"> &
   VariantProps<typeof buttonVariants> & {
-    asChild?: boolean
+    asChild?: boolean;
   }) {
-  const Comp = asChild ? Slot : "button"
+  const Comp = asChild ? Slot : "button";
 
   return (
     <Comp
@@ -56,7 +57,7 @@ function Button({
       className={cn(buttonVariants({ variant, size, className }))}
       {...props}
     />
-  )
+  );
 }
 
-export { Button, buttonVariants }
+export { Button, buttonVariants };

frontend/src/components/ui/collapsible.tsx

@@ -1,22 +1,26 @@
-"use client"
+"use client";
 
-import * as CollapsiblePrimitive from "@radix-ui/react-collapsible"
+import * as CollapsiblePrimitive from "@radix-ui/react-collapsible";
+
+import { cn } from "@/lib/utils";
 
 function Collapsible({
   ...props
 }: React.ComponentProps<typeof CollapsiblePrimitive.Root>) {
-  return <CollapsiblePrimitive.Root data-slot="collapsible" {...props} />
+  return <CollapsiblePrimitive.Root data-slot="collapsible" {...props} />;
 }
 
 function CollapsibleTrigger({
+  className,
   ...props
 }: React.ComponentProps<typeof CollapsiblePrimitive.CollapsibleTrigger>) {
   return (
     <CollapsiblePrimitive.CollapsibleTrigger
       data-slot="collapsible-trigger"
+      className={cn("cursor-pointer", className)}
       {...props}
     />
-  )
+  );
 }
 
 function CollapsibleContent({
@@ -27,7 +31,7 @@ function CollapsibleContent({
       data-slot="collapsible-content"
       {...props}
     />
-  )
+  );
 }
 
-export { Collapsible, CollapsibleTrigger, CollapsibleContent }
+export { Collapsible, CollapsibleTrigger, CollapsibleContent };

frontend/src/components/ui/sheet.tsx

@@ -0,0 +1,139 @@
+"use client"
+
+import * as React from "react"
+import * as SheetPrimitive from "@radix-ui/react-dialog"
+import { XIcon } from "lucide-react"
+
+import { cn } from "@/lib/utils"
+
+function Sheet({ ...props }: React.ComponentProps<typeof SheetPrimitive.Root>) {
+  return <SheetPrimitive.Root data-slot="sheet" {...props} />
+}
+
+function SheetTrigger({
+  ...props
+}: React.ComponentProps<typeof SheetPrimitive.Trigger>) {
+  return <SheetPrimitive.Trigger data-slot="sheet-trigger" {...props} />
+}
+
+function SheetClose({
+  ...props
+}: React.ComponentProps<typeof SheetPrimitive.Close>) {
+  return <SheetPrimitive.Close data-slot="sheet-close" {...props} />
+}
+
+function SheetPortal({
+  ...props
+}: React.ComponentProps<typeof SheetPrimitive.Portal>) {
+  return <SheetPrimitive.Portal data-slot="sheet-portal" {...props} />
+}
+
+function SheetOverlay({
+  className,
+  ...props
+}: React.ComponentProps<typeof SheetPrimitive.Overlay>) {
+  return (
+    <SheetPrimitive.Overlay
+      data-slot="sheet-overlay"
+      className={cn(
+        "data-[state=open]:animate-in data-[state=closed]:animate-out data-[state=closed]:fade-out-0 data-[state=open]:fade-in-0 fixed inset-0 z-50 bg-black/50",
+        className
+      )}
+      {...props}
+    />
+  )
+}
+
+function SheetContent({
+  className,
+  children,
+  side = "right",
+  ...props
+}: React.ComponentProps<typeof SheetPrimitive.Content> & {
+  side?: "top" | "right" | "bottom" | "left"
+}) {
+  return (
+    <SheetPortal>
+      <SheetOverlay />
+      <SheetPrimitive.Content
+        data-slot="sheet-content"
+        className={cn(
+          "bg-background data-[state=open]:animate-in data-[state=closed]:animate-out fixed z-50 flex flex-col gap-4 shadow-lg transition ease-in-out data-[state=closed]:duration-300 data-[state=open]:duration-500",
+          side === "right" &&
+            "data-[state=closed]:slide-out-to-right data-[state=open]:slide-in-from-right inset-y-0 right-0 h-full w-3/4 border-l sm:max-w-sm",
+          side === "left" &&
+            "data-[state=closed]:slide-out-to-left data-[state=open]:slide-in-from-left inset-y-0 left-0 h-full w-3/4 border-r sm:max-w-sm",
+          side === "top" &&
+            "data-[state=closed]:slide-out-to-top data-[state=open]:slide-in-from-top inset-x-0 top-0 h-auto border-b",
+          side === "bottom" &&
+            "data-[state=closed]:slide-out-to-bottom data-[state=open]:slide-in-from-bottom inset-x-0 bottom-0 h-auto border-t",
+          className
+        )}
+        {...props}
+      >
+        {children}
+        <SheetPrimitive.Close className="ring-offset-background focus:ring-ring data-[state=open]:bg-secondary absolute top-4 right-4 rounded-xs opacity-70 transition-opacity hover:opacity-100 focus:ring-2 focus:ring-offset-2 focus:outline-hidden disabled:pointer-events-none">
+          <XIcon className="size-4" />
+          <span className="sr-only">Close</span>
+        </SheetPrimitive.Close>
+      </SheetPrimitive.Content>
+    </SheetPortal>
+  )
+}
+
+function SheetHeader({ className, ...props }: React.ComponentProps<"div">) {
+  return (
+    <div
+      data-slot="sheet-header"
+      className={cn("flex flex-col gap-1.5 p-4", className)}
+      {...props}
+    />
+  )
+}
+
+function SheetFooter({ className, ...props }: React.ComponentProps<"div">) {
+  return (
+    <div
+      data-slot="sheet-footer"
+      className={cn("mt-auto flex flex-col gap-2 p-4", className)}
+      {...props}
+    />
+  )
+}
+
+function SheetTitle({
+  className,
+  ...props
+}: React.ComponentProps<typeof SheetPrimitive.Title>) {
+  return (
+    <SheetPrimitive.Title
+      data-slot="sheet-title"
+      className={cn("text-foreground font-semibold", className)}
+      {...props}
+    />
+  )
+}
+
+function SheetDescription({
+  className,
+  ...props
+}: React.ComponentProps<typeof SheetPrimitive.Description>) {
+  return (
+    <SheetPrimitive.Description
+      data-slot="sheet-description"
+      className={cn("text-muted-foreground text-sm", className)}
+      {...props}
+    />
+  )
+}
+
+export {
+  Sheet,
+  SheetTrigger,
+  SheetClose,
+  SheetContent,
+  SheetHeader,
+  SheetFooter,
+  SheetTitle,
+  SheetDescription,
+}

frontend/src/components/ui/sidebar.tsx

@@ -0,0 +1,726 @@
+"use client";
+
+import * as React from "react";
+import { Slot } from "@radix-ui/react-slot";
+import { cva, type VariantProps } from "class-variance-authority";
+import { PanelLeftCloseIcon, PanelLeftOpenIcon } from "lucide-react";
+
+import { useIsMobile } from "@/hooks/use-mobile";
+import { cn } from "@/lib/utils";
+import { Button } from "@/components/ui/button";
+import { Input } from "@/components/ui/input";
+import { Separator } from "@/components/ui/separator";
+import {
+  Sheet,
+  SheetContent,
+  SheetDescription,
+  SheetHeader,
+  SheetTitle,
+} from "@/components/ui/sheet";
+import { Skeleton } from "@/components/ui/skeleton";
+import {
+  Tooltip,
+  TooltipContent,
+  TooltipProvider,
+  TooltipTrigger,
+} from "@/components/ui/tooltip";
+
+const SIDEBAR_COOKIE_NAME = "sidebar_state";
+const SIDEBAR_COOKIE_MAX_AGE = 60 * 60 * 24 * 7;
+const SIDEBAR_WIDTH = "16rem";
+const SIDEBAR_WIDTH_MOBILE = "18rem";
+const SIDEBAR_WIDTH_ICON = "3rem";
+const SIDEBAR_KEYBOARD_SHORTCUT = "b";
+
+type SidebarContextProps = {
+  state: "expanded" | "collapsed";
+  open: boolean;
+  setOpen: (open: boolean) => void;
+  openMobile: boolean;
+  setOpenMobile: (open: boolean) => void;
+  isMobile: boolean;
+  toggleSidebar: () => void;
+};
+
+const SidebarContext = React.createContext<SidebarContextProps | null>(null);
+
+function useSidebar() {
+  const context = React.useContext(SidebarContext);
+  if (!context) {
+    throw new Error("useSidebar must be used within a SidebarProvider.");
+  }
+
+  return context;
+}
+
+function SidebarProvider({
+  defaultOpen = true,
+  open: openProp,
+  onOpenChange: setOpenProp,
+  className,
+  style,
+  children,
+  ...props
+}: React.ComponentProps<"div"> & {
+  defaultOpen?: boolean;
+  open?: boolean;
+  onOpenChange?: (open: boolean) => void;
+}) {
+  const isMobile = useIsMobile();
+  const [openMobile, setOpenMobile] = React.useState(false);
+
+  // This is the internal state of the sidebar.
+  // We use openProp and setOpenProp for control from outside the component.
+  const [_open, _setOpen] = React.useState(defaultOpen);
+  const open = openProp ?? _open;
+  const setOpen = React.useCallback(
+    (value: boolean | ((value: boolean) => boolean)) => {
+      const openState = typeof value === "function" ? value(open) : value;
+      if (setOpenProp) {
+        setOpenProp(openState);
+      } else {
+        _setOpen(openState);
+      }
+
+      // This sets the cookie to keep the sidebar state.
+      document.cookie = `${SIDEBAR_COOKIE_NAME}=${openState}; path=/; max-age=${SIDEBAR_COOKIE_MAX_AGE}`;
+    },
+    [setOpenProp, open],
+  );
+
+  // Helper to toggle the sidebar.
+  const toggleSidebar = React.useCallback(() => {
+    return isMobile ? setOpenMobile((open) => !open) : setOpen((open) => !open);
+  }, [isMobile, setOpen, setOpenMobile]);
+
+  // Adds a keyboard shortcut to toggle the sidebar.
+  React.useEffect(() => {
+    const handleKeyDown = (event: KeyboardEvent) => {
+      if (
+        event.key === SIDEBAR_KEYBOARD_SHORTCUT &&
+        (event.metaKey || event.ctrlKey)
+      ) {
+        event.preventDefault();
+        toggleSidebar();
+      }
+    };
+
+    window.addEventListener("keydown", handleKeyDown);
+    return () => window.removeEventListener("keydown", handleKeyDown);
+  }, [toggleSidebar]);
+
+  // We add a state so that we can do data-state="expanded" or "collapsed".
+  // This makes it easier to style the sidebar with Tailwind classes.
+  const state = open ? "expanded" : "collapsed";
+
+  const contextValue = React.useMemo<SidebarContextProps>(
+    () => ({
+      state,
+      open,
+      setOpen,
+      isMobile,
+      openMobile,
+      setOpenMobile,
+      toggleSidebar,
+    }),
+    [state, open, setOpen, isMobile, openMobile, setOpenMobile, toggleSidebar],
+  );
+
+  return (
+    <SidebarContext.Provider value={contextValue}>
+      <TooltipProvider delayDuration={0}>
+        <div
+          data-slot="sidebar-wrapper"
+          style={
+            {
+              "--sidebar-width": SIDEBAR_WIDTH,
+              "--sidebar-width-icon": SIDEBAR_WIDTH_ICON,
+              ...style,
+            } as React.CSSProperties
+          }
+          className={cn(
+            "group/sidebar-wrapper has-data-[variant=inset]:bg-sidebar flex min-h-svh w-full",
+            className,
+          )}
+          {...props}
+        >
+          {children}
+        </div>
+      </TooltipProvider>
+    </SidebarContext.Provider>
+  );
+}
+
+function Sidebar({
+  side = "left",
+  variant = "sidebar",
+  collapsible = "offcanvas",
+  className,
+  children,
+  ...props
+}: React.ComponentProps<"div"> & {
+  side?: "left" | "right";
+  variant?: "sidebar" | "floating" | "inset";
+  collapsible?: "offcanvas" | "icon" | "none";
+}) {
+  const { isMobile, state, openMobile, setOpenMobile } = useSidebar();
+
+  if (collapsible === "none") {
+    return (
+      <div
+        data-slot="sidebar"
+        className={cn(
+          "bg-sidebar text-sidebar-foreground flex h-full w-(--sidebar-width) flex-col",
+          className,
+        )}
+        {...props}
+      >
+        {children}
+      </div>
+    );
+  }
+
+  if (isMobile) {
+    return (
+      <Sheet open={openMobile} onOpenChange={setOpenMobile} {...props}>
+        <SheetContent
+          data-sidebar="sidebar"
+          data-slot="sidebar"
+          data-mobile="true"
+          className="bg-sidebar text-sidebar-foreground w-(--sidebar-width) p-0 [&>button]:hidden"
+          style={
+            {
+              "--sidebar-width": SIDEBAR_WIDTH_MOBILE,
+            } as React.CSSProperties
+          }
+          side={side}
+        >
+          <SheetHeader className="sr-only">
+            <SheetTitle>Sidebar</SheetTitle>
+            <SheetDescription>Displays the mobile sidebar.</SheetDescription>
+          </SheetHeader>
+          <div className="flex h-full w-full flex-col">{children}</div>
+        </SheetContent>
+      </Sheet>
+    );
+  }
+
+  return (
+    <div
+      className="group peer text-sidebar-foreground hidden md:block"
+      data-state={state}
+      data-collapsible={state === "collapsed" ? collapsible : ""}
+      data-variant={variant}
+      data-side={side}
+      data-slot="sidebar"
+    >
+      {/* This is what handles the sidebar gap on desktop */}
+      <div
+        data-slot="sidebar-gap"
+        className={cn(
+          "relative w-(--sidebar-width) bg-transparent transition-[width] duration-200 ease-linear",
+          "group-data-[collapsible=offcanvas]:w-0",
+          "group-data-[side=right]:rotate-180",
+          variant === "floating" || variant === "inset"
+            ? "group-data-[collapsible=icon]:w-[calc(var(--sidebar-width-icon)+(--spacing(4)))]"
+            : "group-data-[collapsible=icon]:w-(--sidebar-width-icon)",
+        )}
+      />
+      <div
+        data-slot="sidebar-container"
+        className={cn(
+          "fixed inset-y-0 z-10 hidden h-svh w-(--sidebar-width) transition-[left,right,width] duration-200 ease-linear md:flex",
+          side === "left"
+            ? "left-0 group-data-[collapsible=offcanvas]:left-[calc(var(--sidebar-width)*-1)]"
+            : "right-0 group-data-[collapsible=offcanvas]:right-[calc(var(--sidebar-width)*-1)]",
+          // Adjust the padding for floating and inset variants.
+          variant === "floating" || variant === "inset"
+            ? "p-2 group-data-[collapsible=icon]:w-[calc(var(--sidebar-width-icon)+(--spacing(4))+2px)]"
+            : "group-data-[collapsible=icon]:w-(--sidebar-width-icon) group-data-[side=left]:border-r group-data-[side=right]:border-l",
+          className,
+        )}
+        {...props}
+      >
+        <div
+          data-sidebar="sidebar"
+          data-slot="sidebar-inner"
+          className="bg-sidebar group-data-[variant=floating]:border-sidebar-border flex h-full w-full flex-col group-data-[variant=floating]:rounded-lg group-data-[variant=floating]:border group-data-[variant=floating]:shadow-sm"
+        >
+          {children}
+        </div>
+      </div>
+    </div>
+  );
+}
+
+function SidebarTrigger({
+  className,
+  onClick,
+  ...props
+}: React.ComponentProps<typeof Button>) {
+  const { open, toggleSidebar } = useSidebar();
+
+  return (
+    <Button
+      data-sidebar="trigger"
+      data-slot="sidebar-trigger"
+      variant="ghost"
+      size="icon"
+      className={cn("size-7 opacity-50 hover:opacity-100", className)}
+      onClick={(event) => {
+        onClick?.(event);
+        toggleSidebar();
+      }}
+      {...props}
+    >
+      {open ? <PanelLeftCloseIcon /> : <PanelLeftOpenIcon />}
+      <span className="sr-only">Toggle Sidebar</span>
+    </Button>
+  );
+}
+
+function SidebarRail({ className, ...props }: React.ComponentProps<"button">) {
+  const { toggleSidebar } = useSidebar();
+
+  return (
+    <button
+      data-sidebar="rail"
+      data-slot="sidebar-rail"
+      aria-label="Toggle Sidebar"
+      tabIndex={-1}
+      onClick={toggleSidebar}
+      title="Toggle Sidebar"
+      className={cn(
+        "hover:after:bg-sidebar-border absolute inset-y-0 z-20 hidden w-4 -translate-x-1/2 transition-all ease-linear group-data-[side=left]:-right-4 group-data-[side=right]:left-0 after:absolute after:inset-y-0 after:left-1/2 after:w-[2px] sm:flex",
+        "in-data-[side=left]:cursor-w-resize in-data-[side=right]:cursor-e-resize",
+        "[[data-side=left][data-state=collapsed]_&]:cursor-e-resize [[data-side=right][data-state=collapsed]_&]:cursor-w-resize",
+        "hover:group-data-[collapsible=offcanvas]:bg-sidebar group-data-[collapsible=offcanvas]:translate-x-0 group-data-[collapsible=offcanvas]:after:left-full",
+        "[[data-side=left][data-collapsible=offcanvas]_&]:-right-2",
+        "[[data-side=right][data-collapsible=offcanvas]_&]:-left-2",
+        className,
+      )}
+      {...props}
+    />
+  );
+}
+
+function SidebarInset({ className, ...props }: React.ComponentProps<"main">) {
+  return (
+    <main
+      data-slot="sidebar-inset"
+      className={cn(
+        "bg-background relative flex w-full flex-1 flex-col",
+        "md:peer-data-[variant=inset]:m-2 md:peer-data-[variant=inset]:ml-0 md:peer-data-[variant=inset]:rounded-xl md:peer-data-[variant=inset]:shadow-sm md:peer-data-[variant=inset]:peer-data-[state=collapsed]:ml-2",
+        className,
+      )}
+      {...props}
+    />
+  );
+}
+
+function SidebarInput({
+  className,
+  ...props
+}: React.ComponentProps<typeof Input>) {
+  return (
+    <Input
+      data-slot="sidebar-input"
+      data-sidebar="input"
+      className={cn("bg-background h-8 w-full shadow-none", className)}
+      {...props}
+    />
+  );
+}
+
+function SidebarHeader({ className, ...props }: React.ComponentProps<"div">) {
+  return (
+    <div
+      data-slot="sidebar-header"
+      data-sidebar="header"
+      className={cn("flex flex-col gap-2 p-2", className)}
+      {...props}
+    />
+  );
+}
+
+function SidebarFooter({ className, ...props }: React.ComponentProps<"div">) {
+  return (
+    <div
+      data-slot="sidebar-footer"
+      data-sidebar="footer"
+      className={cn("flex flex-col gap-2 p-2", className)}
+      {...props}
+    />
+  );
+}
+
+function SidebarSeparator({
+  className,
+  ...props
+}: React.ComponentProps<typeof Separator>) {
+  return (
+    <Separator
+      data-slot="sidebar-separator"
+      data-sidebar="separator"
+      className={cn("bg-sidebar-border mx-2 w-auto", className)}
+      {...props}
+    />
+  );
+}
+
+function SidebarContent({ className, ...props }: React.ComponentProps<"div">) {
+  return (
+    <div
+      data-slot="sidebar-content"
+      data-sidebar="content"
+      className={cn(
+        "flex min-h-0 flex-1 flex-col gap-2 overflow-auto group-data-[collapsible=icon]:overflow-hidden",
+        className,
+      )}
+      {...props}
+    />
+  );
+}
+
+function SidebarGroup({ className, ...props }: React.ComponentProps<"div">) {
+  return (
+    <div
+      data-slot="sidebar-group"
+      data-sidebar="group"
+      className={cn("relative flex w-full min-w-0 flex-col p-2", className)}
+      {...props}
+    />
+  );
+}
+
+function SidebarGroupLabel({
+  className,
+  asChild = false,
+  ...props
+}: React.ComponentProps<"div"> & { asChild?: boolean }) {
+  const Comp = asChild ? Slot : "div";
+
+  return (
+    <Comp
+      data-slot="sidebar-group-label"
+      data-sidebar="group-label"
+      className={cn(
+        "text-sidebar-foreground/70 ring-sidebar-ring flex h-8 shrink-0 items-center rounded-md px-2 text-xs font-medium outline-hidden transition-[margin,opacity] duration-200 ease-linear focus-visible:ring-2 [&>svg]:size-4 [&>svg]:shrink-0",
+        "group-data-[collapsible=icon]:-mt-8 group-data-[collapsible=icon]:opacity-0",
+        className,
+      )}
+      {...props}
+    />
+  );
+}
+
+function SidebarGroupAction({
+  className,
+  asChild = false,
+  ...props
+}: React.ComponentProps<"button"> & { asChild?: boolean }) {
+  const Comp = asChild ? Slot : "button";
+
+  return (
+    <Comp
+      data-slot="sidebar-group-action"
+      data-sidebar="group-action"
+      className={cn(
+        "text-sidebar-foreground ring-sidebar-ring hover:bg-sidebar-accent hover:text-sidebar-accent-foreground absolute top-3.5 right-3 flex aspect-square w-5 items-center justify-center rounded-md p-0 outline-hidden transition-transform focus-visible:ring-2 [&>svg]:size-4 [&>svg]:shrink-0",
+        // Increases the hit area of the button on mobile.
+        "after:absolute after:-inset-2 md:after:hidden",
+        "group-data-[collapsible=icon]:hidden",
+        className,
+      )}
+      {...props}
+    />
+  );
+}
+
+function SidebarGroupContent({
+  className,
+  ...props
+}: React.ComponentProps<"div">) {
+  return (
+    <div
+      data-slot="sidebar-group-content"
+      data-sidebar="group-content"
+      className={cn("w-full text-sm", className)}
+      {...props}
+    />
+  );
+}
+
+function SidebarMenu({ className, ...props }: React.ComponentProps<"ul">) {
+  return (
+    <ul
+      data-slot="sidebar-menu"
+      data-sidebar="menu"
+      className={cn("flex w-full min-w-0 flex-col gap-1", className)}
+      {...props}
+    />
+  );
+}
+
+function SidebarMenuItem({ className, ...props }: React.ComponentProps<"li">) {
+  return (
+    <li
+      data-slot="sidebar-menu-item"
+      data-sidebar="menu-item"
+      className={cn("group/menu-item relative", className)}
+      {...props}
+    />
+  );
+}
+
+const sidebarMenuButtonVariants = cva(
+  "peer/menu-button flex w-full items-center gap-2 overflow-hidden rounded-md p-2 text-left text-sm outline-hidden ring-sidebar-ring transition-[width,height,padding] hover:bg-sidebar-accent hover:text-sidebar-accent-foreground focus-visible:ring-2 active:bg-sidebar-accent active:text-sidebar-accent-foreground disabled:pointer-events-none disabled:opacity-50 group-has-data-[sidebar=menu-action]/menu-item:pr-8 aria-disabled:pointer-events-none aria-disabled:opacity-50 data-[active=true]:bg-sidebar-accent data-[active=true]:font-medium data-[active=true]:text-sidebar-accent-foreground data-[state=open]:hover:bg-sidebar-accent data-[state=open]:hover:text-sidebar-accent-foreground group-data-[collapsible=icon]:size-8! group-data-[collapsible=icon]:p-2! [&>span:last-child]:truncate [&>svg]:size-4 [&>svg]:shrink-0",
+  {
+    variants: {
+      variant: {
+        default: "hover:bg-sidebar-accent hover:text-sidebar-accent-foreground",
+        outline:
+          "bg-background shadow-[0_0_0_1px_hsl(var(--sidebar-border))] hover:bg-sidebar-accent hover:text-sidebar-accent-foreground hover:shadow-[0_0_0_1px_hsl(var(--sidebar-accent))]",
+      },
+      size: {
+        default: "h-8 text-sm",
+        sm: "h-7 text-xs",
+        lg: "h-12 text-sm group-data-[collapsible=icon]:p-0!",
+      },
+    },
+    defaultVariants: {
+      variant: "default",
+      size: "default",
+    },
+  },
+);
+
+function SidebarMenuButton({
+  asChild = false,
+  isActive = false,
+  variant = "default",
+  size = "default",
+  tooltip,
+  className,
+  ...props
+}: React.ComponentProps<"button"> & {
+  asChild?: boolean;
+  isActive?: boolean;
+  tooltip?: string | React.ComponentProps<typeof TooltipContent>;
+} & VariantProps<typeof sidebarMenuButtonVariants>) {
+  const Comp = asChild ? Slot : "button";
+  const { isMobile, state } = useSidebar();
+
+  const button = (
+    <Comp
+      data-slot="sidebar-menu-button"
+      data-sidebar="menu-button"
+      data-size={size}
+      data-active={isActive}
+      className={cn(sidebarMenuButtonVariants({ variant, size }), className)}
+      {...props}
+    />
+  );
+
+  if (!tooltip) {
+    return button;
+  }
+
+  if (typeof tooltip === "string") {
+    tooltip = {
+      children: tooltip,
+    };
+  }
+
+  return (
+    <Tooltip>
+      <TooltipTrigger asChild>{button}</TooltipTrigger>
+      <TooltipContent
+        side="right"
+        align="center"
+        hidden={state !== "collapsed" || isMobile}
+        {...tooltip}
+      />
+    </Tooltip>
+  );
+}
+
+function SidebarMenuAction({
+  className,
+  asChild = false,
+  showOnHover = false,
+  ...props
+}: React.ComponentProps<"button"> & {
+  asChild?: boolean;
+  showOnHover?: boolean;
+}) {
+  const Comp = asChild ? Slot : "button";
+
+  return (
+    <Comp
+      data-slot="sidebar-menu-action"
+      data-sidebar="menu-action"
+      className={cn(
+        "text-sidebar-foreground ring-sidebar-ring hover:bg-sidebar-accent hover:text-sidebar-accent-foreground peer-hover/menu-button:text-sidebar-accent-foreground absolute top-1.5 right-1 flex aspect-square w-5 items-center justify-center rounded-md p-0 outline-hidden transition-transform focus-visible:ring-2 [&>svg]:size-4 [&>svg]:shrink-0",
+        // Increases the hit area of the button on mobile.
+        "after:absolute after:-inset-2 md:after:hidden",
+        "peer-data-[size=sm]/menu-button:top-1",
+        "peer-data-[size=default]/menu-button:top-1.5",
+        "peer-data-[size=lg]/menu-button:top-2.5",
+        "group-data-[collapsible=icon]:hidden",
+        showOnHover &&
+          "peer-data-[active=true]/menu-button:text-sidebar-accent-foreground group-focus-within/menu-item:opacity-100 group-hover/menu-item:opacity-100 data-[state=open]:opacity-100 md:opacity-0",
+        className,
+      )}
+      {...props}
+    />
+  );
+}
+
+function SidebarMenuBadge({
+  className,
+  ...props
+}: React.ComponentProps<"div">) {
+  return (
+    <div
+      data-slot="sidebar-menu-badge"
+      data-sidebar="menu-badge"
+      className={cn(
+        "text-sidebar-foreground pointer-events-none absolute right-1 flex h-5 min-w-5 items-center justify-center rounded-md px-1 text-xs font-medium tabular-nums select-none",
+        "peer-hover/menu-button:text-sidebar-accent-foreground peer-data-[active=true]/menu-button:text-sidebar-accent-foreground",
+        "peer-data-[size=sm]/menu-button:top-1",
+        "peer-data-[size=default]/menu-button:top-1.5",
+        "peer-data-[size=lg]/menu-button:top-2.5",
+        "group-data-[collapsible=icon]:hidden",
+        className,
+      )}
+      {...props}
+    />
+  );
+}
+
+function SidebarMenuSkeleton({
+  className,
+  showIcon = false,
+  ...props
+}: React.ComponentProps<"div"> & {
+  showIcon?: boolean;
+}) {
+  // Random width between 50 to 90%.
+  const width = React.useMemo(() => {
+    return `${Math.floor(Math.random() * 40) + 50}%`;
+  }, []);
+
+  return (
+    <div
+      data-slot="sidebar-menu-skeleton"
+      data-sidebar="menu-skeleton"
+      className={cn("flex h-8 items-center gap-2 rounded-md px-2", className)}
+      {...props}
+    >
+      {showIcon && (
+        <Skeleton
+          className="size-4 rounded-md"
+          data-sidebar="menu-skeleton-icon"
+        />
+      )}
+      <Skeleton
+        className="h-4 max-w-(--skeleton-width) flex-1"
+        data-sidebar="menu-skeleton-text"
+        style={
+          {
+            "--skeleton-width": width,
+          } as React.CSSProperties
+        }
+      />
+    </div>
+  );
+}
+
+function SidebarMenuSub({ className, ...props }: React.ComponentProps<"ul">) {
+  return (
+    <ul
+      data-slot="sidebar-menu-sub"
+      data-sidebar="menu-sub"
+      className={cn(
+        "border-sidebar-border mx-3.5 flex min-w-0 translate-x-px flex-col gap-1 border-l px-2.5 py-0.5",
+        "group-data-[collapsible=icon]:hidden",
+        className,
+      )}
+      {...props}
+    />
+  );
+}
+
+function SidebarMenuSubItem({
+  className,
+  ...props
+}: React.ComponentProps<"li">) {
+  return (
+    <li
+      data-slot="sidebar-menu-sub-item"
+      data-sidebar="menu-sub-item"
+      className={cn("group/menu-sub-item relative", className)}
+      {...props}
+    />
+  );
+}
+
+function SidebarMenuSubButton({
+  asChild = false,
+  size = "md",
+  isActive = false,
+  className,
+  ...props
+}: React.ComponentProps<"a"> & {
+  asChild?: boolean;
+  size?: "sm" | "md";
+  isActive?: boolean;
+}) {
+  const Comp = asChild ? Slot : "a";
+
+  return (
+    <Comp
+      data-slot="sidebar-menu-sub-button"
+      data-sidebar="menu-sub-button"
+      data-size={size}
+      data-active={isActive}
+      className={cn(
+        "text-sidebar-foreground ring-sidebar-ring hover:bg-sidebar-accent hover:text-sidebar-accent-foreground active:bg-sidebar-accent active:text-sidebar-accent-foreground [&>svg]:text-sidebar-accent-foreground flex h-7 min-w-0 -translate-x-px items-center gap-2 overflow-hidden rounded-md px-2 outline-hidden focus-visible:ring-2 disabled:pointer-events-none disabled:opacity-50 aria-disabled:pointer-events-none aria-disabled:opacity-50 [&>span:last-child]:truncate [&>svg]:size-4 [&>svg]:shrink-0",
+        "data-[active=true]:bg-sidebar-accent data-[active=true]:text-sidebar-accent-foreground",
+        size === "sm" && "text-xs",
+        size === "md" && "text-sm",
+        "group-data-[collapsible=icon]:hidden",
+        className,
+      )}
+      {...props}
+    />
+  );
+}
+
+export {
+  Sidebar,
+  SidebarContent,
+  SidebarFooter,
+  SidebarGroup,
+  SidebarGroupAction,
+  SidebarGroupContent,
+  SidebarGroupLabel,
+  SidebarHeader,
+  SidebarInput,
+  SidebarInset,
+  SidebarMenu,
+  SidebarMenuAction,
+  SidebarMenuBadge,
+  SidebarMenuButton,
+  SidebarMenuItem,
+  SidebarMenuSkeleton,
+  SidebarMenuSub,
+  SidebarMenuSubButton,
+  SidebarMenuSubItem,
+  SidebarProvider,
+  SidebarRail,
+  SidebarSeparator,
+  SidebarTrigger,
+  useSidebar,
+};

frontend/src/components/ui/skeleton.tsx

@@ -0,0 +1,13 @@
+import { cn } from "@/lib/utils"
+
+function Skeleton({ className, ...props }: React.ComponentProps<"div">) {
+  return (
+    <div
+      data-slot="skeleton"
+      className={cn("bg-accent animate-pulse rounded-md", className)}
+      {...props}
+    />
+  )
+}
+
+export { Skeleton }

frontend/src/components/workspace/github-icon.tsx

@@ -0,0 +1,14 @@
+export function GithubIcon(props: React.SVGProps<SVGSVGElement>) {
+  return (
+    <svg
+      height={32}
+      aria-hidden="true"
+      viewBox="0 0 24 24"
+      width={32}
+      fill="currentColor"
+      {...props}
+    >
+      <path d="M12 1C5.923 1 1 5.923 1 12c0 4.867 3.149 8.979 7.521 10.436.55.096.756-.233.756-.522 0-.262-.013-1.128-.013-2.049-2.764.509-3.479-.674-3.699-1.292-.124-.317-.66-1.293-1.127-1.554-.385-.207-.936-.715-.014-.729.866-.014 1.485.797 1.691 1.128.99 1.663 2.571 1.196 3.204.907.096-.715.385-1.196.701-1.471-2.448-.275-5.005-1.224-5.005-5.432 0-1.196.426-2.186 1.128-2.956-.111-.275-.496-1.402.11-2.915 0 0 .921-.288 3.024 1.128a10.193 10.193 0 0 1 2.75-.371c.936 0 1.871.123 2.75.371 2.104-1.43 3.025-1.128 3.025-1.128.605 1.513.221 2.64.111 2.915.701.77 1.127 1.747 1.127 2.956 0 4.222-2.571 5.157-5.019 5.432.399.344.743 1.004.743 2.035 0 1.471-.014 2.654-.014 3.025 0 .289.206.632.756.522C19.851 20.979 23 16.854 23 12c0-6.077-4.922-11-11-11Z"></path>
+    </svg>
+  );
+}

frontend/src/components/workspace/input-box.tsx

@@ -0,0 +1,71 @@
+import type { ChatStatus } from "ai";
+import { useCallback, type ComponentProps } from "react";
+
+import {
+  PromptInput,
+  PromptInputBody,
+  PromptInputFooter,
+  PromptInputSubmit,
+  PromptInputTextarea,
+  type PromptInputMessage,
+} from "@/components/ai-elements/prompt-input";
+import { cn } from "@/lib/utils";
+
+export function InputBox({
+  className,
+  autoFocus,
+  status = "ready",
+  onSubmit,
+  onStop,
+  ...props
+}: Omit<ComponentProps<typeof PromptInput>, "onSubmit"> & {
+  assistantId?: string | null;
+  status?: ChatStatus;
+  onSubmit?: (message: PromptInputMessage) => void;
+  onStop?: () => void;
+}) {
+  const handleSubmit = useCallback(
+    async (message: PromptInputMessage) => {
+      if (status === "streaming") {
+        onStop?.();
+        return;
+      }
+      if (!message.text) {
+        return;
+      }
+      onSubmit?.(message);
+    },
+    [onSubmit, onStop, status],
+  );
+  return (
+    <PromptInput
+      className={cn(
+        "bg-background/50 rounded-2xl drop-shadow-2xl backdrop-blur-sm transition-all duration-300 ease-out *:data-[slot='input-group']:rounded-2xl",
+        "focus-within:bg-background/85 h-48 translate-y-14 overflow-hidden",
+        className,
+      )}
+      globalDrop
+      multiple
+      onSubmit={handleSubmit}
+      {...props}
+    >
+      <PromptInputBody>
+        <PromptInputTextarea
+          className={cn("size-full")}
+          placeholder="How can I assist you today?"
+          autoFocus={autoFocus}
+        />
+      </PromptInputBody>
+      <PromptInputFooter className="flex">
+        <div></div>
+        <div className="flex items-center gap-2">
+          <PromptInputSubmit
+            className="rounded-full"
+            variant="outline"
+            status={status}
+          />
+        </div>
+      </PromptInputFooter>
+    </PromptInput>
+  );
+}

frontend/src/components/workspace/message-list/index.ts

@@ -0,0 +1 @@
+export * from "./message-list";

frontend/src/components/workspace/message-list/message-group.tsx

@@ -0,0 +1,329 @@
+import type { Message } from "@langchain/langgraph-sdk";
+import {
+  BookOpenTextIcon,
+  FolderOpenIcon,
+  GlobeIcon,
+  LightbulbIcon,
+  ListTreeIcon,
+  NotebookPenIcon,
+  SearchIcon,
+  SquareTerminalIcon,
+  WrenchIcon,
+} from "lucide-react";
+import { useMemo, useState } from "react";
+
+import {
+  ChainOfThought,
+  ChainOfThoughtContent,
+  ChainOfThoughtHeader,
+  ChainOfThoughtSearchResult,
+  ChainOfThoughtSearchResults,
+  ChainOfThoughtStep,
+} from "@/components/ai-elements/chain-of-thought";
+import { MessageResponse } from "@/components/ai-elements/message";
+import { useRehypeSplitWordsIntoSpans } from "@/core/rehype";
+import { extractTitleFromMarkdown } from "@/core/utils/markdown";
+import { cn } from "@/lib/utils";
+
+import {
+  extractReasoningContentFromMessage,
+  findToolCallResult,
+} from "./utils";
+
+export function MessageGroup({
+  className,
+  messages,
+  isLoading = false,
+}: {
+  className?: string;
+  messages: Message[];
+  isLoading?: boolean;
+}) {
+  const steps = useMemo(() => convertToSteps(messages), [messages]);
+  const rehypePlugins = useRehypeSplitWordsIntoSpans(isLoading);
+  const [open, setOpen] = useState(false);
+  const lastStep = steps[steps.length - 1]!;
+  const { label, icon } = describeStep(lastStep);
+  return (
+    <ChainOfThought
+      className={cn("w-full rounded-lg border px-4 pt-4", className)}
+      defaultOpen={false}
+      open={open}
+      onOpenChange={setOpen}
+    >
+      <ChainOfThoughtHeader
+        className="min-h-6"
+        icon={
+          open && steps.length > 1 ? <ListTreeIcon className="size-4" /> : icon
+        }
+      >
+        <div className="flex w-full items-center justify-between">
+          <div>
+            <div>
+              {open && steps.length > 1 ? (
+                <div>{steps.length} steps</div>
+              ) : (
+                <MessageResponse rehypePlugins={rehypePlugins}>
+                  {label}
+                </MessageResponse>
+              )}
+            </div>
+          </div>
+          <div>
+            {!open && steps.length > 1 && (
+              <div className="tet-xs opacity-60">
+                {steps.length - 1} more step
+                {steps.length - 1 > 1 ? "s" : ""}
+              </div>
+            )}
+          </div>
+        </div>
+      </ChainOfThoughtHeader>
+      <ChainOfThoughtContent className="pb-4">
+        {steps.map((step) =>
+          step.type === "reasoning" ? (
+            <ChainOfThoughtStep
+              key={step.id}
+              label={
+                <MessageResponse rehypePlugins={rehypePlugins}>
+                  {step.reasoning ?? ""}
+                </MessageResponse>
+              }
+            />
+          ) : (
+            <ToolCall key={step.id} {...step} />
+          ),
+        )}
+      </ChainOfThoughtContent>
+    </ChainOfThought>
+  );
+}
+
+function ToolCall({
+  id,
+  name,
+  args,
+  result,
+}: {
+  id?: string;
+  name: string;
+  args: Record<string, unknown>;
+  result?: string | Record<string, unknown>;
+}) {
+  if (name === "web_search") {
+    let label: React.ReactNode = "Search for related information";
+    if (typeof args.query === "string") {
+      label = (
+        <div>
+          Search on the web for{" "}
+          <span className="font-bold">&quot;{args.query}&quot;</span>
+        </div>
+      );
+    }
+    return (
+      <ChainOfThoughtStep key={id} label={label} icon={SearchIcon}>
+        {Array.isArray(result) && (
+          <ChainOfThoughtSearchResults>
+            {result.map((item) => (
+              <ChainOfThoughtSearchResult key={item.url}>
+                <a href={item.url} target="_blank" rel="noreferrer">
+                  {item.title}
+                </a>
+              </ChainOfThoughtSearchResult>
+            ))}
+          </ChainOfThoughtSearchResults>
+        )}
+      </ChainOfThoughtStep>
+    );
+  } else if (name === "web_fetch") {
+    const url = (args as { url: string })?.url;
+    let title = url;
+    if (typeof result === "string") {
+      const potentialTitle = extractTitleFromMarkdown(result);
+      if (potentialTitle && potentialTitle.toLowerCase() !== "untitled") {
+        title = potentialTitle;
+      }
+    }
+    return (
+      <ChainOfThoughtStep key={id} label="View web page" icon={GlobeIcon}>
+        <ChainOfThoughtSearchResult>
+          {url && (
+            <a href={url} target="_blank" rel="noreferrer">
+              {title}
+            </a>
+          )}
+        </ChainOfThoughtSearchResult>
+      </ChainOfThoughtStep>
+    );
+  } else if (name === "ls") {
+    let description: string | undefined = (args as { description: string })
+      ?.description;
+    if (!description) {
+      description = "List folder";
+    }
+    const path: string | undefined = (args as { path: string })?.path;
+    return (
+      <ChainOfThoughtStep key={id} label={description} icon={FolderOpenIcon}>
+        {path && (
+          <ChainOfThoughtSearchResult>{path}</ChainOfThoughtSearchResult>
+        )}
+      </ChainOfThoughtStep>
+    );
+  } else if (name === "read_file") {
+    let description: string | undefined = (args as { description: string })
+      ?.description;
+    if (!description) {
+      description = "Read file";
+    }
+    const path: string | undefined = (args as { path: string })?.path;
+    return (
+      <ChainOfThoughtStep key={id} label={description} icon={BookOpenTextIcon}>
+        {path && (
+          <ChainOfThoughtSearchResult>{path}</ChainOfThoughtSearchResult>
+        )}
+      </ChainOfThoughtStep>
+    );
+  } else if (name === "write_file" || name === "str_replace") {
+    let description: string | undefined = (args as { description: string })
+      ?.description;
+    if (!description) {
+      description = "Write file";
+    }
+    const path: string | undefined = (args as { path: string })?.path;
+    return (
+      <ChainOfThoughtStep key={id} label={description} icon={NotebookPenIcon}>
+        {path && (
+          <ChainOfThoughtSearchResult>{path}</ChainOfThoughtSearchResult>
+        )}
+      </ChainOfThoughtStep>
+    );
+  } else if (name === "bash") {
+    const description: string | undefined = (args as { description: string })
+      ?.description;
+    if (!description) {
+      return "Execute command";
+    }
+    const command: string | undefined = (args as { command: string })?.command;
+    return (
+      <ChainOfThoughtStep
+        key={id}
+        label={description}
+        icon={SquareTerminalIcon}
+      >
+        {command && (
+          <ChainOfThoughtSearchResult>{command}</ChainOfThoughtSearchResult>
+        )}
+      </ChainOfThoughtStep>
+    );
+  } else {
+    const description: string | undefined = (args as { description: string })
+      ?.description;
+    return (
+      <ChainOfThoughtStep
+        key={id}
+        label={
+          description ?? (
+            <div>
+              Use tool <b>{name}</b>
+            </div>
+          )
+        }
+        icon={WrenchIcon}
+      ></ChainOfThoughtStep>
+    );
+  }
+}
+
+interface GenericCoTStep<T extends string = string> {
+  id?: string;
+  type: T;
+}
+
+interface CoTReasoningStep extends GenericCoTStep<"reasoning"> {
+  reasoning: string | null;
+}
+
+interface CoTToolCallStep extends GenericCoTStep<"toolCall"> {
+  name: string;
+  args: Record<string, unknown>;
+  result?: string;
+}
+
+type CoTStep = CoTReasoningStep | CoTToolCallStep;
+
+function convertToSteps(messages: Message[]): CoTStep[] {
+  const steps: CoTStep[] = [];
+  for (const message of messages) {
+    if (message.type === "ai") {
+      const reasoning = extractReasoningContentFromMessage(message);
+      if (reasoning) {
+        const step: CoTReasoningStep = {
+          id: message.id,
+          type: "reasoning",
+          reasoning: extractReasoningContentFromMessage(message),
+        };
+        steps.push(step);
+      }
+      for (const tool_call of message.tool_calls ?? []) {
+        const step: CoTToolCallStep = {
+          id: tool_call.id,
+          type: "toolCall",
+          name: tool_call.name,
+          args: tool_call.args,
+        };
+        const toolCallId = tool_call.id;
+        if (toolCallId) {
+          const toolCallResult = findToolCallResult(toolCallId, messages);
+          if (toolCallResult) {
+            try {
+              const json = JSON.parse(toolCallResult);
+              step.result = json;
+            } catch {
+              step.result = toolCallResult;
+            }
+          }
+        }
+        steps.push(step);
+      }
+    }
+  }
+  return steps;
+}
+
+function describeStep(step: CoTStep): {
+  label: string;
+  icon: React.ReactElement;
+} {
+  if (step.type === "reasoning") {
+    return { label: "Thinking", icon: <LightbulbIcon className="size-4" /> };
+  } else {
+    let label: string;
+    let icon: React.ReactElement = <WrenchIcon className="size-4" />;
+    if (step.name === "web_search") {
+      label = "Search on the web";
+      icon = <SearchIcon className="size-4" />;
+    } else if (step.name === "web_fetch") {
+      label = "View web page";
+      icon = <GlobeIcon className="size-4" />;
+    } else if (step.name === "ls") {
+      label = "List folder";
+      icon = <FolderOpenIcon className="size-4" />;
+    } else if (step.name === "read_file") {
+      label = "Read file";
+      icon = <BookOpenTextIcon className="size-4" />;
+    } else if (step.name === "write_file" || step.name === "str_replace") {
+      label = "Write file";
+      icon = <NotebookPenIcon className="size-4" />;
+    } else if (step.name === "bash") {
+      label = "Execute command";
+      icon = <SquareTerminalIcon className="size-4" />;
+    } else {
+      label = `Call tool "${step.name}"`;
+      icon = <WrenchIcon className="size-4" />;
+    }
+    if (typeof step.args.description === "string") {
+      label = step.args.description;
+    }
+    return { label, icon };
+  }
+}

frontend/src/components/workspace/message-list/message-list-item.tsx

@@ -0,0 +1,71 @@
+import type { Message } from "@langchain/langgraph-sdk";
+import { memo } from "react";
+
+import {
+  Message as AIElementMessage,
+  MessageContent as AIElementMessageContent,
+  MessageResponse as AIElementMessageResponse,
+} from "@/components/ai-elements/message";
+import { useRehypeSplitWordsIntoSpans } from "@/core/rehype";
+import { cn } from "@/lib/utils";
+
+import { MessageGroup } from "./message-group";
+import { extractContentFromMessage, hasReasoning, hasToolCalls } from "./utils";
+
+export function MessageListItem({
+  className,
+  message,
+  messagesInGroup,
+  isLoading,
+}: {
+  className?: string;
+  message: Message;
+  messagesInGroup: Message[];
+  isLoading?: boolean;
+}) {
+  return (
+    <AIElementMessage
+      className={cn("relative", "group/conversation-message", className)}
+      from={message.type === "human" ? "user" : "assistant"}
+    >
+      <MessageContent
+        className={className}
+        message={message}
+        messagesInGroup={messagesInGroup}
+        isLoading={isLoading}
+      />
+    </AIElementMessage>
+  );
+}
+
+function MessageContent_({
+  className,
+  message,
+  messagesInGroup,
+  isLoading = false,
+}: {
+  className?: string;
+  message: Message;
+  messagesInGroup: Message[];
+  isLoading?: boolean;
+}) {
+  const rehypePlugins = useRehypeSplitWordsIntoSpans(isLoading);
+  return (
+    <AIElementMessageContent className={className}>
+      {hasReasoning(message) && (
+        <MessageGroup
+          className="mb-2"
+          messages={[message]}
+          isLoading={isLoading}
+        />
+      )}
+      <AIElementMessageResponse rehypePlugins={rehypePlugins}>
+        {extractContentFromMessage(message)}
+      </AIElementMessageResponse>
+      {hasToolCalls(message) && (
+        <MessageGroup messages={messagesInGroup} isLoading={isLoading} />
+      )}
+    </AIElementMessageContent>
+  );
+}
+const MessageContent = memo(MessageContent_);

frontend/src/components/workspace/message-list/message-list.tsx

@@ -0,0 +1,63 @@
+import type { UseStream } from "@langchain/langgraph-sdk/react";
+
+import {
+  Conversation,
+  ConversationContent,
+  ConversationScrollButton,
+} from "@/components/ai-elements/conversation";
+import type { MessageThreadState } from "@/core/thread";
+import { cn } from "@/lib/utils";
+
+import { StreamingIndicator } from "../streaming-indicator";
+
+import { MessageGroup } from "./message-group";
+import { MessageListItem } from "./message-list-item";
+import { MessageListSkeleton } from "./skeleton";
+import { groupMessages, hasContent } from "./utils";
+
+export function MessageList({
+  className,
+  thread,
+}: {
+  className?: string;
+  thread: UseStream<MessageThreadState>;
+}) {
+  if (thread.isThreadLoading) {
+    return <MessageListSkeleton />;
+  }
+  return (
+    <Conversation
+      className={cn("flex size-full flex-col justify-center pt-2", className)}
+    >
+      <ConversationContent className="mx-auto w-full max-w-(--container-width-md)">
+        {groupMessages(
+          thread.messages,
+          (groupedMessages, groupIndex, isLastGroup) => {
+            if (groupedMessages[0] && hasContent(groupedMessages[0])) {
+              const message = groupedMessages[0];
+              return (
+                <MessageListItem
+                  key={message.id}
+                  message={message}
+                  messagesInGroup={groupedMessages}
+                  isLoading={thread.isLoading}
+                />
+              );
+            }
+            return (
+              <MessageGroup
+                key={groupedMessages[0]!.id}
+                messages={groupedMessages}
+                isLoading={thread.isLoading}
+              />
+            );
+          },
+          thread.isLoading,
+        )}
+        {thread.isLoading && <StreamingIndicator className="my-4" />}
+        <div className="h-40" />
+      </ConversationContent>
+      <ConversationScrollButton className="-translate-y-16 backdrop-blur-xs" />
+    </Conversation>
+  );
+}

frontend/src/components/workspace/message-list/skeleton.tsx

@@ -0,0 +1,4 @@
+export function MessageListSkeleton() {
+  // TODO: Add a loading state
+  return null;
+}

frontend/src/components/workspace/message-list/utils.ts

@@ -0,0 +1,157 @@
+import type { Message } from "@langchain/langgraph-sdk";
+
+export function groupMessages<T>(
+  messages: Message[],
+  mapper: (
+    groupedMessages: Message[],
+    groupIndex: number,
+    isLastGroup: boolean,
+  ) => T,
+  isLoading = false,
+): T[] {
+  if (messages.length === 0) {
+    return [];
+  }
+  const resultsOfGroups: T[] = [];
+  let currentGroup: Message[] = [];
+  const lastMessage = messages[messages.length - 1]!;
+  const yieldCurrentGroup = () => {
+    if (currentGroup.length > 0) {
+      const resultOfGroup = mapper(
+        currentGroup,
+        resultsOfGroups.length,
+        currentGroup.includes(lastMessage),
+      );
+      if (resultOfGroup !== undefined && resultOfGroup !== null) {
+        resultsOfGroups.push(resultOfGroup);
+      }
+      currentGroup = [];
+    }
+  };
+  let messageIndex = 0;
+  for (const message of messages) {
+    if (message.type === "human") {
+      // Human messages are always shown as a individual group
+      yieldCurrentGroup();
+      currentGroup.push(message);
+      yieldCurrentGroup();
+    } else if (message.type === "tool") {
+      // Tool messages are always shown with the assistant messages that contains the tool calls
+      currentGroup.push(message);
+    } else if (message.type === "ai") {
+      if (
+        hasToolCalls(message) ||
+        (extractTextFromMessage(message) === "" &&
+          extractReasoningContentFromMessage(message) !== "" &&
+          messageIndex === messages.length - 1 &&
+          isLoading)
+      ) {
+        // Assistant messages without any content are folded into the previous group
+        // Normally, these are tool calls (with or without thinking)
+        currentGroup.push(message);
+      } else {
+        // Assistant messages with content (text or images) are shown as a group if they have content
+        // No matter whether it has tool calls or not
+        yieldCurrentGroup();
+        currentGroup.push(message);
+      }
+    }
+    messageIndex++;
+  }
+  yieldCurrentGroup();
+  return resultsOfGroups;
+}
+
+export function extractTextFromMessage(message: Message) {
+  if (typeof message.content === "string") {
+    return message.content.trim();
+  }
+  if (Array.isArray(message.content)) {
+    return message.content
+      .map((content) => (content.type === "text" ? content.text : ""))
+      .join("\n")
+      .trim();
+  }
+  return "";
+}
+
+export function extractContentFromMessage(message: Message) {
+  if (typeof message.content === "string") {
+    return message.content.trim();
+  }
+  if (Array.isArray(message.content)) {
+    return message.content
+      .map((content) => {
+        switch (content.type) {
+          case "text":
+            return content.text;
+          case "image_url":
+            const imageURL = extractURLFromImageURLContent(content.image_url);
+            return `![image](${imageURL})`;
+          default:
+            return "";
+        }
+      })
+      .join("\n")
+      .trim();
+  }
+  return "";
+}
+
+export function extractReasoningContentFromMessage(message: Message) {
+  if (message.type !== "ai" || !message.additional_kwargs) {
+    return null;
+  }
+  if ("reasoning_content" in message.additional_kwargs) {
+    return message.additional_kwargs.reasoning_content as string | null;
+  }
+  return null;
+}
+
+export function extractURLFromImageURLContent(
+  content:
+    | string
+    | {
+        url: string;
+      },
+) {
+  if (typeof content === "string") {
+    return content;
+  }
+  return content.url;
+}
+
+export function hasContent(message: Message) {
+  if (typeof message.content === "string") {
+    return message.content.trim().length > 0;
+  }
+  if (Array.isArray(message.content)) {
+    return message.content.length > 0;
+  }
+  return false;
+}
+
+export function hasReasoning(message: Message) {
+  return (
+    message.type === "ai" &&
+    typeof message.additional_kwargs?.reasoning_content === "string"
+  );
+}
+
+export function hasToolCalls(message: Message) {
+  return (
+    message.type === "ai" && message.tool_calls && message.tool_calls.length > 0
+  );
+}
+
+export function findToolCallResult(toolCallId: string, messages: Message[]) {
+  for (const message of messages) {
+    if (message.type === "tool" && message.tool_call_id === toolCallId) {
+      const content = extractTextFromMessage(message);
+      if (content) {
+        return content;
+      }
+    }
+  }
+  return undefined;
+}

frontend/src/components/workspace/overscroll.tsx

@@ -0,0 +1,17 @@
+"use client";
+
+import { useEffect } from "react";
+
+export function Overscroll({
+  behavior,
+  overflow = "hidden",
+}: {
+  behavior: "none" | "contain" | "auto";
+  overflow?: "hidden" | "auto" | "scroll";
+}) {
+  useEffect(() => {
+    document.documentElement.style.overflow = overflow;
+    document.documentElement.style.overscrollBehavior = behavior;
+  }, [behavior, overflow]);
+  return null;
+}

frontend/src/components/workspace/recent-chat-list.tsx

@@ -0,0 +1,107 @@
+"use client";
+
+import { MoreHorizontal, Trash2 } from "lucide-react";
+import Link from "next/link";
+import { useParams, usePathname, useRouter } from "next/navigation";
+import { useCallback } from "react";
+
+import {
+  DropdownMenu,
+  DropdownMenuContent,
+  DropdownMenuItem,
+  DropdownMenuTrigger,
+} from "@/components/ui/dropdown-menu";
+import {
+  SidebarGroup,
+  SidebarGroupContent,
+  SidebarGroupLabel,
+  SidebarMenu,
+  SidebarMenuAction,
+  SidebarMenuButton,
+  SidebarMenuItem,
+} from "@/components/ui/sidebar";
+import { useDeleteThread, useThreads } from "@/core/api";
+import { pathOfThread, titleOfThread } from "@/core/thread/utils";
+
+export function RecentChatList() {
+  const router = useRouter();
+  const pathname = usePathname();
+  const { thread_id: threadIdFromPath } = useParams<{ thread_id: string }>();
+  const { data: threads = [] } = useThreads();
+  const { mutate: deleteThread } = useDeleteThread();
+  const handleDelete = useCallback(
+    (threadId: string) => {
+      deleteThread({ threadId });
+      if (threadId === threadIdFromPath) {
+        const threadIndex = threads.findIndex((t) => t.thread_id === threadId);
+        let nextThreadId = "new";
+        if (threadIndex > -1) {
+          if (threads[threadIndex + 1]) {
+            nextThreadId = threads[threadIndex + 1]!.thread_id;
+          } else if (threads[threadIndex - 1]) {
+            nextThreadId = threads[threadIndex - 1]!.thread_id;
+          }
+        }
+        void router.push(`/workspace/chats/${nextThreadId}`);
+      }
+    },
+    [deleteThread, router, threadIdFromPath, threads],
+  );
+  if (threads.length === 0) {
+    return null;
+  }
+  return (
+    <SidebarGroup>
+      <SidebarGroupLabel>Recents</SidebarGroupLabel>
+      <SidebarGroupContent className="group-data-[collapsible=icon]:pointer-events-none group-data-[collapsible=icon]:-mt-8 group-data-[collapsible=icon]:opacity-0">
+        <SidebarMenu>
+          <div className="flex w-full flex-col gap-1">
+            {threads.map((thread) => {
+              const isActive = pathOfThread(thread, false) === pathname;
+              return (
+                <SidebarMenuItem
+                  key={thread.thread_id}
+                  className="group/side-menu-item"
+                >
+                  <SidebarMenuButton isActive={isActive} asChild>
+                    <div>
+                      <Link
+                        className="text-muted-foreground block w-full whitespace-nowrap group-hover/side-menu-item:overflow-hidden"
+                        href={pathOfThread(thread)}
+                      >
+                        {titleOfThread(thread)}
+                      </Link>
+                      <DropdownMenu>
+                        <DropdownMenuTrigger asChild>
+                          <SidebarMenuAction
+                            showOnHover
+                            className="bg-background/50 hover:bg-background"
+                          >
+                            <MoreHorizontal />
+                            <span className="sr-only">More</span>
+                          </SidebarMenuAction>
+                        </DropdownMenuTrigger>
+                        <DropdownMenuContent
+                          className="w-48 rounded-lg"
+                          side={"right"}
+                          align={"start"}
+                        >
+                          <DropdownMenuItem
+                            onSelect={() => handleDelete(thread.thread_id)}
+                          >
+                            <Trash2 className="text-muted-foreground" />
+                            <span>Delete</span>
+                          </DropdownMenuItem>
+                        </DropdownMenuContent>
+                      </DropdownMenu>
+                    </div>
+                  </SidebarMenuButton>
+                </SidebarMenuItem>
+              );
+            })}
+          </div>
+        </SidebarMenu>
+      </SidebarGroupContent>
+    </SidebarGroup>
+  );
+}

frontend/src/components/workspace/streaming-indicator.tsx

@@ -0,0 +1,34 @@
+import { cn } from "@/lib/utils";
+
+export function StreamingIndicator({
+  className,
+  size = "normal",
+}: {
+  className?: string;
+  size?: "normal" | "sm";
+}) {
+  const dotSize = size === "sm" ? "w-1.5 h-1.5 mx-0.5" : "w-2 h-2 mx-1";
+
+  return (
+    <div className={cn("flex", className)}>
+      <div
+        className={cn(
+          dotSize,
+          "animate-bouncing rounded-full bg-[#a3a1a1] opacity-100",
+        )}
+      />
+      <div
+        className={cn(
+          dotSize,
+          "animate-bouncing rounded-full bg-[#a3a1a1] opacity-100 [animation-delay:0.2s]",
+        )}
+      />
+      <div
+        className={cn(
+          dotSize,
+          "animate-bouncing rounded-full bg-[#a3a1a1] opacity-100 [animation-delay:0.4s]",
+        )}
+      />
+    </div>
+  );
+}

frontend/src/components/workspace/tooltip.tsx

@@ -0,0 +1,23 @@
+"use client";
+
+import {
+  Tooltip as TooltipPrimitive,
+  TooltipContent,
+  TooltipTrigger,
+} from "@/components/ui/tooltip";
+
+export function Tooltip({
+  children,
+  content,
+  ...props
+}: {
+  children: React.ReactNode;
+  content?: React.ReactNode;
+}) {
+  return (
+    <TooltipPrimitive {...props}>
+      <TooltipTrigger asChild>{children}</TooltipTrigger>
+      <TooltipContent className="shadow">{content}</TooltipContent>
+    </TooltipPrimitive>
+  );
+}

frontend/src/components/workspace/workspace-container.tsx

@@ -0,0 +1,146 @@
+"use client";
+
+import Link from "next/link";
+import { usePathname } from "next/navigation";
+import { useMemo } from "react";
+
+import {
+  Breadcrumb,
+  BreadcrumbItem,
+  BreadcrumbLink,
+  BreadcrumbList,
+  BreadcrumbPage,
+  BreadcrumbSeparator,
+} from "@/components/ui/breadcrumb";
+import { cn } from "@/lib/utils";
+
+import { GithubIcon } from "./github-icon";
+import { Tooltip } from "./tooltip";
+
+export function WorkspaceContainer({
+  className,
+  children,
+  ...props
+}: React.ComponentProps<"div">) {
+  return (
+    <div className={cn("flex h-screen w-full flex-col", className)} {...props}>
+      {children}
+    </div>
+  );
+}
+
+export function WorkspaceHeader({
+  className,
+  children,
+  ...props
+}: React.ComponentProps<"header">) {
+  const pathname = usePathname();
+  const segments = useMemo(() => {
+    const parts = pathname?.split("/") || [];
+    if (parts.length > 0) {
+      return parts.slice(1, 3);
+    }
+  }, [pathname]);
+  return (
+    <header
+      className={cn(
+        "top-0 right-0 left-0 z-20 flex h-16 shrink-0 items-center justify-between gap-2 border-b backdrop-blur-sm transition-[width,height] ease-out group-has-data-[collapsible=icon]/sidebar-wrapper:h-12",
+        className,
+      )}
+      {...props}
+    >
+      <div className="flex items-center gap-2 px-4">
+        <Breadcrumb>
+          <BreadcrumbList>
+            {segments?.[0] && (
+              <BreadcrumbItem className="hidden md:block">
+                <BreadcrumbLink asChild>
+                  <Link href={`/${segments[0]}`}>
+                    {nameOfSegment(segments[0])}
+                  </Link>
+                </BreadcrumbLink>
+              </BreadcrumbItem>
+            )}
+            {segments?.[1] && (
+              <>
+                <BreadcrumbSeparator className="hidden md:block" />
+                <BreadcrumbItem>
+                  {segments.length >= 2 ? (
+                    <BreadcrumbLink asChild>
+                      <Link href={`/${segments[0]}/${segments[1]}`}>
+                        {nameOfSegment(segments[1])}
+                      </Link>
+                    </BreadcrumbLink>
+                  ) : (
+                    <BreadcrumbPage>
+                      {nameOfSegment(segments[1])}
+                    </BreadcrumbPage>
+                  )}
+                </BreadcrumbItem>
+              </>
+            )}
+            {children && (
+              <>
+                <BreadcrumbSeparator />
+                {children}
+              </>
+            )}
+          </BreadcrumbList>
+        </Breadcrumb>
+      </div>
+      <div className="pr-4">
+        <Tooltip content="DeerFlow on Github">
+          <a
+            href="https://github.com/bytedance/deer-flow"
+            target="_blank"
+            rel="noopener noreferrer"
+            className="opacity-75 transition hover:opacity-100"
+          >
+            <GithubIcon className="size-6" />
+          </a>
+        </Tooltip>
+      </div>
+    </header>
+  );
+}
+
+export function WorkspaceBody({
+  className,
+  children,
+  ...props
+}: React.ComponentProps<"main">) {
+  return (
+    <main
+      className={cn(
+        "relative flex min-h-0 w-full flex-1 flex-col items-center",
+        className,
+      )}
+      {...props}
+    >
+      <div className="flex h-full w-full flex-col items-center">{children}</div>
+    </main>
+  );
+}
+
+export function WorkspaceFooter({
+  className,
+  children,
+  ...props
+}: React.ComponentProps<"footer">) {
+  return (
+    <footer
+      className={cn(
+        "absolute right-0 bottom-0 left-0 z-30 flex justify-center",
+        className,
+      )}
+      {...props}
+    >
+      {children}
+    </footer>
+  );
+}
+
+function nameOfSegment(segment: string | undefined) {
+  if (!segment) return "Home";
+  return segment[0]?.toUpperCase() + segment.slice(1);
+}

frontend/src/components/workspace/workspace-header.tsx

@@ -0,0 +1,30 @@
+"use client";
+
+import { SidebarTrigger, useSidebar } from "@/components/ui/sidebar";
+import { cn } from "@/lib/utils";
+
+export function WorkspaceHeader({ className }: { className?: string }) {
+  const { state } = useSidebar();
+  return (
+    <div
+      className={cn(
+        "group/workspace-header flex h-15 flex-col justify-center",
+        className,
+      )}
+    >
+      {state === "collapsed" ? (
+        <div className="flex w-full cursor-pointer items-center justify-center group-has-data-[collapsible=icon]/sidebar-wrapper:-translate-y-[6px]">
+          <h1 className="text-primary block font-serif group-hover/workspace-header:hidden">
+            DF
+          </h1>
+          <SidebarTrigger className="hidden pl-2 group-hover/workspace-header:block" />
+        </div>
+      ) : (
+        <div className="flex items-center justify-between gap-2">
+          <h1 className="text-primary ml-2 font-serif">DeerFlow</h1>
+          <SidebarTrigger />
+        </div>
+      )}
+    </div>
+  );
+}

frontend/src/components/workspace/workspace-nav-menu.tsx

@@ -0,0 +1,41 @@
+"use client";
+
+import { MessageSquarePlus, MessagesSquare } from "lucide-react";
+import Link from "next/link";
+import { usePathname } from "next/navigation";
+
+import {
+  SidebarGroup,
+  SidebarMenu,
+  SidebarMenuButton,
+  SidebarMenuItem,
+} from "@/components/ui/sidebar";
+
+export function WorkspaceNavMenu() {
+  const pathname = usePathname();
+  return (
+    <SidebarGroup>
+      <SidebarMenu>
+        <SidebarMenuItem>
+          <SidebarMenuButton
+            isActive={pathname === "/workspace/chats/new"}
+            asChild
+          >
+            <Link className="text-muted-foreground" href="/workspace/chats/new">
+              <MessageSquarePlus size={16} />
+              <span>New chat</span>
+            </Link>
+          </SidebarMenuButton>
+        </SidebarMenuItem>
+        <SidebarMenuItem>
+          <SidebarMenuButton isActive={pathname === "/workspace/chats"} asChild>
+            <Link className="text-muted-foreground" href="/workspace/chats">
+              <MessagesSquare />
+              <span>Chats</span>
+            </Link>
+          </SidebarMenuButton>
+        </SidebarMenuItem>
+      </SidebarMenu>
+    </SidebarGroup>
+  );
+}

frontend/src/components/workspace/workspace-sidebar.tsx

@@ -0,0 +1,29 @@
+import {
+  Sidebar,
+  SidebarHeader,
+  SidebarContent,
+  SidebarFooter,
+  SidebarRail,
+} from "@/components/ui/sidebar";
+
+import { RecentChatList } from "./recent-chat-list";
+import { WorkspaceHeader } from "./workspace-header";
+import { WorkspaceNavMenu } from "./workspace-nav-menu";
+
+export function WorkspaceSidebar({
+  ...props
+}: React.ComponentProps<typeof Sidebar>) {
+  return (
+    <Sidebar variant="sidebar" collapsible="icon" {...props}>
+      <SidebarHeader className="py-0">
+        <WorkspaceHeader />
+      </SidebarHeader>
+      <SidebarContent>
+        <WorkspaceNavMenu />
+        <RecentChatList />
+      </SidebarContent>
+      <SidebarFooter></SidebarFooter>
+      <SidebarRail />
+    </Sidebar>
+  );
+}

frontend/src/core/api/client.ts

@@ -0,0 +1,17 @@
+"use client";
+
+import { Client as LangGraphClient } from "@langchain/langgraph-sdk/client";
+
+let _singleton: LangGraphClient | null = null;
+export function getLangGraphClient(): LangGraphClient {
+  let url: URL | null = null;
+  if (typeof window === "undefined") {
+    url = new URL("/api/langgraph", "http://localhost:3000");
+  } else {
+    url = new URL("/api/langgraph", window.location.origin);
+  }
+  _singleton ??= new LangGraphClient({
+    apiUrl: "http://localhost:2024",
+  });
+  return _singleton;
+}

frontend/src/core/api/hooks.ts

@@ -0,0 +1,45 @@
+import type { ThreadsClient } from "@langchain/langgraph-sdk/client";
+import { useMutation, useQuery, useQueryClient } from "@tanstack/react-query";
+
+import type { MessageThread, MessageThreadState } from "../thread";
+
+import { getLangGraphClient } from "./client";
+
+export function useThreads(
+  params: Parameters<ThreadsClient["search"]>[0] = {
+    limit: 50,
+    sortBy: "updated_at",
+    sortOrder: "desc",
+  },
+) {
+  const langGraphClient = getLangGraphClient();
+  return useQuery<MessageThread[]>({
+    queryKey: ["threads", "search", params],
+    queryFn: async () => {
+      const response =
+        await langGraphClient.threads.search<MessageThreadState>(params);
+      return response as MessageThread[];
+    },
+  });
+}
+
+export function useDeleteThread() {
+  const queryClient = useQueryClient();
+  const langGraphClient = getLangGraphClient();
+  return useMutation({
+    mutationFn: async ({ threadId }: { threadId: string }) => {
+      await langGraphClient.threads.delete(threadId);
+    },
+    onSuccess(_, { threadId }) {
+      queryClient.setQueriesData(
+        {
+          queryKey: ["threads", "search"],
+          exact: false,
+        },
+        (oldData: Array<MessageThread>) => {
+          return oldData.filter((t) => t.thread_id !== threadId);
+        },
+      );
+    },
+  });
+}

frontend/src/core/api/index.ts

@@ -0,0 +1,2 @@
+export * from "./client";
+export * from "./hooks";

frontend/src/core/rehype/index.ts

@@ -0,0 +1,49 @@
+import type { Element, Root, ElementContent } from "hast";
+import { useMemo } from "react";
+import { visit } from "unist-util-visit";
+import type { BuildVisitor } from "unist-util-visit";
+
+export function rehypeSplitWordsIntoSpans() {
+  return (tree: Root) => {
+    visit(tree, "element", ((node: Element) => {
+      if (
+        ["p", "h1", "h2", "h3", "h4", "h5", "h6", "li", "strong"].includes(
+          node.tagName,
+        ) &&
+        node.children
+      ) {
+        const newChildren: Array<ElementContent> = [];
+        node.children.forEach((child) => {
+          if (child.type === "text") {
+            const segmenter = new Intl.Segmenter("zh", { granularity: "word" });
+            const segments = segmenter.segment(child.value);
+            const words = Array.from(segments)
+              .map((segment) => segment.segment)
+              .filter(Boolean);
+            words.forEach((word: string) => {
+              newChildren.push({
+                type: "element",
+                tagName: "span",
+                properties: {
+                  className: "animate-fade-in",
+                },
+                children: [{ type: "text", value: word }],
+              });
+            });
+          } else {
+            newChildren.push(child);
+          }
+        });
+        node.children = newChildren;
+      }
+    }) as BuildVisitor<Root, "element">);
+  };
+}
+
+export function useRehypeSplitWordsIntoSpans(enabled = true) {
+  const rehypePlugins = useMemo(
+    () => (enabled ? [rehypeSplitWordsIntoSpans] : []),
+    [enabled],
+  );
+  return rehypePlugins;
+}

frontend/src/core/thread/index.ts

@@ -0,0 +1 @@
+export * from "./types";

frontend/src/core/thread/types.ts

@@ -0,0 +1,8 @@
+import { type BaseMessage } from "@langchain/core/messages";
+import type { Thread } from "@langchain/langgraph-sdk";
+
+export interface MessageThreadState extends Record<string, unknown> {
+  messages: BaseMessage[];
+}
+
+export interface MessageThread extends Thread<MessageThreadState> {}

frontend/src/core/thread/utils.ts

@@ -0,0 +1,27 @@
+import type { BaseMessage } from "@langchain/core/messages";
+
+import type { MessageThread } from "./types";
+
+export function pathOfThread(thread: MessageThread, includeAssistantId = true) {
+  if (includeAssistantId) {
+    return `/workspace/chats/${thread.thread_id}`;
+  }
+  return `/workspace/chats/${thread.thread_id}`;
+}
+
+export function textOfMessage(message: BaseMessage) {
+  if (typeof message.content === "string") {
+    return message.content;
+  } else if (Array.isArray(message.content)) {
+    return message.content.find((part) => part.type === "text" && part.text)
+      ?.text as string;
+  }
+  return null;
+}
+
+export function titleOfThread(thread: MessageThread) {
+  if (thread.values && "title" in thread.values) {
+    return thread.values.title as string;
+  }
+  return "Untitled";
+}

frontend/src/core/utils/json.ts

@@ -0,0 +1,10 @@
+import { parse } from "best-effort-json-parser";
+
+export function tryParseJSON(json: string) {
+  try {
+    const object = parse(json);
+    return object;
+  } catch {
+    return undefined;
+  }
+}

frontend/src/core/utils/markdown.ts

@@ -0,0 +1,10 @@
+export function extractTitleFromMarkdown(markdown: string) {
+  if (markdown.startsWith("# ")) {
+    let title = markdown.split("\n")[0]!.trim();
+    if (title.startsWith("# ")) {
+      title = title.slice(2).trim();
+    }
+    return title;
+  }
+  return undefined;
+}

frontend/src/core/utils/uuid.ts

@@ -0,0 +1 @@
+export { v4 as uuid } from "uuid";

frontend/src/hooks/use-mobile.ts

@@ -0,0 +1,19 @@
+import * as React from "react"
+
+const MOBILE_BREAKPOINT = 768
+
+export function useIsMobile() {
+  const [isMobile, setIsMobile] = React.useState<boolean | undefined>(undefined)
+
+  React.useEffect(() => {
+    const mql = window.matchMedia(`(max-width: ${MOBILE_BREAKPOINT - 1}px)`)
+    const onChange = () => {
+      setIsMobile(window.innerWidth < MOBILE_BREAKPOINT)
+    }
+    mql.addEventListener("change", onChange)
+    setIsMobile(window.innerWidth < MOBILE_BREAKPOINT)
+    return () => mql.removeEventListener("change", onChange)
+  }, [])
+
+  return !!isMobile
+}

frontend/src/styles/globals.css

@@ -1,11 +1,97 @@
 @import "tailwindcss";
 @import "tw-animate-css";
 
+@source "../node_modules/streamdown/dist/index.js";
+
+/* Heading */
+@source inline("text-{xs,sm,base,lg,xl,2xl,3xl,4xl,5xl,6xl}");
+@source inline("font-{normal,medium,semibold,bold,extrabold}");
+@source inline("leading-{none,tight,snug,normal,relaxed,loose}");
+
+/* Spacing */
+@source inline("m{t,b,l,r,x,y}-{0,1,2,3,4,5,6,8,10,12,16,20,24}");
+@source inline("p{t,b,l,r,x,y}-{0,1,2,3,4,5,6,8,10,12,16,20,24}");
+@source inline("space-{x,y}-{1,2,3,4,5,6,8}");
+
+/* List */
+@source inline("list-{disc,decimal,none,inside,outside}");
+
+/* Text */
+@source inline("text-{left,center,right,justify}");
+@source inline("text-{slate,gray,zinc,neutral,stone}-{50,100,200,300,400,500,600,700,800,900,950}");
+@source inline("italic");
+@source inline("underline");
+@source inline("line-through");
+
+/* Code */
+@source inline("font-mono");
+@source inline("bg-{slate,gray,zinc,muted}-{50,100,200}");
+@source inline("rounded{,-sm,-md,-lg,-xl}");
+@source inline("border{,-2,-4}");
+@source inline("border-{slate,gray,zinc,border}-{200,300}");
+
+/* Blockquote */
+@source inline("border-l-{2,4}");
+@source inline("border-l-{slate,gray,primary}-{300,400,500}");
+
+/* Link */
+@source inline("text-{blue,primary,accent}-{500,600,700}");
+@source inline("hover:text-{blue,primary,accent}-{600,700,800}");
+@source inline("hover:underline");
+
+/* Table */
+@source inline("border-collapse");
+@source inline("table-auto");
+@source inline("w-full");
+@source inline("divide-{x,y}");
+@source inline("divide-{slate,gray,border}-{200,300}");
+
+/* Image */
+@source inline("max-w-{xs,sm,md,lg,xl,2xl,full}");
+@source inline("h-auto");
+@source inline("object-cover");
+
+/* Horizontal Rule */
+@source inline("border-t");
+@source inline("border-{slate,gray,border}-{200,300}");
+
+/* General */
+@source inline("block");
+@source inline("inline");
+@source inline("inline-block");
+@source inline("break-words");
+@source inline("overflow-{auto,hidden,x-auto}");
+@source inline("whitespace-pre-wrap");
+
+/* Shadcn Colors */
+@source inline("text-{foreground,muted-foreground,primary,secondary,accent}");
+@source inline("bg-{background,muted,primary,secondary,accent}");
+@source inline("border-{border,input}");
+
 @custom-variant dark (&:is(.dark *));
 
 @theme {
-  --font-sans: var(--font-geist-sans), ui-sans-serif, system-ui, sans-serif,
+  --font-sans:
+    var(--font-geist-sans), ui-sans-serif, system-ui, sans-serif,
     "Apple Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol", "Noto Color Emoji";
+
+  --animate-fade-in: fade-in 1.1s;
+  @keyframes fade-in {
+    0% {
+      opacity: 0;
+    }
+    100% {
+      opacity: 1;
+    }
+  }
+
+  --animate-bouncing: bouncing 0.5s infinite alternate;
+  @keyframes bouncing {
+    to {
+      opacity: 0.1;
+      transform: translateY(-8px);
+    }
+  }
 }
 
 @theme inline {
@@ -116,6 +202,7 @@
   --sidebar-accent-foreground: oklch(0.985 0 0);
   --sidebar-border: oklch(1 0 0 / 10%);
   --sidebar-ring: oklch(0.556 0 0);
+  font-weight: 300;
 }
 
 @layer base {
@@ -126,3 +213,10 @@
     @apply bg-background text-foreground;
   }
 }
+
+:root {
+  --container-width-xs: calc(var(--spacing) * 72);
+  --container-width-sm: calc(var(--spacing) * 144);
+  --container-width-md: calc(var(--spacing) * 204);
+  --container-width-lg: calc(var(--spacing) * 256);
+}

frontend/tsconfig.json

@@ -22,7 +22,7 @@
     "noEmit": true,
     "module": "ESNext",
     "moduleResolution": "Bundler",
-    "jsx": "react-jsx",
+    "jsx": "preserve",
     "plugins": [
       {
         "name": "next"