diff --git a/frontend/src/app/workspace/chats/[thread_id]/page.tsx b/frontend/src/app/workspace/chats/[thread_id]/page.tsx
index b4508e06..91aa89cf 100644
--- a/frontend/src/app/workspace/chats/[thread_id]/page.tsx
+++ b/frontend/src/app/workspace/chats/[thread_id]/page.tsx
@@ -61,7 +61,6 @@ export default function ChatPage() {
     setIsNewThread,
     isMock,
     showWelcomeStyle,
-    invalidNewRoute,
   } = useThreadChat();
   
   // 新逻辑：历史渲染和新会话仅由路由 /chats/new 控制，不再读取 isnew/xclaw_used 参数。
@@ -119,7 +118,6 @@ export default function ChatPage() {
   }, [thread.values?.title]);
 
   const [hasSubmitted, setHasSubmitted] = useState(false);
-  const showInputBox = !invalidNewRoute && !(showWelcomeStyle && thread.isThreadLoading);
   const [historyCutoff, setHistoryCutoff] = useState<number | null>(null);
 
   useEffect(() => {
@@ -214,12 +212,10 @@ export default function ChatPage() {
     setArtifactsOpen,
     setIsNewThread,
   ]);
-  // shouldRenderHistory || historyCutoff === null
-  // console.log('shouldRenderHistory', shouldRenderHistory, 'historyCutoff', historyCutoff);
   
 
   return (
-    <ThreadContext.Provider value={{ thread }}>
+    <ThreadContext.Provider value={{ threadId,thread }}>
       <div
         className={cn(
           "m-auto flex h-screen min-h-svh overflow-hidden rounded-t-[20px] transition-[width] duration-300 ease-in-out",
@@ -313,43 +309,22 @@ export default function ChatPage() {
                 )}
               >
                 <div className="flex size-full justify-center">
-                  {invalidNewRoute ? (
-                    <div className="flex size-full items-center justify-center px-6">
-                      <div
-                        className="max-w-md rounded-2xl border border-[#E5DDF2] bg-white px-6 py-5 text-center shadow-sm"
-                        data-testid="missing-thread-id-state"
-                        role="alert"
-                      >
-                        <h2 className="text-base font-semibold text-[#150033]">
-                          缺少 thread_id 参数
-                        </h2>
-                        <p className="mt-2 text-sm text-[#666666]">
-                          访问
-                          <span className="mx-1 font-mono">/workspace/chats/new</span>
-                          时必须显式传入
-                          <span className="mx-1 font-mono">?thread_id=...</span>
-                          ，当前页面不会继续使用本地缓存兜底。
-                        </p>
-                      </div>
-                    </div>
-                  ) : (
-                    <MessageList
-                      className={cn(
-                        "size-full",
-                        (!showWelcomeStyle || hasSubmitted) && "pt-[58px]",
-                      )}
-                      threadId={threadId}
-                      thread={thread}
-                      messagesOverride={
-                        shouldRenderHistory || historyCutoff === null
-                          ? undefined
-                          : thread.messages.slice(historyCutoff)
-                      }
-                      paddingBottom={todoListCollapsed ? 160 : 280}
-                      showScrollToBottomButton={!showWelcomeStyle}
-                      scrollButtonClassName="bottom-[112px]"
-                    />
-                  )}
+                  <MessageList
+                    className={cn(
+                      "size-full",
+                      (!showWelcomeStyle || hasSubmitted) && "pt-[58px]",
+                    )}
+                    threadId={threadId}
+                    thread={thread}
+                    messagesOverride={
+                      shouldRenderHistory || historyCutoff === null
+                        ? undefined
+                        : thread.messages.slice(historyCutoff)
+                    }
+                    paddingBottom={todoListCollapsed ? 160 : 280}
+                    showScrollToBottomButton={!showWelcomeStyle}
+                    scrollButtonClassName="bottom-[112px]"
+                  />
                 </div>
               </main>
             </div>
@@ -433,7 +408,7 @@ export default function ChatPage() {
               showWelcomeStyle && !hasSubmitted && "-translate-y-[calc(50vh-96px)]",
             )}
           >
-            {showInputBox ? (
+            {!(showWelcomeStyle && thread.isThreadLoading) ? (
               <InputBox
                 className={cn("w-full rounded-[20px] bg-[#FBFAFC]")}
                 threadId={threadId}
diff --git a/frontend/src/components/workspace/artifacts/artifact-file-detail.tsx b/frontend/src/components/workspace/artifacts/artifact-file-detail.tsx
index cb0bbaa2..32417075 100644
--- a/frontend/src/components/workspace/artifacts/artifact-file-detail.tsx
+++ b/frontend/src/components/workspace/artifacts/artifact-file-detail.tsx
@@ -61,7 +61,7 @@ export function ArtifactFileDetail({
 }: {
   className?: string;
   filepath: string;
-  threadId?: string;
+  threadId: string;
 }) {
   const { t } = useI18n();
   const { artifacts, setOpen, select, fullscreen, setFullscreen } =
@@ -511,7 +511,7 @@ export function ArtifactFilePreview({
   content: string;
   language: string;
   zoom?: number;
-  threadId?: string;
+  threadId: string;
 }) {
   const zoomScale = zoom / 100;
   const normalizedContent = useMemo(() => {
diff --git a/frontend/src/components/workspace/artifacts/artifact-file-list.tsx b/frontend/src/components/workspace/artifacts/artifact-file-list.tsx
index c36d94f8..163ab44d 100644
--- a/frontend/src/components/workspace/artifacts/artifact-file-list.tsx
+++ b/frontend/src/components/workspace/artifacts/artifact-file-list.tsx
@@ -29,7 +29,7 @@ export function ArtifactFileList({
 }: {
   className?: string;
   files: string[];
-  threadId?: string;
+  threadId: string;
 }) {
   const { t } = useI18n();
   const { select: selectArtifact, setOpen } = useArtifacts();
diff --git a/frontend/src/components/workspace/chats/use-thread-chat.ts b/frontend/src/components/workspace/chats/use-thread-chat.ts
index 2e607197..eed2754d 100644
--- a/frontend/src/components/workspace/chats/use-thread-chat.ts
+++ b/frontend/src/components/workspace/chats/use-thread-chat.ts
@@ -7,7 +7,9 @@ import { resolveThreadQueryIntent } from "@/core/threads/utils";
 
 export function useThreadChat() {
   const pathname = usePathname();
-  const params = useParams<{ thread_id?: string }>();
+  const params = useParams<{ thread_id: string }>();
+  const searchParams = useSearchParams();
+  const threadIdFromSearchParams = searchParams.get("thread_id")?.trim();
   // 兜底：当 params 还未就绪时，从 pathname 解析 thread_id。
   const threadIdFromPathname = (() => {
     const parts = pathname.split("?")[0]?.split("/") ?? [];
@@ -18,8 +20,11 @@ export function useThreadChat() {
     return undefined;
   })();
   const rawPathThreadId = params?.thread_id ?? threadIdFromPathname;
+
   const isNewRoute = rawPathThreadId === "new";
-  const threadIdFromPath = isNewRoute ? undefined : rawPathThreadId;
+  const threadIdFromPathOrParams:string = isNewRoute
+    ? threadIdFromSearchParams?? params.thread_id
+    : params.thread_id;
   // console.log("[useThreadChat] pathname", pathname);
   // console.log("[useThreadChat] params.thread_id", params?.thread_id);
   // console.log("[useThreadChat] threadIdFromPathname", threadIdFromPathname);
@@ -33,10 +38,9 @@ export function useThreadChat() {
     return isValidThreadId(stored) ? stored : undefined;
   };
 
-  const searchParams = useSearchParams();
   // 读取 query 的 thread_id（先用 hook，必要时用 window 兜底）。
   const readQueryThreadId = () => {
-    const fromHook = searchParams.get("thread_id")?.trim();
+    const fromHook = threadIdFromSearchParams;
     if (isValidThreadId(fromHook)) {
       return fromHook;
     }
@@ -51,7 +55,7 @@ export function useThreadChat() {
     }
     return undefined;
   };
-  
+
   const queryThreadIdFromParams = readQueryThreadId();
   // console.log("[useThreadChat] query.thread_id", queryThreadIdFromParams);
   // 归一化：当值为 "new" 时，替换为 query 中的 thread_id（如果存在）。
@@ -65,20 +69,16 @@ export function useThreadChat() {
     [queryThreadIdFromParams],
   );
   const intent = resolveThreadQueryIntent({
-    pathThreadId: threadIdFromPath,
+    pathThreadId: threadIdFromPathOrParams,
     queryThreadId: queryThreadIdFromParams,
     isNewRoute,
   });
-  const { isNewThread: isNewRequested, showWelcomeStyle, invalidNewRoute } = intent;
-  const effectiveThreadIdFromPath =
-    invalidNewRoute
-      ? undefined
-      : normalizeThreadId(threadIdFromPath) ??
-        (isNewRoute ? undefined : readStoredThreadId());
+  const { isNewThread: isNewRequested, showWelcomeStyle } = intent;
+
   // console.log("[useThreadChat] effectiveThreadIdFromPath", effectiveThreadIdFromPath);
-  
-  const [threadId, setThreadId] = useState(() => {
-    return effectiveThreadIdFromPath ?? undefined;
+
+  const [threadId, setThreadId] = useState<string>(() => {
+    return threadIdFromPathOrParams;
   });
 
   // New session is only controlled by `/workspace/chats/new`.
@@ -91,17 +91,14 @@ export function useThreadChat() {
     }
     setIsNewThread(isNewRoute);
     // Prefer path thread id, fall back to query thread_id when path is /new.
-    setThreadId(
-      invalidNewRoute ? undefined : normalizeThreadId(threadIdFromPath),
-    );
+    setThreadId(threadIdFromPathOrParams);
   }, [
-    invalidNewRoute,
     isNewRoute,
     normalizeThreadId,
     pathname,
     searchParams,
     threadId,
-    threadIdFromPath,
+    threadIdFromPathOrParams,
   ]);
   const isMock = searchParams.get("mock") === "true";
   return {
@@ -110,7 +107,6 @@ export function useThreadChat() {
     setIsNewThread,
     isMock,
     showWelcomeStyle,
-    invalidNewRoute,
   };
 }
 
diff --git a/frontend/src/components/workspace/export-trigger.tsx b/frontend/src/components/workspace/export-trigger.tsx
index db83e19b..c6b15d9b 100644
--- a/frontend/src/components/workspace/export-trigger.tsx
+++ b/frontend/src/components/workspace/export-trigger.tsx
@@ -21,7 +21,7 @@ import type { AgentThread } from "@/core/threads/types";
 import { useThread } from "./messages/context";
 import { Tooltip } from "./tooltip";
 
-export function ExportTrigger({ threadId }: { threadId?: string }) {
+export function ExportTrigger({ threadId }: { threadId: string }) {
   const { t } = useI18n();
   const { thread } = useThread();
 
diff --git a/frontend/src/components/workspace/input-box.tsx b/frontend/src/components/workspace/input-box.tsx
index ecb32806..3b15c515 100644
--- a/frontend/src/components/workspace/input-box.tsx
+++ b/frontend/src/components/workspace/input-box.tsx
@@ -100,7 +100,7 @@ export function InputBox({
   ...props
 }: Omit<ComponentProps<typeof PromptInput>, "onSubmit"> & {
   assistantId?: string | null;
-  threadId?: string;
+  threadId: string;
   status?: ChatStatus;
   disabled?: boolean;
   context: Omit<
diff --git a/frontend/src/components/workspace/messages/context.ts b/frontend/src/components/workspace/messages/context.ts
index dede9ee8..3eea108b 100644
--- a/frontend/src/components/workspace/messages/context.ts
+++ b/frontend/src/components/workspace/messages/context.ts
@@ -5,7 +5,7 @@ import type { AgentThreadState } from "@/core/threads";
 
 export interface ThreadContextType {
   thread: UseStream<AgentThreadState>;
-  threadId?: string;
+  threadId: string;
   isMock?: boolean;
 }
 
diff --git a/frontend/src/components/workspace/messages/message-list-item.tsx b/frontend/src/components/workspace/messages/message-list-item.tsx
index 55313d3e..bde754fa 100644
--- a/frontend/src/components/workspace/messages/message-list-item.tsx
+++ b/frontend/src/components/workspace/messages/message-list-item.tsx
@@ -45,7 +45,7 @@ export function MessageListItem({
   className?: string;
   message: Message;
   isLoading?: boolean;
-  threadId?: string;
+  threadId: string;
 }) {
   const isHuman = message.type === "human";
   return (
@@ -94,7 +94,7 @@ function MessageImage({
   maxWidth = "90%",
   ...props
 }: React.ImgHTMLAttributes<HTMLImageElement> & {
-  threadId?: string;
+  threadId: string;
   maxWidth?: string;
 }) {
   if (!src) return null;
@@ -124,7 +124,7 @@ function MessageContent_({
   className?: string;
   message: Message;
   isLoading?: boolean;
-  threadId?: string;
+  threadId: string;
 }) {
   const rehypePlugins = useRehypeSplitWordsIntoSpans(isLoading);
   const isHuman = message.type === "human";
diff --git a/frontend/src/components/workspace/messages/message-list.tsx b/frontend/src/components/workspace/messages/message-list.tsx
index 1dc11543..2e8bc047 100644
--- a/frontend/src/components/workspace/messages/message-list.tsx
+++ b/frontend/src/components/workspace/messages/message-list.tsx
@@ -42,7 +42,7 @@ export function MessageList({
   scrollButtonClassName,
 }: {
   className?: string;
-  threadId?: string;
+  threadId: string;
   thread: UseStream<AgentThreadState>;
   /** When set (e.g. from onFinish), use instead of thread.messages so SSE end shows complete state. */
   messagesOverride?: Message[];
diff --git a/frontend/src/components/workspace/thread-title.tsx b/frontend/src/components/workspace/thread-title.tsx
index 35e9b57e..201b18f4 100644
--- a/frontend/src/components/workspace/thread-title.tsx
+++ b/frontend/src/components/workspace/thread-title.tsx
@@ -13,7 +13,7 @@ export function ThreadTitle({
   threadTitle,
 }: {
   className?: string;
-  threadId?: string;
+  threadId: string;
   thread?: UseStream<AgentThreadState>;
   threadTitle?: string;
 }) {
diff --git a/frontend/src/core/artifacts/hooks.ts b/frontend/src/core/artifacts/hooks.ts
index 6d875aba..78e411d3 100644
--- a/frontend/src/core/artifacts/hooks.ts
+++ b/frontend/src/core/artifacts/hooks.ts
@@ -11,7 +11,7 @@ export function useArtifactContent({
   enabled,
 }: {
   filepath: string;
-  threadId?: string;
+  threadId: string;
   enabled?: boolean;
 }) {
   const isWriteFile = useMemo(() => {
diff --git a/frontend/src/core/threads/hooks.test.ts b/frontend/src/core/threads/hooks.test.ts
index 7967f87a..3e156191 100644
--- a/frontend/src/core/threads/hooks.test.ts
+++ b/frontend/src/core/threads/hooks.test.ts
@@ -26,5 +26,4 @@ void test("prefers path thread id over query thread id when not on /new", () =>
 
   assert.equal(intent.isNewThread, false);
   assert.equal(intent.threadId, "thread-from-path");
-  assert.equal(intent.invalidNewRoute, false);
 });
diff --git a/frontend/src/core/threads/hooks.ts b/frontend/src/core/threads/hooks.ts
index 9c0a368f..d8bc08d3 100644
--- a/frontend/src/core/threads/hooks.ts
+++ b/frontend/src/core/threads/hooks.ts
@@ -29,7 +29,7 @@ export type ToolEndEvent = {
 };
 
 export type ThreadStreamOptions = {
-  threadId?: string | null | undefined;
+  threadId: string | null | undefined;
   context: LocalSettings["context"];
   createNewSession?: boolean;
   isMock?: boolean;
diff --git a/frontend/src/core/threads/utils.ts b/frontend/src/core/threads/utils.ts
index 8d8db93f..651a1420 100644
--- a/frontend/src/core/threads/utils.ts
+++ b/frontend/src/core/threads/utils.ts
@@ -12,7 +12,6 @@ export interface ThreadQueryIntent {
   threadId: string | undefined;
   isNewThread: boolean;
   showWelcomeStyle: boolean;
-  invalidNewRoute: boolean;
 }
 
 export function pathOfThread(threadId: string) {
@@ -45,8 +44,6 @@ export function resolveThreadQueryIntent({
     // 新逻辑只由路由 /workspace/chats/new 控制“新会话”
     isNewThread,
     showWelcomeStyle: isNewThread,
-    // 新逻辑下不再要求 /new 必带 query thread_id
-    invalidNewRoute: false,
   };
 }
 
diff --git a/frontend/src/hooks/use-selected-skill-listener.ts b/frontend/src/hooks/use-selected-skill-listener.ts
index bba41577..7fd6721e 100644
--- a/frontend/src/hooks/use-selected-skill-listener.ts
+++ b/frontend/src/hooks/use-selected-skill-listener.ts
@@ -19,7 +19,7 @@ interface SkillError {
 
 interface UseSelectedSkillListenerOptions {
   /** 当前会话 thread_id，用于调用 bootstrapRemoteSkill */
-  threadId?: string | null;
+  threadId: string | null;
 }
 
 interface UseSelectedSkillListenerReturn {
diff --git a/frontend/tests/e2e/support/chat-helpers.ts b/frontend/tests/e2e/support/chat-helpers.ts
index 0eaf1c25..a3b3501a 100644
--- a/frontend/tests/e2e/support/chat-helpers.ts
+++ b/frontend/tests/e2e/support/chat-helpers.ts
@@ -34,7 +34,7 @@ export function buildChatUrl({
 }: {
   pathThreadId?: string;
   xclawUsed: boolean;
-  threadId?: string;
+  threadId: string;
 }) {
   const resolvedThreadId = threadId ?? pathThreadId;
   if (!pathThreadId && !resolvedThreadId) {