debug: 修复新会话是query参数的问题

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

@@ -47,7 +47,7 @@ export default function AgentChatPage() {
       history.replaceState(
         null,
         "",
-        `/workspace/agents/${agent_name}/chats/${threadId}`,
+        `/workspace/agents/${agent_name}/chats/new?isnew=false&thread_id=${threadId}`,
       );
     },
     onFinish: (state) => {

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

@@ -32,7 +32,7 @@ import { useNotification } from "@/core/notification/hooks";
 import { useLocalSettings } from "@/core/settings";
 // [移植自 main 分支 ef9a071] 导入 skill 初始化 API
 import { bootstrapRemoteSkill } from "@/core/skills";
-import { useThreadStream } from "@/core/threads/hooks";
+import { useThreadStream, useTruncateThread } from "@/core/threads/hooks";
 import { textOfMessage } from "@/core/threads/utils";
 import { env } from "@/env";
 import { cn } from "@/lib/utils";
@@ -71,6 +71,21 @@ export default function ChatPage() {
 
   const { showNotification } = useNotification();
 
+  // 截断会话 hook
+  const truncateThread = useTruncateThread();
+  // 跟踪已截断的 threadId，避免重复截断
+  const truncatedThreadIdRef = useRef<string | null>(null);
+
+  // 当 isnew=false 且有 thread_id 时，截断会话历史
+  useEffect(() => {
+    // 只在非新会话且需要复用 thread_id 时截断
+    if (!createNewSession && threadId && truncatedThreadIdRef.current !== threadId) {
+      console.log("[ChatPage] Truncating thread:", threadId);
+      truncatedThreadIdRef.current = threadId;
+      truncateThread.mutate({ threadId });
+    }
+  }, [createNewSession, threadId, truncateThread]);
+
   // [移植自 main 分支 ef9a071] skill 初始化状态
   const [isSkillBootstrapping, setIsSkillBootstrapping] = useState(false);
   const skillBootstrappedKeyRef = useRef<string | null>(null);
@@ -180,7 +195,9 @@ export default function ChatPage() {
   }, [threadId, skillBootstrap, showNotification]);
 
   const [thread, sendMessage] = useThreadStream({
-    threadId: isNewThread ? undefined : threadId,
+    // [修复] 使用 createNewSession 而不是 isNewThread 来决定是否创建新会话
+    // isnew=false 时应该复用现有 threadId，不应该是 undefined
+    threadId: createNewSession ? undefined : threadId,
     context: settings.context,
     isMock,
     // [移植自 main 分支 4119fdc] 传递 uploadTarget
@@ -188,7 +205,11 @@ export default function ChatPage() {
     onStart: () => {
       setIsNewThread(false);
       // ! Important: Never use next.js router for navigation in this case, otherwise it will cause the thread to re-mount and lose all states. Use native history API instead.
-      history.replaceState(null, "", `/workspace/chats/${threadId}`);
+      history.replaceState(
+        null,
+        "",
+        `/workspace/chats/new?isnew=false&thread_id=${threadId}`,
+      );
     },
     onFinish: (state) => {
       if (document.hidden || !document.hasFocus()) {

frontend/src/app/workspace/layout.tsx

@@ -37,7 +37,7 @@ export default function WorkspaceLayout({
         onOpenChange={handleOpenChange}
       >
         {/* TODO: ！！！！必须注释！！！！！ */}
-        {/* <WorkspaceSidebar className="" /> */}
+        <WorkspaceSidebar className="" />
         <SidebarInset className="min-w-0">{children}</SidebarInset>
       </SidebarProvider>
       <Toaster />

frontend/src/app/workspace/page.tsx

@@ -13,7 +13,9 @@ export default function WorkspacePage() {
       })
       .find((thread) => thread.isDirectory() && !thread.name.startsWith("."));
     if (firstThread) {
-      return redirect(`/workspace/chats/${firstThread.name}`);
+      return redirect(
+        `/workspace/chats/new?isnew=false&thread_id=${firstThread.name}`,
+      );
     }
   }
   return redirect("/workspace/chats/new");

frontend/src/components/workspace/chats/use-thread-chat.ts

@@ -77,12 +77,17 @@ export function useThreadChat(): ThreadChatResult {
     return result;
   }, [threadIdFromPath, searchParams]);
 
-  // [移植自 main 分支 e2fdfa7] UI模式仅依赖路由：/workspace/chats/new 总是"新页面"模式
+  // [移植自 main 分支 e2fdfa7] UI模式：如果有 thread_id 参数则认为是已有会话
   const isNewThread = useMemo(() => {
-    const result = threadIdFromPath === "new";
-    console.log("[useThreadChat] isNewThread:", result);
-    return result;
-  }, [threadIdFromPath]);
+    if (threadIdFromPath !== "new") {
+      return false;
+    }
+    // 有 thread_id 参数说明是复用现有会话
+    if (queryThreadId) {
+      return false;
+    }
+    return true;
+  }, [threadIdFromPath, queryThreadId]);
 
   // [移植自 main 分支 4119fdc] 获取上传目标
   const uploadTarget = useMemo(() => {
@@ -212,12 +217,15 @@ export function useThreadChat(): ThreadChatResult {
     if (threadIdFromPath === "new") {
       // [移植自 main 分支 4119fdc] 优先使用 URL 中的 thread_id
       threadIdRef.current = queryThreadId || uuid();
-      isNewThreadRef.current = true;
+      // 如果有 queryThreadId，说明是复用现有会话，不是新会话
+      isNewThreadRef.current = !queryThreadId;
       console.log(
         "[useThreadChat] initial threadId (new route):",
         threadIdRef.current,
         "queryThreadId:",
         queryThreadId,
+        "isNewThread:",
+        isNewThreadRef.current,
       );
     } else {
       threadIdRef.current = threadIdFromPath;
@@ -232,6 +240,17 @@ export function useThreadChat(): ThreadChatResult {
   const [threadId, setThreadId] = useState(threadIdRef.current);
   const [isNewThreadState, setIsNewThread] = useState(isNewThreadRef.current);
 
+  // 监听 queryThreadId 变化，更新 threadId
+  useEffect(() => {
+    // 当 URL 中的 thread_id 参数变化时，更新 threadId
+    if (queryThreadId && queryThreadId !== threadId) {
+      console.log("[useThreadChat] queryThreadId changed, updating threadId:", queryThreadId);
+      threadIdRef.current = queryThreadId;
+      setThreadId(queryThreadId);
+      setIsNewThread(false);
+    }
+  }, [queryThreadId, threadId]);
+
   useEffect(() => {
     console.log("[useThreadChat] useEffect: pathname changed to:", pathname);
     if (pathname.endsWith("/new")) {

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

@@ -168,6 +168,12 @@ export function InputBox({
   const [isFocused, setIsFocused] = useState(false);
   const containerRef = useRef<HTMLDivElement | null>(null);
 
+  // isNewThread 变化时重置 isFocused 状态
+  useEffect(() => {
+    setIsFocused(false);
+    onFocusChange?.(false);
+  }, [isNewThread, onFocusChange]);
+
   // isNewThread 时禁用收缩，始终保持展开
   const effectiveIsFocused = isNewThread || isFocused;
 
@@ -1035,6 +1041,19 @@ function IframeSkillDialogButton({
 }) {
   const { t } = useI18n();
 
+  // TODO: 测试按钮，模拟宿主页发送 postMessage，测试完成后删除
+  const handleTestPostMessage = () => {
+    const testMessage = {
+      type: "selectedSkill",
+      id: 5,
+      title: "文档处理",
+    };
+    console.log("[Test] Simulating postMessage from parent:", testMessage);
+    window.dispatchEvent(
+      new MessageEvent("message", { data: testMessage })
+    );
+  };
+
   return (
     <div className="flex items-center gap-2">
       <Tooltip content={t.inputBox.selectSkill}>
@@ -1055,6 +1074,14 @@ function IframeSkillDialogButton({
           </svg>
         </PromptInputButton>
       </Tooltip>
+      {/* TODO: 测试按钮，测试完成后删除
+      <button
+        type="button"
+        onClick={handleTestPostMessage}
+        className="rounded bg-blue-500 px-2 py-1 text-xs text-white hover:bg-blue-600"
+      >
+        测试postMessage
+      </button> */}
       {selectedSkill && (
         <Badge
           variant="secondary"

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

@@ -59,15 +59,15 @@ export function RecentChatList() {
       deleteThread({ threadId });
       if (threadId === threadIdFromPath) {
         const threadIndex = threads.findIndex((t) => t.thread_id === threadId);
-        let nextThreadId = "new";
+        let nextPath = "/workspace/chats/new";
         if (threadIndex > -1) {
           if (threads[threadIndex + 1]) {
-            nextThreadId = threads[threadIndex + 1]!.thread_id;
+            nextPath = `/workspace/chats/new?isnew=false&thread_id=${threads[threadIndex + 1]!.thread_id}`;
           } else if (threads[threadIndex - 1]) {
-            nextThreadId = threads[threadIndex - 1]!.thread_id;
+            nextPath = `/workspace/chats/new?isnew=false&thread_id=${threads[threadIndex - 1]!.thread_id}`;
           }
         }
-        void router.push(`/workspace/chats/${nextThreadId}`);
+        void router.push(nextPath);
       }
     },
     [deleteThread, router, threadIdFromPath, threads],
@@ -100,7 +100,7 @@ export function RecentChatList() {
         window.location.hostname === "127.0.0.1";
       // On localhost: use Vercel URL; On production: use current origin
       const baseUrl = isLocalhost ? VERCEL_URL : window.location.origin;
-      const shareUrl = `${baseUrl}/workspace/chats/${threadId}`;
+      const shareUrl = `${baseUrl}/workspace/chats/new?isnew=false&thread_id=${threadId}`;
       try {
         await navigator.clipboard.writeText(shareUrl);
         toast.success(t.clipboard.linkCopied);

frontend/src/core/threads/hooks.ts

@@ -71,8 +71,8 @@ export function useThreadStream({
 
   useEffect(() => {
     const normalizedThreadId = threadId ?? null;
-    if (!normalizedThreadId) {
-      // Just reset for new thread creation when threadId becomes null/undefined
+    // 当 threadId 变化时，更新 onStreamThreadId 以重新获取数据
+    if (normalizedThreadId !== threadIdRef.current) {
       startedRef.current = false;
       setOnStreamThreadId(normalizedThreadId);
     }
@@ -533,3 +533,16 @@ export function useRenameThread() {
     },
   });
 }
+
+// 截断会话历史（清空消息）
+export function useTruncateThread() {
+  const apiClient = getAPIClient();
+  return useMutation({
+    mutationFn: async ({ threadId }: { threadId: string }) => {
+      // 通过更新 state，设置 messages 为空数组来截断会话
+      await apiClient.threads.updateState(threadId, {
+        values: { messages: [] },
+      });
+    },
+  });
+}

frontend/src/core/threads/utils.ts

@@ -3,7 +3,7 @@ import type { Message } from "@langchain/langgraph-sdk";
 import type { AgentThread } from "./types";
 
 export function pathOfThread(threadId: string) {
-  return `/workspace/chats/${threadId}`;
+  return `/workspace/chats/new?isnew=false&thread_id=${threadId}`;
 }
 
 export function textOfMessage(message: Message) {

frontend/src/hooks/use-iframe-skill.ts

@@ -21,6 +21,22 @@ interface UseIframeSkillReturn {
   clearSkill: () => void;
 }
 
+// 来自宿主页的 postMessage 类型
+interface SelectedSkillMessage {
+  type: "selectedSkill";
+  id: number;
+  title: string;
+}
+
+function isSelectedSkillMessage(data: unknown): data is SelectedSkillMessage {
+  return (
+    typeof data === "object" &&
+    data !== null &&
+    (data as SelectedSkillMessage).type === "selectedSkill" &&
+    typeof (data as SelectedSkillMessage).id === "number"
+  );
+}
+
 export function useIframeSkill(): UseIframeSkillReturn {
   const searchParams = useSearchParams();
   const skillIdFromQuery = searchParams.get("skill_id");
@@ -43,6 +59,24 @@ export function useIframeSkill(): UseIframeSkillReturn {
     }
   }, [skillIdFromQuery, titleFromQuery]);
 
+  // 监听来自宿主页的 postMessage
+  useEffect(() => {
+    const handleMessage = (event: MessageEvent) => {
+      if (!isSelectedSkillMessage(event.data)) {
+        return;
+      }
+      const { id, title } = event.data;
+      console.log("[useIframeSkill] Received selectedSkill from parent:", {
+        id,
+        title,
+      });
+      setSelectedSkill({ skill_id: String(id), title });
+    };
+
+    window.addEventListener("message", handleMessage);
+    return () => window.removeEventListener("message", handleMessage);
+  }, []);
+
   // 发送选择预定义 skill
   const sendSelectSkill = useCallback((skill_id: string) => {
     const message = { type: MESSAGE_TYPES.SELECT_SKILL, skill_id };