diff --git a/frontend/app/components/assistant-ui/thread-list.tsx b/frontend/app/components/assistant-ui/thread-list.tsx
index 0e33ae7..4bcbeda 100644
--- a/frontend/app/components/assistant-ui/thread-list.tsx
+++ b/frontend/app/components/assistant-ui/thread-list.tsx
@@ -129,6 +129,9 @@ type ClawReplaySnapshot = SessionReplaySnapshot<
 	ClawRunStatus
 >;
 
+const SESSION_BADGE_POLL_INTERVAL_MS = 2000;
+const MAX_SESSION_BADGE_POLL_COUNT = 80;
+
 function replaySessionSnapshot(
 	replaySession: ReplaySessionFn,
 	sessionId: string,
@@ -359,6 +362,7 @@ const ClawSessionList: FC = () => {
 	const renameInputRef = useRef<HTMLInputElement | null>(null);
 	const openRequestRef = useRef(0);
 	const openAbortRef = useRef<AbortController | null>(null);
+	const sessionBadges = useSessionRunBadges(sessions, activeSessionId);
 
 	useEffect(() => {
 		setActiveSessionId(readActiveSessionId());
@@ -423,6 +427,7 @@ const ClawSessionList: FC = () => {
 	};
 
 	const openSession = async (sessionId: string) => {
+		sessionBadges.markRead(sessionId);
 		const requestId = openRequestRef.current + 1;
 		openRequestRef.current = requestId;
 		openAbortRef.current?.abort();
@@ -473,6 +478,7 @@ const ClawSessionList: FC = () => {
 				{sessions.map((session) => {
 					const active = activeSessionId === session.session_id;
 					const loading = loadingSessionId === session.session_id;
+					const badge = sessionBadges.bySessionId.get(session.session_id);
 					return (
 						<div
 							key={`claw-session-${session.session_id}-${session.modified_at}`}
@@ -526,6 +532,10 @@ const ClawSessionList: FC = () => {
 									</span>
 								</button>
 							)}
+							<SessionRunBadge
+								running={badge?.running === true}
+								unread={badge?.unread === true}
+							/>
 							<button
 								type="button"
 								className="aui-thread-list-item-more mr-2 flex size-7 shrink-0 items-center justify-center rounded-md p-0 text-muted-foreground opacity-0 transition-opacity hover:bg-accent hover:text-foreground group-hover:opacity-100 data-[busy=true]:opacity-100 data-[open=true]:bg-accent data-[open=true]:opacity-100"
@@ -601,6 +611,137 @@ const ClawSessionList: FC = () => {
 	);
 };
 
+function useSessionRunBadges(
+	sessions: ClawSession[],
+	activeSessionId: string | null,
+) {
+	const [runningIds, setRunningIds] = useState<Set<string>>(() => new Set());
+	const [unreadIds, setUnreadIds] = useState<Set<string>>(() => new Set());
+	const previousRunningIdsRef = useRef<Set<string>>(new Set());
+
+	useEffect(() => {
+		if (!activeSessionId) return;
+		setUnreadIds((current) => {
+			if (!current.has(activeSessionId)) return current;
+			const next = new Set(current);
+			next.delete(activeSessionId);
+			return next;
+		});
+	}, [activeSessionId]);
+
+	useEffect(() => {
+		const polledSessionIds = sessions
+			.slice(0, MAX_SESSION_BADGE_POLL_COUNT)
+			.map((session) => session.session_id);
+		const knownSessionIds = new Set(polledSessionIds);
+		if (polledSessionIds.length === 0) {
+			setRunningIds(new Set());
+			setUnreadIds(new Set());
+			previousRunningIdsRef.current = new Set();
+			return;
+		}
+		let cancelled = false;
+
+		async function refreshBadges() {
+			const results = await Promise.allSettled(
+				polledSessionIds.map(async (sessionId) => ({
+					sessionId,
+					status: await fetchLatestRunStatus(sessionId),
+				})),
+			);
+			if (cancelled) return;
+
+			const nextRunningIds = new Set<string>();
+			const completedSessionIds: string[] = [];
+			for (const result of results) {
+				if (result.status !== "fulfilled") continue;
+				const { sessionId, status } = result.value;
+				if (isActiveRunStatus(status)) {
+					nextRunningIds.add(sessionId);
+				} else if (previousRunningIdsRef.current.has(sessionId)) {
+					completedSessionIds.push(sessionId);
+				}
+			}
+
+			setRunningIds(nextRunningIds);
+			setUnreadIds((current) => {
+				const next = new Set(
+					[...current].filter((sessionId) => knownSessionIds.has(sessionId)),
+				);
+				for (const sessionId of completedSessionIds) {
+					if (sessionId !== activeSessionId) {
+						next.add(sessionId);
+					}
+				}
+				if (activeSessionId) next.delete(activeSessionId);
+				return next;
+			});
+			previousRunningIdsRef.current = nextRunningIds;
+		}
+
+		void refreshBadges();
+		const interval = window.setInterval(
+			refreshBadges,
+			SESSION_BADGE_POLL_INTERVAL_MS,
+		);
+		window.addEventListener("claw-sessions-changed", refreshBadges);
+		return () => {
+			cancelled = true;
+			window.clearInterval(interval);
+			window.removeEventListener("claw-sessions-changed", refreshBadges);
+		};
+	}, [sessions, activeSessionId]);
+
+	const bySessionId = new Map<string, { running: boolean; unread: boolean }>();
+	for (const session of sessions) {
+		bySessionId.set(session.session_id, {
+			running: runningIds.has(session.session_id),
+			unread: unreadIds.has(session.session_id),
+		});
+	}
+
+	const markRead = (sessionId: string) => {
+		setUnreadIds((current) => {
+			if (!current.has(sessionId)) return current;
+			const next = new Set(current);
+			next.delete(sessionId);
+			return next;
+		});
+	};
+
+	return { bySessionId, markRead };
+}
+
+function SessionRunBadge({
+	running,
+	unread,
+}: {
+	running: boolean;
+	unread: boolean;
+}) {
+	if (running) {
+		return (
+			<span
+				className="flex size-5 shrink-0 items-center justify-center text-muted-foreground"
+				title="运行中"
+			>
+				<Loader2Icon className="size-3.5 animate-spin" />
+			</span>
+		);
+	}
+	if (unread) {
+		return (
+			<span
+				className="flex size-5 shrink-0 items-center justify-center"
+				title="已完成，未查看"
+			>
+				<span className="size-2 rounded-full bg-sky-300" />
+			</span>
+		);
+	}
+	return <span aria-hidden="true" className="size-5 shrink-0" />;
+}
+
 function dedupeSessions(payload: unknown[]) {
 	const byId = new Map<string, ClawSession>();
 	for (const item of payload) {