diff --git a/web/hwlab-cloud-web/app-trace.test.ts b/web/hwlab-cloud-web/app-trace.test.ts
index 1372529a..c0ccaf7b 100644
--- a/web/hwlab-cloud-web/app-trace.test.ts
+++ b/web/hwlab-cloud-web/app-trace.test.ts
@@ -290,6 +290,67 @@ test("trace display rows render non-noise AgentRun tool item details", () => {
   assert.match(text, /当前可见 2 个 device-pod/u);
 });
 
+test("trace display rows collapse repeated AgentRun assistant snapshots and notification replay", () => {
+  const events = [
+    event(1, "agentrun:request:accepted", { message: "accepted" }),
+    event(2, "agentrun:assistant:message", {
+      type: "assistant",
+      status: "running",
+      itemId: "msg_progress_1",
+      message: "我尝试拉取这个 issue 的内容。"
+    }),
+    commandEvent(3, "item/commandExecution:completed", {
+      itemId: "cmd_issue_read",
+      command: "gh api repos/pikasTech/agentrun/issues/42",
+      status: "completed",
+      exitCode: 0,
+      stdoutSummary: "success=true"
+    }),
+    event(4, "agentrun:assistant:message", {
+      type: "assistant",
+      status: "running",
+      itemId: "msg_summary",
+      message: "已经拉到完整内容。Issue 元信息。"
+    }),
+    event(5, "agentrun:assistant:message", {
+      type: "assistant",
+      status: "running",
+      itemId: "msg_summary",
+      message: "已经拉到完整内容。Issue 元信息。6 条评论时间线。"
+    }),
+    event(6, "agentrun:assistant:message", {
+      type: "assistant",
+      status: "running",
+      itemId: "msg_summary",
+      message: "已经拉到完整内容。Issue 元信息。6 条评论时间线。验收完成。"
+    }),
+    event(7, "agentrun:backend:turn/completed", { message: "turn/completed" }),
+    event(8, "agentrun:assistant:message", {
+      type: "assistant",
+      status: "running",
+      itemId: "msg_progress_1_replay",
+      message: "我尝试拉取这个 issue 的内容。"
+    }),
+    event(9, "agentrun:assistant:message", {
+      type: "assistant",
+      status: "running",
+      itemId: "msg_summary",
+      message: "已经拉到完整内容。Issue 元信息。6 条评论时间线。验收完成。"
+    }),
+    event(10, "agentrun:terminal:completed", { type: "result", terminal: true, status: "completed" })
+  ];
+
+  const rows = traceDisplayRows({ traceId: "trc_issue_720_duplicate", events }, events);
+  const assistantRows = rows.filter((row) => /助手/u.test(row.header));
+  const text = rows.map((row) => `${row.header}\n${row.body ?? ""}`).join("\n---\n");
+
+  assert.equal(assistantRows.length, 2);
+  assert.deepEqual(assistantRows.map((row) => row.seq), [2, 6]);
+  assert.equal(matchCount(text, /我尝试拉取这个 issue 的内容/u), 1);
+  assert.equal(matchCount(text, /已经拉到完整内容/u), 1);
+  assert.match(text, /验收完成/u);
+});
+
 function traceEvents() {
   return [
     event(1, "request:accepted", { promptSummary: "请检查 trace" }),
@@ -341,3 +402,8 @@ function event(seq, label, fields = {}) {
     ...fields
   };
 }
+
+function matchCount(text, pattern) {
+  const flags = pattern.flags.includes("g") ? pattern.flags : `${pattern.flags}g`;
+  return [...String(text ?? "").matchAll(new RegExp(pattern.source, flags))].length;
+}
diff --git a/web/hwlab-cloud-web/app-trace.ts b/web/hwlab-cloud-web/app-trace.ts
index 296a310e..a956904a 100644
--- a/web/hwlab-cloud-web/app-trace.ts
+++ b/web/hwlab-cloud-web/app-trace.ts
@@ -291,6 +291,8 @@ export function traceDisplayRows(trace, events) {
   const requestEvent = tracePrimaryRequestEvent(events);
   const hasTerminalAssistant = events.some((event) => isTerminalAssistantTraceEvent(event));
   const terminalAssistantOnly = hasTerminalAssistant && !events.some((event) => isCommandExecutionTraceEvent(event));
+  const latestAssistantByIdentity = traceLatestAssistantEventsByIdentity(events);
+  const renderedAssistantTextKeys = new Set();
   const renderedCommands = new Set();
   const renderedToolCalls = new Set();
   let requestRendered = false;
@@ -323,9 +325,17 @@ export function traceDisplayRows(trace, events) {
       continue;
     }
     if (isAssistantMessageTraceEvent(event)) {
-      const row = traceAssistantSummaryRow(trace, event, assistantIndex);
-      assistantIndex += 1;
-      if (row) rows.push(row);
+      const assistantIdentity = traceAssistantMessageIdentity(event);
+      if (assistantIdentity && latestAssistantByIdentity.get(assistantIdentity) !== event) continue;
+      const assistantText = traceAssistantTextForEvent(trace, event, assistantIndex);
+      const assistantTextKey = traceAssistantComparableText(assistantText);
+      if (!isTerminalAssistantTraceEvent(event) && assistantTextKey && renderedAssistantTextKeys.has(assistantTextKey)) continue;
+      const row = traceAssistantSummaryRow(trace, event, assistantIndex, assistantText);
+      if (row) {
+        rows.push(row);
+        assistantIndex += 1;
+        if (assistantTextKey) renderedAssistantTextKeys.add(assistantTextKey);
+      }
       continue;
     }
     if (isRequestTraceEvent(event)) {
@@ -416,6 +426,38 @@ function traceGenericToolCallGroups(events) {
   return groups;
 }
 
+function traceLatestAssistantEventsByIdentity(events) {
+  const latest = new Map();
+  const firstCompletionIndex = events.findIndex((event) => isCompletionTraceEvent(event));
+  for (const event of events) {
+    if (!isAssistantMessageTraceEvent(event)) continue;
+    const identity = traceAssistantMessageIdentity(event);
+    if (!identity) continue;
+    const previous = latest.get(identity);
+    if (!previous || traceAssistantEventShouldReplace(previous, event, firstCompletionIndex, events)) latest.set(identity, event);
+  }
+  return latest;
+}
+
+function traceAssistantEventShouldReplace(previous, event, firstCompletionIndex, events) {
+  if (isTerminalAssistantTraceEvent(event)) return true;
+  if (isTerminalAssistantTraceEvent(previous)) return false;
+  const previousAfterCompletion = traceEventAfterIndex(previous, firstCompletionIndex, events);
+  const eventAfterCompletion = traceEventAfterIndex(event, firstCompletionIndex, events);
+  if (previousAfterCompletion !== eventAfterCompletion) return previousAfterCompletion && !eventAfterCompletion;
+  return true;
+}
+
+function traceEventAfterIndex(event, index, events) {
+  if (index < 0) return false;
+  const eventIndex = events.findIndex((item) => item === event || (item?.seq !== undefined && item.seq === event?.seq));
+  return eventIndex > index;
+}
+
+function traceAssistantMessageIdentity(event) {
+  return traceNonEmptyString(event?.itemId ?? event?.messageId ?? event?.id);
+}
+
 function traceCommandGroupKey(event, fallback = null) {
   return traceNonEmptyString(event?.itemId ?? event?.callId ?? event?.commandId ?? event?.id) || fallback || `cmd:${event?.seq ?? event?.createdAt ?? Math.random()}`;
 }
@@ -689,9 +731,9 @@ function traceCompletionSummaryRow(trace, event) {
   };
 }
 
-function traceAssistantSummaryRow(trace, event, index = 0) {
+function traceAssistantSummaryRow(trace, event, index = 0, textOverride = undefined) {
   const terminal = isTerminalAssistantTraceEvent(event);
-  const text = traceAssistantTextForEvent(trace, event, index);
+  const text = textOverride === undefined ? traceAssistantTextForEvent(trace, event, index) : textOverride;
   if (!text && !terminal && traceHasLaterTerminalAssistant(trace, event)) return null;
   const elapsed = formatTraceDuration(traceRelativeMs(trace, event));
   return {