feat(webui): polish chat layout and titles

Align the WebUI sidebar and chat chrome with the updated design, and generate WebUI session titles asynchronously without blocking turns. Co-authored-by: Cursor <cursoragent@cursor.com>
2026-05-19 16:12:30 +00:00 · 2026-05-06 14:15:36 +00:00 · 2026-05-06 14:15:36 +00:00 · 790a03ec28
commit 790a03ec28
parent d8fd4c80bf
33 changed files with 1270 additions and 312 deletions
--- a/nanobot/agent/loop.py
+++ b/nanobot/agent/loop.py
@ -55,6 +55,7 @@ from nanobot.utils.progress_events import (
    on_progress_accepts_tool_events,
 )
 from nanobot.utils.runtime import EMPTY_FINAL_RESPONSE_MESSAGE
+from nanobot.utils.webui_titles import mark_webui_session, maybe_generate_webui_title_after_turn

 if TYPE_CHECKING:
    from nanobot.config.schema import ChannelsConfig, ExecToolConfig, ToolsConfig, WebToolsConfig
@ -814,6 +815,25 @@ class AgentLoop:
                            channel=msg.channel, chat_id=msg.chat_id,
                            content="", metadata={**msg.metadata, "_turn_end": True},
                        ))
+                        if msg.metadata.get("webui") is True:
+                            async def _generate_title_and_notify() -> None:
+                                generated = await maybe_generate_webui_title_after_turn(
+                                    channel=msg.channel,
+                                    metadata=msg.metadata,
+                                    sessions=self.sessions,
+                                    session_key=session_key,
+                                    provider=self.provider,
+                                    model=self.model,
+                                )
+                                if generated:
+                                    await self.bus.publish_outbound(OutboundMessage(
+                                        channel=msg.channel,
+                                        chat_id=msg.chat_id,
+                                        content="",
+                                        metadata={**msg.metadata, "_session_updated": True},
+                                    ))
+
+                            self._schedule_background(_generate_title_and_notify())
                except asyncio.CancelledError:
                    logger.info("Task cancelled for session {}", session_key)
                    # Preserve partial context from the interrupted turn so
@ -1003,6 +1023,7 @@ class AgentLoop:

        key = session_key or msg.session_key
        session = self.sessions.get_or_create(key)
+        mark_webui_session(session, msg.metadata)
        if self._restore_runtime_checkpoint(session):
            self.sessions.save(session)
        if self._restore_pending_user_turn(session):
--- a/nanobot/channels/websocket.py
+++ b/nanobot/channels/websocket.py
@ -1184,12 +1184,15 @@ class WebSocketChannel(BaseChannel):

            # Auto-attach on first use so clients can one-shot without a separate attach.
            self._attach(connection, cid)
+            metadata: dict[str, Any] = {"remote": getattr(connection, "remote_address", None)}
+            if envelope.get("webui") is True:
+                metadata["webui"] = True
            await self._handle_message(
                sender_id=client_id,
                chat_id=cid,
                content=content,
                media=media_paths or None,
-                metadata={"remote": getattr(connection, "remote_address", None)},
+                metadata=metadata,
            )
            return
        await self._send_event(connection, "error", detail=f"unknown type: {t!r}")
@ -1233,6 +1236,9 @@ class WebSocketChannel(BaseChannel):
        if msg.metadata.get("_turn_end"):
            await self.send_turn_end(msg.chat_id)
            return
+        if msg.metadata.get("_session_updated"):
+            await self.send_session_updated(msg.chat_id)
+            return
        text = msg.content
        if msg.buttons:
            text = _append_buttons_as_text(text, msg.buttons)
@ -1299,3 +1305,13 @@ class WebSocketChannel(BaseChannel):
        raw = json.dumps(body, ensure_ascii=False)
        for connection in conns:
            await self._safe_send_to(connection, raw, label=" turn_end ")
+
+    async def send_session_updated(self, chat_id: str) -> None:
+        """Notify clients that session metadata changed outside the main turn."""
+        conns = list(self._subs.get(chat_id, ()))
+        if not conns:
+            return
+        body: dict[str, Any] = {"event": "session_updated", "chat_id": chat_id}
+        raw = json.dumps(body, ensure_ascii=False)
+        for connection in conns:
+            await self._safe_send_to(connection, raw, label=" session_updated ")
--- a/nanobot/session/manager.py
+++ b/nanobot/session/manager.py
@ -547,10 +547,13 @@ class SessionManager:
                        data = json.loads(first_line)
                        if data.get("_type") == "metadata":
                            key = data.get("key") or path.stem.replace("_", ":", 1)
+                            metadata = data.get("metadata", {})
+                            title = metadata.get("title") if isinstance(metadata, dict) else None
                            sessions.append({
                                "key": key,
                                "created_at": data.get("created_at"),
                                "updated_at": data.get("updated_at"),
+                                "title": title if isinstance(title, str) else "",
                                "path": str(path)
                            })
            except Exception:
@ -560,6 +563,11 @@ class SessionManager:
                        "key": repaired.key,
                        "created_at": repaired.created_at.isoformat(),
                        "updated_at": repaired.updated_at.isoformat(),
+                        "title": (
+                            repaired.metadata.get("title")
+                            if isinstance(repaired.metadata.get("title"), str)
+                            else ""
+                        ),
                        "path": str(path)
                    })
                continue
--- a/nanobot/utils/webui_titles.py
+++ b/nanobot/utils/webui_titles.py
@ -0,0 +1,138 @@
+"""Helpers for WebUI chat title generation."""
+
+from __future__ import annotations
+
+import re
+from typing import Any
+
+from loguru import logger
+
+from nanobot.providers.base import LLMProvider
+from nanobot.session.manager import Session, SessionManager
+from nanobot.utils.helpers import truncate_text
+
+WEBUI_SESSION_METADATA_KEY = "webui"
+WEBUI_TITLE_METADATA_KEY = "title"
+WEBUI_TITLE_USER_EDITED_METADATA_KEY = "title_user_edited"
+TITLE_MAX_CHARS = 60
+
+
+def mark_webui_session(session: Session, metadata: dict[str, Any]) -> bool:
+    """Persist a WebUI marker only when the inbound websocket frame opted in."""
+    if metadata.get(WEBUI_SESSION_METADATA_KEY) is not True:
+        return False
+    session.metadata[WEBUI_SESSION_METADATA_KEY] = True
+    return True
+
+
+def clean_generated_title(raw: str | None) -> str:
+    text = (raw or "").strip()
+    if not text:
+        return ""
+    text = re.sub(r"^\s*(title|标题)\s*[:：]\s*", "", text, flags=re.IGNORECASE)
+    text = text.strip().strip("\"'`“”‘’")
+    text = re.sub(r"\s+", " ", text).strip()
+    text = text.rstrip("。.!！?？,，;；:")
+    if len(text) > TITLE_MAX_CHARS:
+        text = text[: TITLE_MAX_CHARS - 1].rstrip() + "…"
+    return text
+
+
+def _title_inputs(session: Session) -> tuple[str, str]:
+    user_text = ""
+    assistant_text = ""
+    for message in session.messages:
+        role = message.get("role")
+        content = message.get("content")
+        if not isinstance(content, str) or not content.strip():
+            continue
+        if role == "user" and not user_text:
+            user_text = content.strip()
+        elif role == "assistant" and not assistant_text:
+            assistant_text = content.strip()
+        if user_text and assistant_text:
+            break
+    return user_text, assistant_text
+
+
+async def maybe_generate_webui_title(
+    *,
+    sessions: SessionManager,
+    session_key: str,
+    provider: LLMProvider,
+    model: str,
+) -> bool:
+    """Generate and persist a short title for WebUI-owned sessions only."""
+    session = sessions.get_or_create(session_key)
+    if session.metadata.get(WEBUI_SESSION_METADATA_KEY) is not True:
+        return False
+    if session.metadata.get(WEBUI_TITLE_USER_EDITED_METADATA_KEY) is True:
+        return False
+    current_title = session.metadata.get(WEBUI_TITLE_METADATA_KEY)
+    if isinstance(current_title, str) and current_title.strip():
+        return False
+
+    user_text, assistant_text = _title_inputs(session)
+    if not user_text:
+        return False
+
+    prompt = (
+        "Generate a concise title for this chat.\n"
+        "Rules:\n"
+        "- Use the same language as the user when practical.\n"
+        "- 3 to 8 words.\n"
+        "- No quotes.\n"
+        "- No punctuation at the end.\n"
+        "- Return only the title.\n\n"
+        f"User: {truncate_text(user_text, 1_000)}"
+    )
+    if assistant_text:
+        prompt += f"\nAssistant: {truncate_text(assistant_text, 1_000)}"
+
+    try:
+        response = await provider.chat_with_retry(
+            [
+                {
+                    "role": "system",
+                    "content": (
+                        "You write short, neutral chat titles. "
+                        "Return only the title text."
+                    ),
+                },
+                {"role": "user", "content": prompt},
+            ],
+            tools=None,
+            model=model,
+            max_tokens=32,
+            temperature=0.2,
+            retry_mode="standard",
+        )
+    except Exception:
+        logger.debug("Failed to generate webui session title for {}", session_key, exc_info=True)
+        return False
+
+    title = clean_generated_title(response.content)
+    if not title or title.lower().startswith("error"):
+        return False
+    session.metadata[WEBUI_TITLE_METADATA_KEY] = title
+    sessions.save(session)
+    return True
+
+
+async def maybe_generate_webui_title_after_turn(
+    *,
+    channel: str,
+    metadata: dict[str, Any],
+    sessions: SessionManager,
+    session_key: str,
+    provider: LLMProvider,
+    model: str,
+) -> bool:
+    if channel != "websocket" or metadata.get(WEBUI_SESSION_METADATA_KEY) is not True:
+        return False
+    return await maybe_generate_webui_title(
+        sessions=sessions,
+        session_key=session_key,
+        provider=provider,
+        model=model,
+    )
--- a/tests/agent/test_loop_progress.py
+++ b/tests/agent/test_loop_progress.py
@ -1,5 +1,6 @@
 """Tests for structured tool-event progress metadata emitted by AgentLoop."""

+import asyncio
 from pathlib import Path
 from unittest.mock import AsyncMock, MagicMock

@ -291,6 +292,48 @@ class TestToolEventProgress:
        assert (outbound[-1].metadata or {}).get("_turn_end") is True
        assert outbound[-1].chat_id == "chat1"

+    @pytest.mark.asyncio
+    async def test_webui_title_generation_runs_after_turn_end(self, tmp_path: Path) -> None:
+        bus = MessageBus()
+        provider = MagicMock()
+        provider.get_default_model.return_value = "test-model"
+        title_started = asyncio.Event()
+        release_title = asyncio.Event()
+        calls = 0
+
+        async def chat_with_retry(*_args: object, **_kwargs: object) -> LLMResponse:
+            nonlocal calls
+            calls += 1
+            if calls == 1:
+                return LLMResponse(content="Done", tool_calls=[])
+            title_started.set()
+            await release_title.wait()
+            return LLMResponse(content="Generated title", tool_calls=[])
+
+        provider.chat_with_retry = AsyncMock(side_effect=chat_with_retry)
+        loop = AgentLoop(bus=bus, provider=provider, workspace=tmp_path, model="test-model")
+        loop.tools.get_definitions = MagicMock(return_value=[])
+        loop.consolidator.maybe_consolidate_by_tokens = AsyncMock(return_value=False)  # type: ignore[method-assign]
+
+        await asyncio.wait_for(loop._dispatch(InboundMessage(
+            channel="websocket",
+            sender_id="u1",
+            chat_id="chat1",
+            content="say hello",
+            metadata={"webui": True},
+        )), timeout=0.5)
+
+        outbound = [await bus.consume_outbound(), await bus.consume_outbound()]
+        assert outbound[0].content == "Done"
+        assert (outbound[1].metadata or {}).get("_turn_end") is True
+
+        await asyncio.wait_for(title_started.wait(), timeout=0.5)
+        release_title.set()
+        session_updated = await asyncio.wait_for(bus.consume_outbound(), timeout=0.5)
+
+        assert (session_updated.metadata or {}).get("_session_updated") is True
+        assert provider.chat_with_retry.await_count == 2
+
    @pytest.mark.asyncio
    async def test_non_websocket_dispatch_does_not_publish_turn_end_marker(self, tmp_path: Path) -> None:
        bus = MessageBus()
--- a/tests/agent/test_loop_save_turn.py
+++ b/tests/agent/test_loop_save_turn.py
@ -8,7 +8,13 @@ from nanobot.agent.context import ContextBuilder
 from nanobot.agent.loop import AgentLoop
 from nanobot.bus.events import InboundMessage
 from nanobot.bus.queue import MessageBus
+from nanobot.providers.base import LLMResponse
 from nanobot.session.manager import Session
+from nanobot.utils.webui_titles import (
+    WEBUI_SESSION_METADATA_KEY,
+    WEBUI_TITLE_METADATA_KEY,
+    maybe_generate_webui_title,
+)


 def _mk_loop() -> AgentLoop:
@ -22,9 +28,56 @@ def _mk_loop() -> AgentLoop:
 def _make_full_loop(tmp_path: Path) -> AgentLoop:
    provider = MagicMock()
    provider.get_default_model.return_value = "test-model"
+    provider.chat_with_retry = AsyncMock(return_value=LLMResponse(content="Test title"))
    return AgentLoop(bus=MessageBus(), provider=provider, workspace=tmp_path, model="test-model")


+@pytest.mark.asyncio
+async def test_generate_webui_title_only_for_marked_webui_sessions(tmp_path: Path) -> None:
+    loop = _make_full_loop(tmp_path)
+    loop.provider.chat_with_retry = AsyncMock(
+        return_value=LLMResponse(content='"优化 WebUI 侧边栏。"', finish_reason="stop")
+    )
+    session = loop.sessions.get_or_create("websocket:chat-title")
+    session.metadata[WEBUI_SESSION_METADATA_KEY] = True
+    session.add_message("user", "帮我优化一下 webui 的 sidebar")
+    session.add_message("assistant", "可以，我会先调整布局和视觉层级。")
+    loop.sessions.save(session)
+
+    generated = await maybe_generate_webui_title(
+        sessions=loop.sessions,
+        session_key="websocket:chat-title",
+        provider=loop.provider,
+        model=loop.model,
+    )
+
+    assert generated is True
+    assert session.metadata[WEBUI_TITLE_METADATA_KEY] == "优化 WebUI 侧边栏"
+    loop.provider.chat_with_retry.assert_awaited_once()
+
+
+@pytest.mark.asyncio
+async def test_generate_webui_title_skips_plain_websocket_sessions(tmp_path: Path) -> None:
+    loop = _make_full_loop(tmp_path)
+    loop.provider.chat_with_retry = AsyncMock(
+        return_value=LLMResponse(content="Plain websocket title", finish_reason="stop")
+    )
+    session = loop.sessions.get_or_create("websocket:custom-client")
+    session.add_message("user", "hello from a custom websocket client")
+    loop.sessions.save(session)
+
+    generated = await maybe_generate_webui_title(
+        sessions=loop.sessions,
+        session_key="websocket:custom-client",
+        provider=loop.provider,
+        model=loop.model,
+    )
+
+    assert generated is False
+    assert WEBUI_TITLE_METADATA_KEY not in session.metadata
+    loop.provider.chat_with_retry.assert_not_awaited()
+
+
 def test_save_turn_skips_multimodal_user_when_only_runtime_context() -> None:
    loop = _mk_loop()
    session = Session(key="test:runtime-only")
--- a/tests/agent/test_session_manager_history.py
+++ b/tests/agent/test_session_manager_history.py
@ -1,4 +1,4 @@
-from nanobot.session.manager import Session
+from nanobot.session.manager import Session, SessionManager


 def _assert_no_orphans(history: list[dict]) -> None:
@ -31,6 +31,18 @@ def _tool_turn(prefix: str, idx: int) -> list[dict]:
    ]


+def test_list_sessions_includes_metadata_title(tmp_path):
+    manager = SessionManager(tmp_path)
+    session = manager.get_or_create("websocket:chat-title")
+    session.metadata["title"] = "自动生成标题"
+    manager.save(session)
+
+    rows = manager.list_sessions()
+
+    assert rows[0]["key"] == "websocket:chat-title"
+    assert rows[0]["title"] == "自动生成标题"
+
+
 # --- Original regression test (from PR 2075) ---

 def test_get_history_drops_orphan_tool_results_when_window_cuts_tool_calls():
--- a/tests/channels/test_websocket_channel.py
+++ b/tests/channels/test_websocket_channel.py
@ -167,6 +167,40 @@ def test_issue_route_secret_matches_empty_secret() -> None:
    assert _issue_route_secret_matches(Headers([("Authorization", "Bearer anything")]), "") is True


+@pytest.mark.asyncio
+async def test_webui_message_envelope_marks_inbound_metadata(bus: MagicMock) -> None:
+    channel = _ch(bus)
+    conn = MagicMock()
+    conn.remote_address = ("127.0.0.1", 50123)
+
+    await channel._dispatch_envelope(
+        conn,
+        "webui-client",
+        {"type": "message", "chat_id": "chat-1", "content": "hello", "webui": True},
+    )
+
+    msg = bus.publish_inbound.await_args.args[0]
+    assert msg.channel == "websocket"
+    assert msg.chat_id == "chat-1"
+    assert msg.metadata["webui"] is True
+    assert msg.metadata["_wants_stream"] is True
+
+
+@pytest.mark.asyncio
+async def test_plain_websocket_message_does_not_mark_webui(bus: MagicMock) -> None:
+    channel = _ch(bus)
+    conn = MagicMock()
+
+    await channel._dispatch_envelope(
+        conn,
+        "custom-client",
+        {"type": "message", "chat_id": "chat-1", "content": "hello"},
+    )
+
+    msg = bus.publish_inbound.await_args.args[0]
+    assert "webui" not in msg.metadata
+
+
@pytest.mark.asyncio
 async def test_send_delivers_json_message_with_media_and_reply() -> None:
    bus = MagicMock()
@ -306,6 +340,25 @@ async def test_send_turn_end_emits_turn_end_event() -> None:
    assert body == {"event": "turn_end", "chat_id": "chat-1"}


+@pytest.mark.asyncio
+async def test_send_session_updated_emits_session_updated_event() -> None:
+    bus = MagicMock()
+    channel = WebSocketChannel({"enabled": True, "allowFrom": ["*"]}, bus)
+    mock_ws = AsyncMock()
+    channel._attach(mock_ws, "chat-1")
+
+    await channel.send(OutboundMessage(
+        channel="websocket",
+        chat_id="chat-1",
+        content="",
+        metadata={"_session_updated": True},
+    ))
+
+    mock_ws.send.assert_awaited_once()
+    body = json.loads(mock_ws.send.await_args.args[0])
+    assert body == {"event": "session_updated", "chat_id": "chat-1"}
+
+
@pytest.mark.asyncio
 async def test_send_non_connection_closed_exception_is_raised() -> None:
    bus = MagicMock()
--- a/webui/src/App.tsx
+++ b/webui/src/App.tsx
@ -25,7 +25,7 @@ type BootState =
    };

 const SIDEBAR_STORAGE_KEY = "nanobot-webui.sidebar";
-const SIDEBAR_WIDTH = 279;
+const SIDEBAR_WIDTH = 272;
 type ShellView = "chat" | "settings";

 function readSidebarOpen(): boolean {
@ -99,13 +99,6 @@ export default function App() {
    return (
      <div className="flex h-full w-full items-center justify-center">
        <div className="flex flex-col items-center gap-3 animate-in fade-in-0 duration-300">
-          <img
-            src="/brand/nanobot_icon.png"
-            alt=""
-            className="h-10 w-10 animate-pulse select-none"
-            aria-hidden
-            draggable={false}
-          />
          <div className="flex items-center gap-2 text-sm text-muted-foreground">
            <span className="relative flex h-2 w-2">
              <span className="absolute inline-flex h-full w-full animate-ping rounded-full bg-foreground/40" />
@ -121,13 +114,6 @@ export default function App() {
    return (
      <div className="flex h-full w-full items-center justify-center px-4 text-center">
        <div className="flex max-w-md flex-col items-center gap-3">
-          <img
-            src="/brand/nanobot_icon.png"
-            alt=""
-            className="h-10 w-10 opacity-60 grayscale select-none"
-            aria-hidden
-            draggable={false}
-          />
          <p className="text-lg font-semibold">{t("app.error.title")}</p>
          <p className="text-sm text-muted-foreground">{state.message}</p>
          <p className="text-xs text-muted-foreground">
@ -213,7 +199,7 @@ function Shell({ onModelNameChange }: { onModelNameChange: (modelName: string |
    }
  }, []);

-  const onNewChat = useCallback(async () => {
+  const onCreateChat = useCallback(async () => {
    try {
      const chatId = await createChat();
      setActiveKey(`websocket:${chatId}`);
@ -226,6 +212,12 @@ function Shell({ onModelNameChange }: { onModelNameChange: (modelName: string |
    }
  }, [createChat]);

+  const onNewChat = useCallback(() => {
+    setActiveKey(null);
+    setView("chat");
+    setMobileSidebarOpen(false);
+  }, []);
+
  const onSelectChat = useCallback(
    (key: string) => {
      setActiveKey(key);
@ -235,6 +227,15 @@ function Shell({ onModelNameChange }: { onModelNameChange: (modelName: string |
    [],
  );

+  const onOpenSettings = useCallback(() => {
+    setView("settings");
+    setMobileSidebarOpen(false);
+  }, []);
+
+  const onTurnEnd = useCallback(() => {
+    void refresh();
+  }, [refresh]);
+
  const onConfirmDelete = useCallback(async () => {
    if (!pendingDelete) return;
    const key = pendingDelete.key;
@ -254,7 +255,8 @@ function Shell({ onModelNameChange }: { onModelNameChange: (modelName: string |
  }, [pendingDelete, deleteChat, activeKey, sessions]);

  const headerTitle = activeSession
-    ? activeSession.preview ||
+    ? activeSession.title ||
+      activeSession.preview ||
      t("chat.fallbackTitle", { id: activeSession.chatId.slice(0, 6) })
    : t("app.brand");

@ -268,20 +270,10 @@ function Shell({ onModelNameChange }: { onModelNameChange: (modelName: string |
    sessions,
    activeKey,
    loading,
-    theme,
-    onToggleTheme: toggle,
-    onNewChat: () => {
-      void onNewChat();
-    },
+    onNewChat,
    onSelect: onSelectChat,
-    onRefresh: () => void refresh(),
    onRequestDelete: (key: string, label: string) =>
      setPendingDelete({ key, label }),
-    activeView: view,
-    onOpenSettings: () => {
-      setView("settings" as const);
-      setMobileSidebarOpen(false);
-    },
  };

  return (
@ -296,10 +288,11 @@ function Shell({ onModelNameChange }: { onModelNameChange: (modelName: string |
      >
        <div
          className={cn(
-            "absolute inset-y-0 left-0 h-full w-[279px] overflow-hidden bg-sidebar shadow-inner-right",
+            "absolute inset-y-0 left-0 h-full overflow-hidden bg-sidebar shadow-inner-right",
            "transition-transform duration-300 ease-out",
            desktopSidebarOpen ? "translate-x-0" : "-translate-x-full",
          )}
+          style={{ width: SIDEBAR_WIDTH }}
        >
          <Sidebar {...sidebarProps} onCollapse={closeDesktopSidebar} />
        </div>
@ -312,7 +305,8 @@ function Shell({ onModelNameChange }: { onModelNameChange: (modelName: string |
        <SheetContent
          side="left"
          showCloseButton={false}
-          className="w-[279px] p-0 sm:max-w-[279px] lg:hidden"
+          className="p-0 lg:hidden"
+          style={{ width: SIDEBAR_WIDTH, maxWidth: SIDEBAR_WIDTH }}
        >
          <Sidebar {...sidebarProps} onCollapse={closeMobileSidebar} />
        </SheetContent>
@ -331,8 +325,12 @@ function Shell({ onModelNameChange }: { onModelNameChange: (modelName: string |
            session={activeSession}
            title={headerTitle}
            onToggleSidebar={toggleSidebar}
-            onGoHome={() => setActiveKey(null)}
            onNewChat={onNewChat}
+            onCreateChat={onCreateChat}
+            onTurnEnd={onTurnEnd}
+            theme={theme}
+            onToggleTheme={toggle}
+            onOpenSettings={onOpenSettings}
            hideSidebarToggleOnDesktop={desktopSidebarOpen}
          />
        )}
--- a/webui/src/components/ChatList.tsx
+++ b/webui/src/components/ChatList.tsx
@ -8,7 +8,6 @@ import {
  DropdownMenuTrigger,
 } from "@/components/ui/dropdown-menu";
 import { ScrollArea } from "@/components/ui/scroll-area";
-import { relativeTime } from "@/lib/format";
 import { cn } from "@/lib/utils";
 import type { ChatSummary } from "@/lib/types";

@ -18,10 +17,11 @@ interface ChatListProps {
  onSelect: (key: string) => void;
  onRequestDelete: (key: string, label: string) => void;
  loading?: boolean;
+  emptyLabel?: string;
 }

 function titleFor(s: ChatSummary, fallbackTitle: string): string {
-  const p = s.preview?.trim();
+  const p = (s.title || s.preview)?.trim();
  if (p) return p.length > 48 ? `${p.slice(0, 45)}…` : p;
  return fallbackTitle;
 }
@ -32,6 +32,7 @@ export function ChatList({
  onSelect,
  onRequestDelete,
  loading,
+  emptyLabel,
 }: ChatListProps) {
  const { t } = useTranslation();
  if (loading && sessions.length === 0) {
@ -44,73 +45,111 @@ export function ChatList({

  if (sessions.length === 0) {
    return (
-      <div className="px-3 py-6 text-xs text-muted-foreground">
-        {t("chat.noSessions")}
+      <div className="px-3 py-6 text-[12px] leading-5 text-muted-foreground/80">
+        {emptyLabel ?? t("chat.noSessions")}
      </div>
    );
  }

+  const groups = groupSessions(sessions, {
+    today: t("chat.groups.today"),
+    yesterday: t("chat.groups.yesterday"),
+    earlier: t("chat.groups.earlier"),
+  });
+
  return (
    <ScrollArea className="h-full">
-      <ul className="space-y-0.5 px-2 py-1">
-        {sessions.map((s) => {
-          const active = s.key === activeKey;
-          const title = titleFor(
-            s,
-            t("chat.fallbackTitle", { id: s.chatId.slice(0, 6) }),
-          );
-          return (
-            <li key={s.key}>
-              <div
-                className={cn(
-                  "group flex items-center gap-2 rounded-md px-2 py-1.5 text-[12.5px] transition-colors",
-                  active
-                    ? "bg-sidebar-accent/80 text-sidebar-accent-foreground shadow-[inset_0_0_0_1px_hsl(var(--border)/0.4)]"
-                    : "text-sidebar-foreground/88 hover:bg-sidebar-accent/45",
-                )}
-              >
-                <button
-                  type="button"
-                  onClick={() => onSelect(s.key)}
-                  className="flex min-w-0 flex-1 flex-col items-start text-left"
-                >
-                  <span className="w-full truncate font-medium leading-5">{title}</span>
-                  <span className="text-[10.5px] text-muted-foreground/80">
-                    {relativeTime(s.updatedAt ?? s.createdAt) || "—"}
-                  </span>
-                </button>
-                <DropdownMenu modal={false}>
-                  <DropdownMenuTrigger
-                    className={cn(
-                      "inline-flex h-6 w-6 items-center justify-center rounded-md text-muted-foreground opacity-0 transition-opacity",
-                      "hover:bg-sidebar-accent hover:text-sidebar-foreground group-hover:opacity-100",
-                      "focus-visible:opacity-100",
-                      active && "opacity-100",
-                    )}
-                    aria-label={t("chat.actions", { title })}
-                  >
-                    <MoreHorizontal className="h-4 w-4" />
-                  </DropdownMenuTrigger>
-                  <DropdownMenuContent
-                    align="end"
-                    onCloseAutoFocus={(event) => event.preventDefault()}
-                  >
-                    <DropdownMenuItem
-                      onSelect={() => {
-                        window.setTimeout(() => onRequestDelete(s.key, title), 0);
-                      }}
-                      className="text-destructive focus:text-destructive"
+      <div className="space-y-3 px-2 py-1.5">
+        {groups.map((group) => (
+          <section key={group.label} aria-label={group.label}>
+            <div className="px-2 pb-1 text-[12px] font-medium text-muted-foreground/65">
+              {group.label}
+            </div>
+            <ul className="space-y-0.5">
+              {group.sessions.map((s) => {
+                const active = s.key === activeKey;
+                const title = titleFor(
+                  s,
+                  t("chat.fallbackTitle", { id: s.chatId.slice(0, 6) }),
+                );
+                return (
+                  <li key={s.key}>
+                    <div
+                      className={cn(
+                        "group flex min-h-8 items-center gap-2 rounded-xl px-2 text-[13px] transition-colors",
+                        active
+                          ? "bg-sidebar-accent/70 text-sidebar-accent-foreground shadow-[inset_0_0_0_1px_hsl(var(--sidebar-border)/0.28)]"
+                          : "text-sidebar-foreground/82 hover:bg-sidebar-accent/50 hover:text-sidebar-foreground",
+                      )}
                    >
-                      <Trash2 className="mr-2 h-4 w-4" />
-                      {t("chat.delete")}
-                    </DropdownMenuItem>
-                  </DropdownMenuContent>
-                </DropdownMenu>
-              </div>
-            </li>
-          );
-        })}
-      </ul>
+                      <button
+                        type="button"
+                        onClick={() => onSelect(s.key)}
+                        className="min-w-0 flex-1 py-1.5 text-left"
+                      >
+                        <span className="block w-full truncate font-medium leading-5">{title}</span>
+                      </button>
+                      <DropdownMenu modal={false}>
+                        <DropdownMenuTrigger
+                          className={cn(
+                            "inline-flex h-6 w-6 items-center justify-center rounded-md text-muted-foreground/75 opacity-0 transition-opacity",
+                            "hover:bg-sidebar-accent hover:text-sidebar-foreground group-hover:opacity-100",
+                            "focus-visible:opacity-100",
+                            active && "opacity-100",
+                          )}
+                          aria-label={t("chat.actions", { title })}
+                        >
+                          <MoreHorizontal className="h-3.5 w-3.5" />
+                        </DropdownMenuTrigger>
+                        <DropdownMenuContent
+                          align="end"
+                          onCloseAutoFocus={(event) => event.preventDefault()}
+                        >
+                          <DropdownMenuItem
+                            onSelect={() => {
+                              window.setTimeout(() => onRequestDelete(s.key, title), 0);
+                            }}
+                            className="text-destructive focus:text-destructive"
+                          >
+                            <Trash2 className="mr-2 h-4 w-4" />
+                            {t("chat.delete")}
+                          </DropdownMenuItem>
+                        </DropdownMenuContent>
+                      </DropdownMenu>
+                    </div>
+                  </li>
+                );
+              })}
+            </ul>
+          </section>
+        ))}
+      </div>
    </ScrollArea>
  );
 }
+
+function groupSessions(
+  sessions: ChatSummary[],
+  labels: { today: string; yesterday: string; earlier: string },
+): Array<{ label: string; sessions: ChatSummary[] }> {
+  const now = new Date();
+  const startOfToday = new Date(now.getFullYear(), now.getMonth(), now.getDate()).getTime();
+  const startOfYesterday = startOfToday - 24 * 60 * 60 * 1000;
+  const buckets = new Map<string, ChatSummary[]>();
+
+  for (const session of sessions) {
+    const timestamp = Date.parse(session.updatedAt ?? session.createdAt ?? "");
+    const label = Number.isFinite(timestamp) && timestamp >= startOfToday
+      ? labels.today
+      : Number.isFinite(timestamp) && timestamp >= startOfYesterday
+        ? labels.yesterday
+        : labels.earlier;
+    const bucket = buckets.get(label) ?? [];
+    bucket.push(session);
+    buckets.set(label, bucket);
+  }
+
+  return [labels.today, labels.yesterday, labels.earlier]
+    .map((label) => ({ label, sessions: buckets.get(label) ?? [] }))
+    .filter((group) => group.sessions.length > 0);
+}
--- a/webui/src/components/ChatPane.tsx
+++ b/webui/src/components/ChatPane.tsx
@ -79,20 +79,8 @@ export function ChatPane({ session, onNewChat }: ChatPaneProps) {
      <section className="flex min-h-0 flex-1 flex-col">
        <div className="flex flex-1 flex-col items-center justify-center gap-8 px-4 pb-6">
          <div className="flex flex-col items-center gap-4 animate-in fade-in-0 slide-in-from-bottom-2 duration-500">
-            <picture>
-              <source
-                srcSet="/brand/nanobot_logo.webp"
-                type="image/webp"
-              />
-              <img
-                src="/brand/nanobot_logo.png"
-                alt="nanobot"
-                className="h-12 w-auto select-none drop-shadow-sm"
-                draggable={false}
-              />
-            </picture>
            <h1 className="text-xl font-medium tracking-tight text-foreground/90">
-              What's on your mind?
+              What can I do for you?
            </h1>
            <p className="max-w-md text-center text-sm text-muted-foreground">
              Your conversations are persisted locally under the nanobot
@ -105,7 +93,7 @@ export function ChatPane({ session, onNewChat }: ChatPaneProps) {
              disabled={booting}
              onSend={handleWelcomeSend}
              placeholder={
-                booting ? "Opening a new chat…" : "Type your message…"
+                booting ? "Opening a new chat…" : "Ask anything..."
              }
            />
          </div>
--- a/webui/src/components/ConnectionBadge.tsx
+++ b/webui/src/components/ConnectionBadge.tsx
@ -6,21 +6,21 @@ import { useClient } from "@/providers/ClientProvider";
 import type { ConnectionStatus } from "@/lib/types";

 const COPY: Record<ConnectionStatus, { color: string }> = {
-  idle: { color: "bg-card/40 text-muted-foreground" },
+  idle: { color: "text-muted-foreground" },
  connecting: {
-    color: "bg-amber-500/10 text-amber-700 dark:text-amber-300",
+    color: "text-amber-700 dark:text-amber-300",
  },
  open: {
-    color: "bg-emerald-500/10 text-emerald-700 dark:text-emerald-400",
+    color: "text-emerald-700 dark:text-emerald-400",
  },
  reconnecting: {
-    color: "bg-amber-500/10 text-amber-700 dark:text-amber-300",
+    color: "text-amber-700 dark:text-amber-300",
  },
  closed: {
-    color: "bg-card/40 text-muted-foreground",
+    color: "text-muted-foreground",
  },
  error: {
-    color: "bg-destructive/10 text-destructive",
+    color: "text-destructive",
  },
 };

@ -39,7 +39,7 @@ export function ConnectionBadge() {
  return (
    <span
      className={cn(
-        "inline-flex items-center gap-1.5 rounded-md border border-border/60 px-2 py-1 text-[11px] font-medium transition-colors",
+        "inline-flex min-w-0 items-center gap-1.5 rounded-md px-1.5 py-1 text-[11px] font-medium transition-colors",
        meta.color,
      )}
      aria-live="polite"
--- a/webui/src/components/MessageBubble.tsx
+++ b/webui/src/components/MessageBubble.tsx
@ -1,5 +1,5 @@
-import { useState } from "react";
-import { ChevronRight, FileIcon, ImageIcon, PlaySquare, Wrench } from "lucide-react";
+import { useCallback, useEffect, useRef, useState } from "react";
+import { Check, ChevronRight, Copy, FileIcon, ImageIcon, PlaySquare, Wrench } from "lucide-react";
 import { useTranslation } from "react-i18next";

 import { ImageLightbox } from "@/components/ImageLightbox";
@ -21,8 +21,33 @@ interface MessageBubbleProps {
 * collapsible group so intermediate steps never masquerade as replies.
 */
 export function MessageBubble({ message }: MessageBubbleProps) {
+  const { t } = useTranslation();
+  const [copied, setCopied] = useState(false);
+  const copyResetRef = useRef<number | null>(null);
  const baseAnim = "animate-in fade-in-0 slide-in-from-bottom-1 duration-300";

+  useEffect(() => {
+    return () => {
+      if (copyResetRef.current !== null) {
+        window.clearTimeout(copyResetRef.current);
+      }
+    };
+  }, []);
+
+  const onCopyAssistantReply = useCallback(() => {
+    if (!navigator.clipboard) return;
+    void navigator.clipboard.writeText(message.content).then(() => {
+      setCopied(true);
+      if (copyResetRef.current !== null) {
+        window.clearTimeout(copyResetRef.current);
+      }
+      copyResetRef.current = window.setTimeout(() => {
+        setCopied(false);
+        copyResetRef.current = null;
+      }, 1_500);
+    });
+  }, [message.content]);
+
  if (message.kind === "trace") {
    return <TraceGroup message={message} animClass={baseAnim} />;
  }
@ -60,6 +85,7 @@ export function MessageBubble({ message }: MessageBubbleProps) {

  const empty = message.content.trim().length === 0;
  const media = message.media ?? [];
+  const showAssistantActions = message.role === "assistant" && !message.isStreaming && !empty;
  return (
    <div className={cn("w-full text-sm", baseAnim)} style={{ lineHeight: "var(--cjk-line-height)" }}>
      {empty && message.isStreaming ? (
@ -69,6 +95,27 @@ export function MessageBubble({ message }: MessageBubbleProps) {
          <MarkdownText>{message.content}</MarkdownText>
          {message.isStreaming && <StreamCursor />}
          {media.length > 0 ? <MessageMedia media={media} align="left" /> : null}
+          {showAssistantActions ? (
+            <div className="mt-2 flex items-center gap-1 text-muted-foreground">
+              <button
+                type="button"
+                onClick={onCopyAssistantReply}
+                aria-label={copied ? t("message.copiedReply") : t("message.copyReply")}
+                title={copied ? t("message.copiedReply") : t("message.copyReply")}
+                className={cn(
+                  "inline-flex h-8 w-8 items-center justify-center rounded-full",
+                  "transition-colors hover:bg-muted/55 hover:text-foreground",
+                  "focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-ring",
+                )}
+              >
+                {copied ? (
+                  <Check className="h-4 w-4" aria-hidden />
+                ) : (
+                  <Copy className="h-4 w-4" aria-hidden />
+                )}
+              </button>
+            </div>
+          ) : null}
        </>
      )}
    </div>
--- a/webui/src/components/Sidebar.tsx
+++ b/webui/src/components/Sidebar.tsx
@ -1,109 +1,121 @@
-import { Moon, PanelLeftClose, RefreshCcw, Settings, SquarePen, Sun } from "lucide-react";
+import { useMemo, useState } from "react";
+import {
+  PanelLeftClose,
+  Search,
+  SquarePen,
+} from "lucide-react";
 import { useTranslation } from "react-i18next";

 import { ChatList } from "@/components/ChatList";
 import { ConnectionBadge } from "@/components/ConnectionBadge";
 import { Button } from "@/components/ui/button";
 import { Separator } from "@/components/ui/separator";
+import { cn } from "@/lib/utils";
 import type { ChatSummary } from "@/lib/types";

 interface SidebarProps {
  sessions: ChatSummary[];
  activeKey: string | null;
  loading: boolean;
-  theme: "light" | "dark";
-  onToggleTheme: () => void;
  onNewChat: () => void;
  onSelect: (key: string) => void;
-  onRefresh: () => void;
  onRequestDelete: (key: string, label: string) => void;
  onCollapse: () => void;
-  activeView?: "chat" | "settings";
-  onOpenSettings: () => void;
 }

 export function Sidebar(props: SidebarProps) {
  const { t } = useTranslation();
+  const [query, setQuery] = useState("");
+  const normalizedQuery = query.trim().toLowerCase();
+  const filteredSessions = useMemo(() => {
+    if (!normalizedQuery) return props.sessions;
+    return props.sessions.filter((session) => {
+      const haystack = [
+        session.preview,
+        session.chatId,
+        session.channel,
+        session.key,
+      ]
+        .filter(Boolean)
+        .join(" ")
+        .toLowerCase();
+      return haystack.includes(normalizedQuery);
+    });
+  }, [normalizedQuery, props.sessions]);
+
  return (
-    <aside className="flex h-full w-full flex-col border-r border-sidebar-border/70 bg-sidebar text-sidebar-foreground">
-      <div className="flex items-center justify-between px-3 pb-2 pt-3">
+    <nav
+      aria-label={t("sidebar.navigation")}
+      className="flex h-full w-full flex-col border-r border-sidebar-border/60 bg-sidebar text-sidebar-foreground"
+    >
+      <div className="flex items-center justify-between px-3 pb-2.5 pt-3">
        <picture className="block min-w-0">
          <source srcSet="/brand/nanobot_logo.webp" type="image/webp" />
          <img
            src="/brand/nanobot_logo.png"
            alt="nanobot"
-            className="h-7 w-auto select-none object-contain"
+            className="h-6 w-auto select-none object-contain opacity-95"
            draggable={false}
          />
        </picture>
-        <div className="flex items-center gap-0.5">
-          <Button
-            variant="ghost"
-            size="icon"
-            aria-label={t("sidebar.toggleTheme")}
-            onClick={props.onToggleTheme}
-            className="h-7 w-7 rounded-lg text-muted-foreground hover:bg-sidebar-accent hover:text-sidebar-foreground"
-          >
-            {props.theme === "dark" ? (
-              <Sun className="h-3.5 w-3.5" />
-            ) : (
-              <Moon className="h-3.5 w-3.5" />
-            )}
-          </Button>
-          <Button
-            variant="ghost"
-            size="icon"
-            aria-label={t("sidebar.collapse")}
-            onClick={props.onCollapse}
-            className="h-7 w-7 rounded-lg text-muted-foreground hover:bg-sidebar-accent hover:text-sidebar-foreground"
-          >
-            <PanelLeftClose className="h-3.5 w-3.5" />
-          </Button>
-        </div>
+        <Button
+          variant="ghost"
+          size="icon"
+          aria-label={t("sidebar.collapse")}
+          onClick={props.onCollapse}
+          className="h-7 w-7 rounded-lg text-muted-foreground/85 hover:bg-sidebar-accent/75 hover:text-sidebar-foreground"
+        >
+          <PanelLeftClose className="h-3.5 w-3.5" />
+        </Button>
      </div>
-      <div className="px-2 pb-2">
+
+      <div className="space-y-1.5 px-2 pb-2">
+        <label className="relative block">
+          <span className="sr-only">{t("sidebar.searchAria")}</span>
+          <Search
+            className="pointer-events-none absolute left-3 top-1/2 h-3.5 w-3.5 -translate-y-1/2 text-muted-foreground/70"
+            aria-hidden
+          />
+          <input
+            value={query}
+            onChange={(event) => setQuery(event.target.value)}
+            placeholder={t("sidebar.searchPlaceholder")}
+            aria-label={t("sidebar.searchAria")}
+            className={cn(
+              "h-8 w-full rounded-full border border-transparent bg-sidebar-accent/45",
+              "pl-8 pr-3 text-[12.5px] text-sidebar-foreground outline-none",
+              "placeholder:text-muted-foreground/75",
+              "transition-colors hover:bg-sidebar-accent/65",
+              "focus:border-sidebar-border/80 focus:bg-sidebar-accent/70",
+              "focus:ring-1 focus:ring-sidebar-border/70",
+            )}
+          />
+        </label>
        <Button
          onClick={props.onNewChat}
-          className="h-9 w-full justify-start gap-2 rounded-full px-3 text-[13px] font-medium text-sidebar-foreground/90 hover:bg-sidebar-accent hover:text-sidebar-foreground"
+          className="h-8 w-full justify-start gap-2 rounded-full px-3 text-[12.5px] font-medium text-sidebar-foreground/92 hover:bg-sidebar-accent/75 hover:text-sidebar-foreground"
          variant="ghost"
        >
          <SquarePen className="h-3.5 w-3.5" />
          {t("sidebar.newChat")}
        </Button>
      </div>
-      <div className="flex items-center justify-between px-3 pb-1.5 pt-2.5 text-[11px] font-medium text-muted-foreground">
-        <span>{t("sidebar.recent")}</span>
-        <Button
-          variant="ghost"
-          size="icon"
-          className="h-6 w-6 rounded-md text-muted-foreground hover:bg-sidebar-accent hover:text-sidebar-foreground"
-          onClick={props.onRefresh}
-          aria-label={t("sidebar.refreshSessions")}
-        >
-          <RefreshCcw className="h-3.5 w-3.5" />
-        </Button>
-      </div>
      <div className="flex-1 overflow-hidden">
        <ChatList
-          sessions={props.sessions}
+          sessions={filteredSessions}
          activeKey={props.activeKey}
          loading={props.loading}
+          emptyLabel={
+            normalizedQuery ? t("sidebar.noSearchResults") : t("chat.noSessions")
+          }
          onSelect={props.onSelect}
          onRequestDelete={props.onRequestDelete}
        />
      </div>
      <Separator className="bg-sidebar-border/50" />
-      <div className="flex items-center justify-between gap-2 px-2.5 py-2 text-xs">
+      <div className="flex items-center px-2.5 py-2.5 text-xs">
        <ConnectionBadge />
-        <Button
-          onClick={props.onOpenSettings}
-          className="h-7 gap-1.5 rounded-md px-2 text-[11px] text-muted-foreground hover:bg-sidebar-accent hover:text-sidebar-foreground"
-          variant={props.activeView === "settings" ? "secondary" : "ghost"}
-        >
-          <Settings className="h-3.5 w-3.5" />
-          Settings
-        </Button>
      </div>
-    </aside>
+    </nav>
  );
 }
--- a/webui/src/components/thread/ThreadComposer.tsx
+++ b/webui/src/components/thread/ThreadComposer.tsx
@ -10,7 +10,7 @@ import {
  ArrowUp,
  ImageIcon,
  Loader2,
-  Paperclip,
+  Plus,
  X,
 } from "lucide-react";
 import { useTranslation } from "react-i18next";
@ -219,8 +219,8 @@ export function ThreadComposer({
        className={cn(
          "relative mx-auto flex w-full flex-col overflow-hidden transition-all duration-200",
          isHero
-            ? "max-w-[40rem] rounded-[24px] border border-border/75 bg-card shadow-[0_10px_30px_rgba(0,0,0,0.10)]"
-            : "max-w-[49.5rem] rounded-[16px] border border-border/70 bg-card",
+            ? "max-w-[58rem] rounded-[28px] border border-black/[0.035] bg-card shadow-[0_20px_55px_rgba(15,23,42,0.08)] dark:border-white/[0.06] dark:shadow-[0_24px_55px_rgba(0,0,0,0.34)]"
+            : "max-w-[49.5rem] rounded-[22px] border border-black/[0.035] bg-card shadow-[0_12px_30px_rgba(15,23,42,0.07)] dark:border-white/[0.06] dark:shadow-[0_16px_34px_rgba(0,0,0,0.28)]",
          "focus-within:ring-1 focus-within:ring-foreground/8",
          disabled && "opacity-60",
          isDragging && "ring-2 ring-primary/40 motion-reduce:ring-0 motion-reduce:border-primary",
@ -268,9 +268,9 @@ export function ThreadComposer({
          className={cn(
            "w-full resize-none bg-transparent",
            isHero
-              ? "min-h-[96px] px-4 pb-2 pt-4 text-[15px] leading-6"
+              ? "min-h-[78px] px-5 pb-2 pt-5 text-[16px] leading-6"
              : "min-h-[50px] px-4 pb-1.5 pt-3 text-sm",
-            "placeholder:text-muted-foreground",
+            "placeholder:text-muted-foreground/70",
            "focus:outline-none focus-visible:outline-none",
            "disabled:cursor-not-allowed",
          )}
@ -289,7 +289,7 @@ export function ThreadComposer({
        <div
          className={cn(
            "flex items-center justify-between gap-2",
-            isHero ? "px-3.5 pb-3.5" : "px-3 pb-2",
+            isHero ? "px-4 pb-4" : "px-3 pb-2",
          )}
        >
          <div className="flex min-w-0 items-center gap-2">
@ -310,10 +310,12 @@ export function ThreadComposer({
              onClick={() => fileInputRef.current?.click()}
              className={cn(
                "rounded-full text-muted-foreground hover:text-foreground",
-                isHero ? "h-8.5 w-8.5" : "h-7.5 w-7.5",
+                isHero
+                  ? "h-9 w-9 border border-border/55 bg-card shadow-[0_2px_8px_rgba(15,23,42,0.05)] hover:bg-card"
+                  : "h-7.5 w-7.5 border border-border/55 bg-card shadow-[0_2px_8px_rgba(15,23,42,0.05)] hover:bg-card",
              )}
            >
-              <Paperclip className={cn(isHero ? "h-4 w-4" : "h-3.5 w-3.5")} />
+              <Plus className={cn(isHero ? "h-5 w-5" : "h-4 w-4")} />
            </Button>
            {modelLabel ? (
              <span
@ -321,7 +323,9 @@ export function ThreadComposer({
                className={cn(
                  "inline-flex min-w-0 items-center gap-1.5 rounded-full border px-2.5 py-1",
                  "border-foreground/10 bg-foreground/[0.035] font-medium text-foreground/80",
-                  isHero ? "text-[11px]" : "text-[10.5px]",
+                  isHero
+                    ? "max-w-[13rem] text-[12px] shadow-[0_2px_8px_rgba(15,23,42,0.04)]"
+                    : "max-w-[10rem] text-[10.5px] shadow-[0_2px_8px_rgba(15,23,42,0.035)]",
                )}
              >
                <span
@ -331,19 +335,23 @@ export function ThreadComposer({
                <span className="truncate">{modelLabel}</span>
              </span>
            ) : null}
-            <span className="hidden select-none text-[10.5px] text-muted-foreground/60 sm:inline">
-              {t("thread.composer.sendHint")}
-            </span>
+            {!isHero ? (
+              <span className="hidden select-none text-[10.5px] text-muted-foreground/60 sm:inline">
+                {t("thread.composer.sendHint")}
+              </span>
+            ) : null}
          </div>
-          <span className="sm:hidden" aria-hidden />
+          <span className={cn(isHero ? "hidden" : "sm:hidden")} aria-hidden />
          <Button
            type="submit"
            size="icon"
            disabled={!canSend}
            aria-label={t("thread.composer.send")}
            className={cn(
-              "rounded-full border border-border/70 bg-secondary/85 text-secondary-foreground shadow-none transition-transform hover:bg-accent",
-              isHero ? "h-8.5 w-8.5" : "h-7.5 w-7.5",
+              isHero
+                ? "h-9 w-9 rounded-full border border-foreground bg-foreground text-background shadow-[0_4px_12px_rgba(15,23,42,0.20)] hover:bg-foreground/90 disabled:border-foreground/35 disabled:bg-foreground/35 disabled:text-background/80"
+                : "rounded-full border border-foreground bg-foreground text-background shadow-[0_3px_10px_rgba(15,23,42,0.18)] transition-transform hover:bg-foreground/90 disabled:border-foreground/35 disabled:bg-foreground/35 disabled:text-background/80",
+              isHero ? "" : "h-7.5 w-7.5",
              canSend && "hover:scale-[1.03] active:scale-95",
            )}
          >
--- a/webui/src/components/thread/ThreadHeader.tsx
+++ b/webui/src/components/thread/ThreadHeader.tsx
@ -1,4 +1,4 @@
-import { PanelLeftOpen } from "lucide-react";
+import { Menu, Moon, PanelLeftOpen, Settings, Sun } from "lucide-react";
 import { useTranslation } from "react-i18next";

 import { Button } from "@/components/ui/button";
@ -7,17 +7,66 @@ import { cn } from "@/lib/utils";
 interface ThreadHeaderProps {
  title: string;
  onToggleSidebar: () => void;
-  onGoHome: () => void;
+  theme: "light" | "dark";
+  onToggleTheme: () => void;
+  onOpenSettings: () => void;
  hideSidebarToggleOnDesktop?: boolean;
+  minimal?: boolean;
 }

 export function ThreadHeader({
  title,
  onToggleSidebar,
-  onGoHome,
+  theme,
+  onToggleTheme,
+  onOpenSettings,
  hideSidebarToggleOnDesktop = false,
+  minimal = false,
 }: ThreadHeaderProps) {
  const { t } = useTranslation();
+  if (minimal) {
+    return (
+      <div className="relative z-10 flex h-11 items-center justify-between gap-3 px-3 py-2">
+        <Button
+          variant="ghost"
+          size="icon"
+          aria-label={t("thread.header.toggleSidebar")}
+          onClick={onToggleSidebar}
+          className={cn(
+            "h-7 w-7 rounded-md text-muted-foreground hover:bg-accent/35 hover:text-foreground",
+            hideSidebarToggleOnDesktop && "lg:pointer-events-none lg:opacity-0",
+          )}
+        >
+          <Menu className="h-3.5 w-3.5" />
+        </Button>
+        <div className="flex items-center gap-0.5">
+          <Button
+            variant="ghost"
+            size="icon"
+            aria-label={t("thread.header.toggleTheme")}
+            onClick={onToggleTheme}
+            className="h-8 w-8 rounded-full text-muted-foreground/85 hover:bg-accent/40 hover:text-foreground"
+          >
+            {theme === "dark" ? (
+              <Sun className="h-4 w-4" />
+            ) : (
+              <Moon className="h-4 w-4" />
+            )}
+          </Button>
+          <Button
+            variant="ghost"
+            size="icon"
+            aria-label={t("thread.header.settings")}
+            onClick={onOpenSettings}
+            className="h-8 w-8 rounded-full text-muted-foreground/85 hover:bg-accent/40 hover:text-foreground"
+          >
+            <Settings className="h-4 w-4" />
+          </Button>
+        </div>
+      </div>
+    );
+  }
+
  return (
    <div className="relative z-10 flex items-center justify-between gap-3 px-3 py-2">
      <div className="relative flex min-w-0 items-center gap-2">
@ -33,19 +82,34 @@ export function ThreadHeader({
        >
          <PanelLeftOpen className="h-3.5 w-3.5" />
        </Button>
-        <button
-          type="button"
-          onClick={onGoHome}
-          className="flex min-w-0 items-center gap-2 rounded-md px-1.5 py-1 text-[12px] font-medium text-muted-foreground transition-colors hover:bg-accent/35 hover:text-foreground"
-        >
-          <img
-            src="/brand/nanobot_icon.png"
-            alt=""
-            className="h-4 w-4 rounded-[5px] opacity-85"
-            aria-hidden
-          />
+        <div className="flex min-w-0 items-center rounded-md px-1.5 py-1 text-[12px] font-medium text-muted-foreground">
          <span className="max-w-[min(60vw,32rem)] truncate">{title}</span>
-        </button>
+        </div>
+      </div>
+
+      <div className="flex items-center gap-0.5">
+        <Button
+          variant="ghost"
+          size="icon"
+          aria-label={t("thread.header.toggleTheme")}
+          onClick={onToggleTheme}
+          className="h-8 w-8 rounded-full text-muted-foreground/85 hover:bg-accent/40 hover:text-foreground"
+        >
+          {theme === "dark" ? (
+            <Sun className="h-4 w-4" />
+          ) : (
+            <Moon className="h-4 w-4" />
+          )}
+        </Button>
+        <Button
+          variant="ghost"
+          size="icon"
+          aria-label={t("thread.header.settings")}
+          onClick={onOpenSettings}
+          className="h-8 w-8 rounded-full text-muted-foreground/85 hover:bg-accent/40 hover:text-foreground"
+        >
+          <Settings className="h-4 w-4" />
+        </Button>
      </div>

      <div aria-hidden className="pointer-events-none absolute inset-x-0 top-full h-4" />
--- a/webui/src/components/thread/ThreadShell.tsx
+++ b/webui/src/components/thread/ThreadShell.tsx
@ -1,4 +1,13 @@
 import { useCallback, useEffect, useMemo, useRef, useState } from "react";
+import {
+  BarChart3,
+  BookOpen,
+  ChevronRight,
+  Code2,
+  LayoutGrid,
+  Lightbulb,
+  MoreHorizontal,
+} from "lucide-react";
 import { useTranslation } from "react-i18next";

 import { AskUserPrompt } from "@/components/thread/AskUserPrompt";
@ -15,8 +24,13 @@ interface ThreadShellProps {
  session: ChatSummary | null;
  title: string;
  onToggleSidebar: () => void;
-  onGoHome: () => void;
-  onNewChat: () => Promise<string | null>;
+  onGoHome?: () => void;
+  onNewChat?: () => void;
+  onCreateChat?: () => Promise<string | null>;
+  onTurnEnd?: () => void;
+  theme?: "light" | "dark";
+  onToggleTheme?: () => void;
+  onOpenSettings?: () => void;
  hideSidebarToggleOnDesktop?: boolean;
 }

@ -28,12 +42,24 @@ function toModelBadgeLabel(modelName: string | null): string | null {
  return leaf || trimmed;
 }

+const QUICK_ACTION_KEYS = [
+  { key: "plan", icon: LayoutGrid, tone: "text-[#f25b8f]" },
+  { key: "analyze", icon: BarChart3, tone: "text-[#4f9de8]" },
+  { key: "brainstorm", icon: Lightbulb, tone: "text-[#53c59d]" },
+  { key: "code", icon: Code2, tone: "text-[#eba45d]" },
+  { key: "summarize", icon: BookOpen, tone: "text-[#a877e7]" },
+  { key: "more", icon: MoreHorizontal, tone: "text-muted-foreground/65" },
+] as const;
+
 export function ThreadShell({
  session,
  title,
  onToggleSidebar,
-  onGoHome,
-  onNewChat,
+  onCreateChat,
+  onTurnEnd,
+  theme = "light",
+  onToggleTheme = () => {},
+  onOpenSettings = () => {},
  hideSidebarToggleOnDesktop = false,
 }: ThreadShellProps) {
  const { t } = useTranslation();
@ -57,7 +83,7 @@ export function ThreadShell({
    setMessages,
    streamError,
    dismissStreamError,
-  } = useNanobotStream(chatId, initial, hasPendingToolCalls);
+  } = useNanobotStream(chatId, initial, hasPendingToolCalls, onTurnEnd);
  const showHeroComposer = messages.length === 0 && !loading;
  const pendingAsk = useMemo(() => {
    for (let index = messages.length - 1; index >= 0; index -= 1) {
@ -125,13 +151,94 @@ export function ThreadShell({
      if (booting) return;
      setBooting(true);
      pendingFirstRef.current = content;
-      const newId = await onNewChat();
+      const newId = await onCreateChat?.();
      if (!newId) {
        pendingFirstRef.current = null;
        setBooting(false);
      }
    },
-    [booting, onNewChat],
+    [booting, onCreateChat],
+  );
+
+  const handleQuickAction = useCallback(
+    (prompt: string) => {
+      if (session) {
+        send(prompt);
+        return;
+      }
+      void handleWelcomeSend(prompt);
+    },
+    [handleWelcomeSend, send, session],
+  );
+
+  const quickActions = (
+    <div className="mx-auto grid w-full max-w-[58rem] grid-cols-2 gap-3 pt-4 sm:grid-cols-3 lg:grid-cols-6 lg:gap-4">
+      {QUICK_ACTION_KEYS.map(({ key, icon: Icon, tone }) => {
+        const title = t(`thread.empty.quickActions.${key}.title`);
+        const prompt = t(`thread.empty.quickActions.${key}.prompt`);
+        return (
+          <button
+            key={key}
+            type="button"
+            onClick={() => handleQuickAction(prompt)}
+            disabled={booting || isStreaming}
+            className="group flex min-h-[136px] flex-col justify-between rounded-[20px] border border-black/[0.035] bg-card px-5 py-5 text-left shadow-[0_14px_34px_rgba(15,23,42,0.07)] transition-all hover:-translate-y-0.5 hover:shadow-[0_18px_42px_rgba(15,23,42,0.10)] disabled:pointer-events-none disabled:opacity-60 dark:border-white/[0.06] dark:shadow-[0_16px_34px_rgba(0,0,0,0.28)]"
+          >
+            <Icon className={`h-[18px] w-[18px] ${tone}`} strokeWidth={2} />
+            <span className="max-w-[7.5rem] text-[15px] font-medium leading-[1.28] tracking-[-0.01em] text-foreground/82">
+              {title}
+            </span>
+            <ChevronRight className="h-4 w-4 self-end text-muted-foreground/45 transition-colors group-hover:text-muted-foreground" />
+          </button>
+        );
+      })}
+    </div>
+  );
+
+  const composer = (
+    <>
+      {streamError ? (
+        <StreamErrorNotice
+          error={streamError}
+          onDismiss={dismissStreamError}
+        />
+      ) : null}
+      {pendingAsk ? (
+        <AskUserPrompt
+          question={pendingAsk.question}
+          buttons={pendingAsk.buttons}
+          onAnswer={send}
+        />
+      ) : null}
+      {session ? (
+        <ThreadComposer
+          onSend={send}
+          disabled={!chatId}
+          isStreaming={isStreaming}
+          placeholder={
+            showHeroComposer
+              ? t("thread.composer.placeholderHero")
+              : t("thread.composer.placeholderThread")
+          }
+          modelLabel={toModelBadgeLabel(modelName)}
+          variant={showHeroComposer ? "hero" : "thread"}
+        />
+      ) : (
+        <ThreadComposer
+          onSend={handleWelcomeSend}
+          disabled={booting}
+          isStreaming={isStreaming}
+          placeholder={
+            booting
+              ? t("thread.composer.placeholderOpening")
+              : t("thread.composer.placeholderHero")
+          }
+          modelLabel={toModelBadgeLabel(modelName)}
+          variant="hero"
+        />
+      )}
+      {showHeroComposer ? quickActions : null}
+    </>
  );

  const emptyState = loading ? (
@ -139,20 +246,10 @@ export function ThreadShell({
      {t("thread.loadingConversation")}
    </div>
  ) : (
-    <div className="flex w-full max-w-[40rem] flex-col gap-2 text-left animate-in fade-in-0 slide-in-from-bottom-2 duration-500">
-      <div className="inline-flex items-center gap-2 text-[11px] font-medium text-muted-foreground">
-        <img
-          src="/brand/nanobot_icon.png"
-          alt=""
-          aria-hidden
-          draggable={false}
-          className="h-4 w-4 rounded-sm opacity-90"
-        />
-        <span className="text-foreground/82">nanobot</span>
-      </div>
-      <p className="max-w-[28rem] text-[13px] leading-6 text-muted-foreground">
-        {t("thread.empty.description")}
-      </p>
+    <div className="flex w-full flex-col items-center text-center animate-in fade-in-0 slide-in-from-bottom-2 duration-500">
+      <h1 className="text-balance text-[40px] font-normal leading-tight tracking-[-0.045em] text-foreground sm:text-[48px]">
+        {t("thread.empty.greeting")}
+      </h1>
    </div>
  );

@ -161,57 +258,17 @@ export function ThreadShell({
      <ThreadHeader
        title={title}
        onToggleSidebar={onToggleSidebar}
-        onGoHome={onGoHome}
+        theme={theme}
+        onToggleTheme={onToggleTheme}
+        onOpenSettings={onOpenSettings}
        hideSidebarToggleOnDesktop={hideSidebarToggleOnDesktop}
+        minimal={!session && !loading}
      />
      <ThreadViewport
        messages={messages}
        isStreaming={isStreaming}
        emptyState={emptyState}
-        composer={
-          <>
-            {streamError ? (
-              <StreamErrorNotice
-                error={streamError}
-                onDismiss={dismissStreamError}
-              />
-            ) : null}
-            {pendingAsk ? (
-              <AskUserPrompt
-                question={pendingAsk.question}
-                buttons={pendingAsk.buttons}
-                onAnswer={send}
-              />
-            ) : null}
-            {session ? (
-              <ThreadComposer
-                onSend={send}
-                disabled={!chatId}
-                isStreaming={isStreaming}
-                placeholder={
-                  showHeroComposer
-                    ? t("thread.composer.placeholderHero")
-                    : t("thread.composer.placeholderThread")
-                }
-                modelLabel={toModelBadgeLabel(modelName)}
-                variant={showHeroComposer ? "hero" : "thread"}
-              />
-            ) : (
-              <ThreadComposer
-                onSend={handleWelcomeSend}
-                disabled={booting}
-                isStreaming={isStreaming}
-                placeholder={
-                  booting
-                    ? t("thread.composer.placeholderOpening")
-                    : t("thread.composer.placeholderHero")
-                }
-                modelLabel={toModelBadgeLabel(modelName)}
-                variant="hero"
-              />
-            )}
-          </>
-        }
+        composer={composer}
      />
    </section>
  );
--- a/webui/src/components/thread/ThreadViewport.tsx
+++ b/webui/src/components/thread/ThreadViewport.tsx
@ -82,9 +82,9 @@ export function ThreadViewport({
            </div>
          </div>
        ) : (
-          <div className="mx-auto flex min-h-full w-full max-w-[64rem] flex-col px-4">
-            <div className="flex w-full flex-1 justify-center pb-16 pt-14 md:pt-[3.5rem]">
-              <div className="flex w-full max-w-[40rem] flex-col gap-5">
+          <div className="mx-auto flex min-h-full w-full max-w-[72rem] flex-col px-4">
+            <div className="flex w-full flex-1 items-center justify-center pb-[7vh] pt-8">
+              <div className="flex w-full max-w-[58rem] flex-col gap-6">
                {emptyState}
                <div className="w-full">{composer}</div>
              </div>
--- a/webui/src/globals.css
+++ b/webui/src/globals.css
@ -25,9 +25,9 @@
    --input: 0 0% 89.8%;
    --ring: 0 0% 3.9%;
    --radius: 0.4375rem;
-    --sidebar: 0 0% 98%;
+    --sidebar: 0 0% 98.5%;
    --sidebar-foreground: 0 0% 3.9%;
-    --sidebar-accent: 0 0% 96.1%;
+    --sidebar-accent: 0 0% 95.8%;
    --sidebar-accent-foreground: 0 0% 9%;
    --sidebar-border: 0 0% 89.8%;
  }
@ -52,9 +52,9 @@
    --border: 0 0% 18%;
    --input: 0 0% 18%;
    --ring: 0 0% 83.1%;
-    --sidebar: 0 0% 12%;
+    --sidebar: 0 0% 11.5%;
    --sidebar-foreground: 0 0% 98%;
-    --sidebar-accent: 0 0% 16%;
+    --sidebar-accent: 0 0% 15.5%;
    --sidebar-accent-foreground: 0 0% 98%;
    --sidebar-border: 0 0% 18%;
  }
--- a/webui/src/hooks/useNanobotStream.ts
+++ b/webui/src/hooks/useNanobotStream.ts
@ -38,6 +38,7 @@ export function useNanobotStream(
  chatId: string | null,
  initialMessages: UIMessage[] = [],
  hasPendingToolCalls = false,
+  onTurnEnd?: () => void,
 ): {
  messages: UIMessage[];
  isStreaming: boolean;
@ -159,6 +160,12 @@ export function useNanobotStream(
        setMessages((prev) =>
          prev.map((m) => (m.isStreaming ? { ...m, isStreaming: false } : m)),
        );
+        onTurnEnd?.();
+        return;
+      }
+
+      if (ev.event === "session_updated") {
+        onTurnEnd?.();
        return;
      }

@ -233,7 +240,7 @@ export function useNanobotStream(
        streamEndTimerRef.current = null;
      }
    };
-  }, [chatId, client]);
+  }, [chatId, client, onTurnEnd]);

  const send = useCallback(
    (content: string, images?: SendImage[]) => {
--- a/webui/src/hooks/useSessions.ts
+++ b/webui/src/hooks/useSessions.ts
@ -61,6 +61,7 @@ export function useSessions(): {
        chatId,
        createdAt: new Date().toISOString(),
        updatedAt: new Date().toISOString(),
+        title: "",
        preview: "",
      },
      ...prev.filter((s) => s.key !== key),
@ -221,7 +222,7 @@ export function sessionTitle(
  firstUserMessage?: string,
 ): string {
  return deriveTitle(
-    firstUserMessage || session.preview,
+    session.title || firstUserMessage || session.preview,
    i18n.t("chat.newChat"),
  );
 }
--- a/webui/src/i18n/locales/en/common.json
+++ b/webui/src/i18n/locales/en/common.json
@ -18,11 +18,19 @@
    }
  },
  "sidebar": {
+    "navigation": "Sidebar navigation",
+    "globalActions": "Global actions",
    "collapse": "Collapse sidebar",
    "toggleTheme": "Toggle theme",
+    "home": "Home",
    "newChat": "New chat",
+    "searchAria": "Search chats",
+    "searchPlaceholder": "Search chats",
+    "searchResults": "Results",
+    "noSearchResults": "No matching chats.",
    "recent": "Recent",
    "refreshSessions": "Refresh sessions",
+    "settings": "Settings",
    "language": {
      "label": "Language",
      "ariaLabel": "Change language"
@ -34,7 +42,12 @@
    "noSessions": "No sessions yet.",
    "actions": "Chat actions for {{title}}",
    "delete": "Delete",
-    "newChat": "New chat"
+    "newChat": "New chat",
+    "groups": {
+      "today": "Today",
+      "yesterday": "Yesterday",
+      "earlier": "Earlier"
+    }
  },
  "deleteConfirm": {
    "title": "Delete “{{title}}”?",
@ -53,20 +66,55 @@
  "thread": {
    "loadingConversation": "Loading conversation…",
    "empty": {
-      "description": "Ask questions, continue local work, or start a new thread."
+      "greeting": "What can I do for you?",
+      "quickActions": {
+        "plan": {
+          "title": "Create a project plan",
+          "prompt": "Create a concise project plan for what I should build next."
+        },
+        "analyze": {
+          "title": "Analyze this data",
+          "prompt": "Help me analyze this data and call out the most important patterns."
+        },
+        "brainstorm": {
+          "title": "Brainstorm ideas",
+          "prompt": "Brainstorm a few practical ideas and tradeoffs for this problem."
+        },
+        "code": {
+          "title": "Write code",
+          "prompt": "Help me write the code for this task, starting with the smallest useful change."
+        },
+        "summarize": {
+          "title": "Summarize this document",
+          "prompt": "Summarize this document and list the key takeaways."
+        },
+        "more": {
+          "title": "More",
+          "prompt": "Show me a few useful ways you can help in this workspace."
+        }
+      }
    },
    "header": {
-      "toggleSidebar": "Toggle sidebar"
+      "toggleSidebar": "Toggle sidebar",
+      "newChat": "Start a new chat",
+      "toggleTheme": "Toggle theme from header",
+      "settings": "Open settings"
    },
    "composer": {
      "placeholderThread": "Type your message…",
-      "placeholderHero": "What's on your mind?",
+      "placeholderHero": "Ask anything...",
      "placeholderOpening": "Opening a new chat…",
      "placeholderStreaming": "Model is responding…",
      "inputAria": "Message input",
      "sendHint": "Enter to send · Shift+Enter for newline",
      "send": "Send message",
      "attachImage": "Attach image",
+      "tools": {
+        "search": "Search",
+        "reason": "Reason",
+        "deepResearch": "Deep research",
+        "voice": "Voice input"
+      },
      "encoding": "Encoding…",
      "remove": "Remove attachment",
      "normalizedSizeHint": "{{orig}} → {{current}} (auto)",
@ -86,7 +134,9 @@
    "assistantTyping": "Assistant is typing",
    "toolSingle": "Using a tool",
    "toolMany": "Used {{count}} tools",
-    "imageAttachment": "Image attachment"
+    "imageAttachment": "Image attachment",
+    "copyReply": "Copy reply",
+    "copiedReply": "Copied reply"
  },
  "lightbox": {
    "title": "Image preview",
--- a/webui/src/i18n/locales/zh-CN/common.json
+++ b/webui/src/i18n/locales/zh-CN/common.json
@ -18,11 +18,19 @@
    }
  },
  "sidebar": {
+    "navigation": "侧边栏导航",
+    "globalActions": "全局操作",
    "collapse": "收起侧边栏",
    "toggleTheme": "切换主题",
+    "home": "首页",
    "newChat": "新建对话",
+    "searchAria": "搜索会话",
+    "searchPlaceholder": "搜索会话",
+    "searchResults": "搜索结果",
+    "noSearchResults": "没有匹配的会话。",
    "recent": "最近对话",
    "refreshSessions": "刷新会话",
+    "settings": "设置",
    "language": {
      "label": "语言",
      "ariaLabel": "切换语言"
@ -34,7 +42,12 @@
    "noSessions": "还没有会话。",
    "actions": "“{{title}}” 的会话操作",
    "delete": "删除",
-    "newChat": "新建对话"
+    "newChat": "新建对话",
+    "groups": {
+      "today": "今天",
+      "yesterday": "昨天",
+      "earlier": "更早"
+    }
  },
  "deleteConfirm": {
    "title": "删除“{{title}}”？",
@ -53,20 +66,55 @@
  "thread": {
    "loadingConversation": "正在加载对话…",
    "empty": {
-      "description": "可以提问、继续本地工作，或者开启一个新线程。"
+      "greeting": "我可以帮你做什么？",
+      "quickActions": {
+        "plan": {
+          "title": "创建项目计划",
+          "prompt": "帮我为接下来要做的事情写一份简洁的项目计划。"
+        },
+        "analyze": {
+          "title": "分析这些数据",
+          "prompt": "帮我分析这些数据，并指出最重要的模式。"
+        },
+        "brainstorm": {
+          "title": "头脑风暴想法",
+          "prompt": "围绕这个问题头脑风暴几个实用方案，并说明取舍。"
+        },
+        "code": {
+          "title": "编写代码",
+          "prompt": "帮我为这个任务写代码，先从最小可用改动开始。"
+        },
+        "summarize": {
+          "title": "总结这份文档",
+          "prompt": "帮我总结这份文档，并列出关键要点。"
+        },
+        "more": {
+          "title": "更多",
+          "prompt": "展示几个你在这个工作区里可以帮我的实用方式。"
+        }
+      }
    },
    "header": {
-      "toggleSidebar": "切换侧边栏"
+      "toggleSidebar": "切换侧边栏",
+      "newChat": "从顶部新建对话",
+      "toggleTheme": "从顶部切换主题",
+      "settings": "打开设置"
    },
    "composer": {
      "placeholderThread": "输入消息…",
-      "placeholderHero": "你在想什么？",
+      "placeholderHero": "问任何问题...",
      "placeholderOpening": "正在打开新对话…",
      "placeholderStreaming": "模型正在回复…",
      "inputAria": "消息输入框",
      "sendHint": "Enter 发送 · Shift+Enter 换行",
      "send": "发送消息",
      "attachImage": "添加图片",
+      "tools": {
+        "search": "搜索",
+        "reason": "推理",
+        "deepResearch": "深度研究",
+        "voice": "语音输入"
+      },
      "encoding": "处理中…",
      "remove": "移除附件",
      "normalizedSizeHint": "{{orig}} → {{current}}（已自动压缩）",
@ -86,7 +134,9 @@
    "assistantTyping": "助手正在输入",
    "toolSingle": "正在使用工具",
    "toolMany": "已使用 {{count}} 个工具",
-    "imageAttachment": "图片附件"
+    "imageAttachment": "图片附件",
+    "copyReply": "复制回复",
+    "copiedReply": "已复制回复"
  },
  "lightbox": {
    "title": "图片预览",
--- a/webui/src/lib/api.ts
+++ b/webui/src/lib/api.ts
@ -42,6 +42,7 @@ export async function listSessions(
    key: string;
    created_at: string | null;
    updated_at: string | null;
+    title?: string;
    preview?: string;
  };
  const body = await request<{ sessions: Row[] }>(
@ -53,6 +54,7 @@ export async function listSessions(
    ...splitKey(s.key),
    createdAt: s.created_at,
    updatedAt: s.updated_at,
+    title: s.title ?? "",
    preview: s.preview ?? "",
  }));
 }
--- a/webui/src/lib/nanobot-client.ts
+++ b/webui/src/lib/nanobot-client.ts
@ -185,8 +185,8 @@ export class NanobotClient {
    this.knownChats.add(chatId);
    const frame: Outbound =
      media && media.length > 0
-        ? { type: "message", chat_id: chatId, content, media }
-        : { type: "message", chat_id: chatId, content };
+        ? { type: "message", chat_id: chatId, content, media, webui: true }
+        : { type: "message", chat_id: chatId, content, webui: true };
    this.queueSend(frame);
  }

--- a/webui/src/lib/types.ts
+++ b/webui/src/lib/types.ts
@ -56,6 +56,7 @@ export interface ChatSummary {
  chatId: string;
  createdAt: string | null;
  updatedAt: string | null;
+  title?: string;
  preview: string;
 }

@ -125,6 +126,7 @@ export type InboundEvent =
      stream_id?: string;
    }
  | { event: "turn_end"; chat_id: string }
+  | { event: "session_updated"; chat_id: string }
  | { event: "error"; chat_id?: string; detail?: string };

 /** Base64-encoded image attached to an outbound ``message`` envelope.
@ -148,4 +150,7 @@ export type Outbound =
      chat_id: string;
      content: string;
      media?: OutboundMedia[];
+      /** Marks messages sent by the embedded WebUI, without changing the
+       * generic websocket protocol for other clients. */
+      webui?: true;
    };
--- a/webui/src/tests/api.test.ts
+++ b/webui/src/tests/api.test.ts
@ -1,6 +1,6 @@
 import { beforeEach, describe, expect, it, vi } from "vitest";

-import { deleteSession, fetchSessionMessages, updateSettings } from "@/lib/api";
+import { deleteSession, fetchSessionMessages, listSessions, updateSettings } from "@/lib/api";

 describe("webui API helpers", () => {
  beforeEach(() => {
@ -48,4 +48,28 @@ describe("webui API helpers", () => {
      }),
    );
  });
+
+  it("maps generated session titles from the sessions list", async () => {
+    vi.mocked(fetch).mockResolvedValueOnce({
+      ok: true,
+      json: async () => ({
+        sessions: [
+          {
+            key: "websocket:chat-1",
+            created_at: "2026-05-01T10:00:00",
+            updated_at: "2026-05-01T10:01:00",
+            title: "优化 WebUI 标题",
+          },
+        ],
+      }),
+    } as Response);
+
+    await expect(listSessions("tok")).resolves.toMatchObject([
+      {
+        key: "websocket:chat-1",
+        title: "优化 WebUI 标题",
+        preview: "",
+      },
+    ]);
+  });
 });
--- a/webui/src/tests/app-layout.test.tsx
+++ b/webui/src/tests/app-layout.test.tsx
@ -1,4 +1,4 @@
-import { fireEvent, render, screen, waitFor } from "@testing-library/react";
+import { fireEvent, render, screen, waitFor, within } from "@testing-library/react";
 import { beforeEach, describe, expect, it, vi } from "vitest";

 import type { ChatSummary } from "@/lib/types";
@ -7,6 +7,7 @@ const connectSpy = vi.fn();
 const refreshSpy = vi.fn();
 const createChatSpy = vi.fn().mockResolvedValue("chat-1");
 const deleteChatSpy = vi.fn();
+const toggleThemeSpy = vi.fn();
 let mockSessions: ChatSummary[] = [];

 vi.mock("@/hooks/useSessions", async (importOriginal) => {
@ -34,7 +35,7 @@ vi.mock("@/hooks/useSessions", async (importOriginal) => {
 vi.mock("@/hooks/useTheme", () => ({
  useTheme: () => ({
    theme: "light" as const,
-    toggle: vi.fn(),
+    toggle: toggleThemeSpy,
  }),
 }));

@ -74,6 +75,7 @@ describe("App layout", () => {
    refreshSpy.mockReset();
    createChatSpy.mockClear();
    deleteChatSpy.mockReset();
+    toggleThemeSpy.mockReset();
    vi.stubGlobal(
      "fetch",
      vi.fn().mockResolvedValue({
@ -121,8 +123,11 @@ describe("App layout", () => {
    render(<App />);

    await waitFor(() => expect(connectSpy).toHaveBeenCalled());
+    const sidebar = screen.getByRole("navigation", { name: "Sidebar navigation" });
    await waitFor(() =>
-      expect(screen.getByRole("button", { name: /^First chat$/ })).toBeInTheDocument(),
+      expect(
+        within(sidebar).getByRole("button", { name: /^First chat$/ }),
+      ).toBeInTheDocument(),
    );

    fireEvent.pointerDown(screen.getByLabelText("Chat actions for First chat"), {
@ -140,14 +145,24 @@ describe("App layout", () => {
    );
    await waitFor(() =>
      expect(
-        screen.getByRole("button", { name: /^Second chat$/ }),
+        within(sidebar).getByRole("button", { name: /^Second chat$/ }),
      ).toBeInTheDocument(),
    );
    expect(screen.queryByText('Delete “First chat”?')).not.toBeInTheDocument();
    expect(document.body.style.pointerEvents).not.toBe("none");
  }, 15_000);

-  it("opens the Cursor-style settings view from the sidebar", async () => {
+  it("opens the Cursor-style settings view from the header", async () => {
+    mockSessions = [
+      {
+        key: "websocket:chat-a",
+        channel: "websocket",
+        chatId: "chat-a",
+        createdAt: "2026-04-16T10:00:00Z",
+        updatedAt: "2026-04-16T10:00:00Z",
+        preview: "Existing chat",
+      },
+    ];
    vi.stubGlobal(
      "fetch",
      vi.fn(async (input: RequestInfo | URL) => {
@ -180,10 +195,95 @@ describe("App layout", () => {
    render(<App />);

    await waitFor(() => expect(connectSpy).toHaveBeenCalled());
-    fireEvent.click(screen.getByRole("button", { name: "Settings" }));
+    fireEvent.click(screen.getByRole("button", { name: "Open settings" }));

    expect(await screen.findByRole("heading", { name: "General" })).toBeInTheDocument();
    expect(screen.getByText("AI")).toBeInTheDocument();
    expect(screen.getByDisplayValue("openai/gpt-4o")).toBeInTheDocument();
  });
+
+  it("filters sidebar sessions through the lightweight search row", async () => {
+    mockSessions = [
+      {
+        key: "websocket:chat-alpha",
+        channel: "websocket",
+        chatId: "chat-alpha",
+        createdAt: new Date().toISOString(),
+        updatedAt: new Date().toISOString(),
+        preview: "Project planning notes",
+      },
+      {
+        key: "websocket:chat-beta",
+        channel: "websocket",
+        chatId: "chat-beta",
+        createdAt: "2026-04-15T10:00:00Z",
+        updatedAt: "2026-04-15T10:00:00Z",
+        preview: "Travel ideas",
+      },
+    ];
+
+    render(<App />);
+
+    await waitFor(() => expect(connectSpy).toHaveBeenCalled());
+    const sidebar = screen.getByRole("navigation", { name: "Sidebar navigation" });
+    expect(within(sidebar).getByText("Project planning notes")).toBeInTheDocument();
+    expect(within(sidebar).getByText("Travel ideas")).toBeInTheDocument();
+
+    fireEvent.change(screen.getByRole("textbox", { name: "Search chats" }), {
+      target: { value: "travel" },
+    });
+
+    expect(within(sidebar).queryByText("Project planning notes")).not.toBeInTheDocument();
+    expect(within(sidebar).getByText("Travel ideas")).toBeInTheDocument();
+  });
+
+  it("opens a blank start page without creating an empty chat", async () => {
+    mockSessions = [
+      {
+        key: "websocket:chat-a",
+        channel: "websocket",
+        chatId: "chat-a",
+        createdAt: "2026-04-16T10:00:00Z",
+        updatedAt: "2026-04-16T10:00:00Z",
+        preview: "Existing chat",
+      },
+    ];
+
+    const matchMedia = vi.fn().mockImplementation((query: string) => ({
+      matches: query.includes("1024px"),
+      media: query,
+      onchange: null,
+      addListener: vi.fn(),
+      removeListener: vi.fn(),
+      addEventListener: vi.fn(),
+      removeEventListener: vi.fn(),
+      dispatchEvent: vi.fn(),
+    }));
+    vi.stubGlobal("matchMedia", matchMedia);
+
+    const { container } = render(<App />);
+
+    await waitFor(() => expect(connectSpy).toHaveBeenCalled());
+
+    fireEvent.click(screen.getByRole("button", { name: "Toggle theme from header" }));
+    expect(toggleThemeSpy).toHaveBeenCalledTimes(1);
+
+    fireEvent.click(screen.getByRole("button", { name: "Collapse sidebar" }));
+    const desktopAside = container.querySelector("aside.lg\\:block") as HTMLElement;
+    await waitFor(() => expect(desktopAside.style.width).toBe("0px"));
+
+    expect(screen.queryByRole("button", { name: "Start a new chat" })).not.toBeInTheDocument();
+    fireEvent.click(screen.getByRole("button", { name: "Toggle sidebar" }));
+    await waitFor(() => expect(desktopAside.style.width).toBe("272px"));
+
+    const sidebar = screen.getByRole("navigation", { name: "Sidebar navigation" });
+    fireEvent.click(within(sidebar).getByRole("button", { name: "New chat" }));
+    expect(createChatSpy).not.toHaveBeenCalled();
+    expect(screen.getByText("What can I do for you?")).toBeInTheDocument();
+    expect(screen.queryByRole("button", { name: "Start a new chat" })).not.toBeInTheDocument();
+    expect(screen.getByRole("button", { name: "Toggle theme from header" })).toBeInTheDocument();
+    expect(screen.getByRole("button", { name: "Open settings" })).toBeInTheDocument();
+
+    expect(within(sidebar).getByText("Existing chat")).toBeInTheDocument();
+  });
 });
--- a/webui/src/tests/message-bubble.test.tsx
+++ b/webui/src/tests/message-bubble.test.tsx
@ -1,5 +1,5 @@
-import { fireEvent, render, screen } from "@testing-library/react";
-import { describe, expect, it } from "vitest";
+import { fireEvent, render, screen, waitFor } from "@testing-library/react";
+import { describe, expect, it, vi } from "vitest";

 import { MessageBubble } from "@/components/MessageBubble";
 import type { UIMessage } from "@/lib/types";
@ -19,6 +19,44 @@ describe("MessageBubble", () => {

    expect(row).toHaveClass("ml-auto", "flex");
    expect(pill).toHaveClass("ml-auto", "w-fit", "rounded-[18px]");
+    expect(screen.queryByRole("button", { name: "Copy reply" })).not.toBeInTheDocument();
+  });
+
+  it("copies completed assistant replies from the action row", async () => {
+    const writeText = vi.fn().mockResolvedValue(undefined);
+    Object.defineProperty(navigator, "clipboard", {
+      configurable: true,
+      value: { writeText },
+    });
+    const message: UIMessage = {
+      id: "a-copy",
+      role: "assistant",
+      content: "I can help with the next step.",
+      createdAt: Date.now(),
+    };
+
+    render(<MessageBubble message={message} />);
+
+    fireEvent.click(screen.getByRole("button", { name: "Copy reply" }));
+
+    expect(writeText).toHaveBeenCalledWith("I can help with the next step.");
+    await waitFor(() =>
+      expect(screen.getByRole("button", { name: "Copied reply" })).toBeInTheDocument(),
+    );
+  });
+
+  it("does not show copy actions for streaming placeholders", () => {
+    const message: UIMessage = {
+      id: "a-streaming",
+      role: "assistant",
+      content: "",
+      isStreaming: true,
+      createdAt: Date.now(),
+    };
+
+    render(<MessageBubble message={message} />);
+
+    expect(screen.queryByRole("button", { name: "Copy reply" })).not.toBeInTheDocument();
  });

  it("renders trace messages as collapsible tool groups", () => {
--- a/webui/src/tests/nanobot-client.test.ts
+++ b/webui/src/tests/nanobot-client.test.ts
@ -116,7 +116,7 @@ describe("NanobotClient", () => {
    // Attach is sent first because sendMessage adds to knownChats, which
    // handleOpen re-attaches; then the queued message follows.
    expect(lastSocket().sent).toContain(
-      JSON.stringify({ type: "message", chat_id: "chat-x", content: "hello" }),
+      JSON.stringify({ type: "message", chat_id: "chat-x", content: "hello", webui: true }),
    );
  });

@ -196,6 +196,7 @@ describe("NanobotClient", () => {
      chat_id: "chat-x",
      content: "look",
      media: [{ data_url: "data:image/png;base64,AAAA", name: "shot.png" }],
+      webui: true,
    });
  });

@ -214,6 +215,7 @@ describe("NanobotClient", () => {
      type: "message",
      chat_id: "chat-x",
      content: "hello",
+      webui: true,
    });
  });

--- a/webui/src/tests/thread-composer.test.tsx
+++ b/webui/src/tests/thread-composer.test.tsx
@ -9,15 +9,38 @@ describe("ThreadComposer", () => {
      <ThreadComposer
        onSend={vi.fn()}
        modelLabel="claude-opus-4-5"
-        placeholder="What's on your mind?"
+        placeholder="Ask anything..."
        variant="hero"
      />,
    );

    expect(screen.getByText("claude-opus-4-5")).toBeInTheDocument();
-    const input = screen.getByPlaceholderText("What's on your mind?");
+    expect(screen.queryByRole("button", { name: "Search" })).not.toBeInTheDocument();
+    expect(screen.queryByRole("button", { name: "Reason" })).not.toBeInTheDocument();
+    expect(screen.queryByRole("button", { name: "Deep research" })).not.toBeInTheDocument();
+    expect(screen.queryByRole("button", { name: "Voice input" })).not.toBeInTheDocument();
+    const input = screen.getByPlaceholderText("Ask anything...");
    expect(input).toBeInTheDocument();
-    expect(input.className).toContain("min-h-[96px]");
-    expect(input.parentElement?.className).toContain("max-w-[40rem]");
+    expect(input.className).toContain("min-h-[78px]");
+    expect(input.parentElement?.className).toContain("max-w-[58rem]");
+  });
+
+  it("keeps the thread composer compact while matching the hero style", () => {
+    render(
+      <ThreadComposer
+        onSend={vi.fn()}
+        modelLabel="gpt-4o"
+        placeholder="Type your message..."
+      />,
+    );
+
+    expect(screen.getByText("gpt-4o")).toBeInTheDocument();
+    const input = screen.getByPlaceholderText("Type your message...");
+    expect(input.className).toContain("min-h-[50px]");
+    expect(input.parentElement?.className).toContain("max-w-[49.5rem]");
+    expect(input.parentElement?.className).toContain("rounded-[22px]");
+    expect(input.parentElement?.className).toContain("shadow-[0_12px_30px_rgba(15,23,42,0.07)]");
+    expect(screen.getByRole("button", { name: "Attach image" }).className).toContain("bg-card");
+    expect(screen.getByRole("button", { name: "Send message" }).className).toContain("bg-foreground");
  });
 });
--- a/webui/src/tests/thread-shell.test.tsx
+++ b/webui/src/tests/thread-shell.test.tsx
@ -86,6 +86,26 @@ describe("ThreadShell", () => {
    );
  });

+  it("does not navigate away when clicking the chat title", async () => {
+    const client = makeClient();
+    const onGoHome = vi.fn();
+    render(wrap(
+      client,
+      <ThreadShell
+        session={session("chat-title")}
+        title="Important conversation"
+        onToggleSidebar={() => {}}
+        onGoHome={onGoHome}
+        onNewChat={() => {}}
+      />,
+    ));
+
+    await waitFor(() => expect(screen.getByText("Important conversation")).toBeInTheDocument());
+    fireEvent.click(screen.getByText("Important conversation"));
+
+    expect(onGoHome).not.toHaveBeenCalled();
+  });
+
  it("restores in-memory messages when switching away and back to a session", async () => {
    const client = makeClient();
    const onNewChat = vi.fn().mockResolvedValue("chat-a");
@ -199,7 +219,67 @@ describe("ThreadShell", () => {
    await waitFor(() => {
      expect(screen.queryByText("delete me cleanly")).not.toBeInTheDocument();
    });
-    expect(screen.getByPlaceholderText("What's on your mind?")).toBeInTheDocument();
+    expect(screen.getByPlaceholderText("Ask anything...")).toBeInTheDocument();
+  });
+
+  it("creates a chat only when the blank landing sends a first message", async () => {
+    const client = makeClient();
+    const onNewChat = vi.fn();
+    const onCreateChat = vi.fn().mockResolvedValue("chat-new");
+
+    render(
+      wrap(
+        client,
+        <ThreadShell
+          session={null}
+          title="nanobot"
+          onToggleSidebar={() => {}}
+          onGoHome={() => {}}
+          onNewChat={onNewChat}
+          onCreateChat={onCreateChat}
+        />,
+      ),
+    );
+
+    fireEvent.change(screen.getByLabelText("Message input"), {
+      target: { value: "start for real" },
+    });
+    fireEvent.click(screen.getByRole("button", { name: "Send message" }));
+
+    await waitFor(() => expect(onCreateChat).toHaveBeenCalledTimes(1));
+    expect(onNewChat).not.toHaveBeenCalled();
+  });
+
+  it("sends quick action prompts from the empty thread landing", async () => {
+    const client = makeClient();
+    const onNewChat = vi.fn().mockResolvedValue("chat-a");
+
+    render(
+      wrap(
+        client,
+        <ThreadShell
+          session={session("chat-a")}
+          title="Chat chat-a"
+          onToggleSidebar={() => {}}
+          onGoHome={() => {}}
+          onNewChat={onNewChat}
+        />,
+      ),
+    );
+
+    await waitFor(() => {
+      expect(screen.getByRole("button", { name: "Write code" })).toBeInTheDocument();
+    });
+
+    fireEvent.click(screen.getByRole("button", { name: "Write code" }));
+
+    await waitFor(() =>
+      expect(client.sendMessage).toHaveBeenCalledWith(
+        "chat-a",
+        "Help me write the code for this task, starting with the smallest useful change.",
+        undefined,
+      ),
+    );
  });

  it("does not leak the previous thread when opening a brand-new chat", async () => {
@ -260,10 +340,10 @@ describe("ThreadShell", () => {

    expect(screen.queryByText("old answer")).not.toBeInTheDocument();
    await waitFor(() =>
-      expect(screen.getByPlaceholderText("What's on your mind?")).toBeInTheDocument(),
+      expect(screen.getByPlaceholderText("Ask anything...")).toBeInTheDocument(),
    );
-    const input = screen.getByPlaceholderText("What's on your mind?");
-    expect(input.className).toContain("min-h-[96px]");
+    const input = screen.getByPlaceholderText("Ask anything...");
+    expect(input.className).toContain("min-h-[78px]");
    expect(screen.queryByText("old answer")).not.toBeInTheDocument();
  });

--- a/webui/src/tests/useNanobotStream.test.tsx
+++ b/webui/src/tests/useNanobotStream.test.tsx
@ -159,7 +159,8 @@ describe("useNanobotStream", () => {

  it("keeps streaming alive across stream_end and completes on turn_end", () => {
    const fake = fakeClient();
-    const { result } = renderHook(() => useNanobotStream("chat-s", EMPTY_MESSAGES), {
+    const onTurnEnd = vi.fn();
+    const { result } = renderHook(() => useNanobotStream("chat-s", EMPTY_MESSAGES, false, onTurnEnd), {
      wrapper: wrap(fake.client),
    });

@ -211,5 +212,23 @@ describe("useNanobotStream", () => {

    expect(result.current.isStreaming).toBe(false);
    expect(result.current.messages.every((message) => !message.isStreaming)).toBe(true);
+    expect(onTurnEnd).toHaveBeenCalledTimes(1);
+  });
+
+  it("refreshes session metadata when the server reports a session update", () => {
+    const fake = fakeClient();
+    const onTurnEnd = vi.fn();
+    renderHook(() => useNanobotStream("chat-title", EMPTY_MESSAGES, false, onTurnEnd), {
+      wrapper: wrap(fake.client),
+    });
+
+    act(() => {
+      fake.emit("chat-title", {
+        event: "session_updated",
+        chat_id: "chat-title",
+      });
+    });
+
+    expect(onTurnEnd).toHaveBeenCalledTimes(1);
  });
 });