diff --git a/web/static/css/style.css b/web/static/css/style.css
index 519563b9..f79dd1d7 100644
--- a/web/static/css/style.css
+++ b/web/static/css/style.css
@@ -2871,6 +2871,24 @@ header {
     background: rgba(0, 102, 255, 0.05);
 }
 
+/* Eino 多代理：主编排器 vs 子代理时间线区分 */
+.timeline-eino-role-orchestrator {
+    border-left-color: #5c6bc0 !important;
+    background: rgba(92, 107, 192, 0.09) !important;
+}
+.timeline-eino-role-sub {
+    border-left-color: #00897b !important;
+    background: rgba(0, 137, 123, 0.08) !important;
+}
+.timeline-item-iteration.timeline-eino-scope-main {
+    border-left-color: #3949ab !important;
+    background: rgba(57, 73, 171, 0.1) !important;
+}
+.timeline-item-iteration.timeline-eino-scope-sub {
+    border-left-color: #00695c !important;
+    background: rgba(0, 105, 92, 0.09) !important;
+}
+
 .timeline-item-thinking {
     border-left-color: #9c27b0;
     background: rgba(156, 39, 176, 0.05);
diff --git a/web/static/i18n/en-US.json b/web/static/i18n/en-US.json
index 48f455f0..1d76291c 100644
--- a/web/static/i18n/en-US.json
+++ b/web/static/i18n/en-US.json
@@ -147,6 +147,8 @@
     "addNewGroup": "+ New group",
     "callNumber": "Call #{{n}}",
     "iterationRound": "Iteration {{n}}",
+    "einoOrchestratorRound": "Orchestrator · round {{n}}",
+    "einoSubAgentStep": "Sub-agent {{agent}} · step {{n}}",
     "aiThinking": "AI thinking",
     "planning": "Planning",
     "toolCallsDetected": "Detected {{count}} tool call(s)",
@@ -156,6 +158,7 @@
     "knowledgeRetrieval": "Knowledge retrieval",
     "knowledgeRetrievalTag": "Knowledge retrieval",
     "error": "Error",
+    "streamNetworkErrorHint": "Connection lost ({{detail}}). A long task may still be running on the server; check running tasks at the top or refresh this conversation later.",
     "taskCancelled": "Task cancelled",
     "unknownTool": "Unknown tool",
     "einoAgentReplyTitle": "Sub-agent reply",
diff --git a/web/static/i18n/zh-CN.json b/web/static/i18n/zh-CN.json
index 434b1fa0..c1625e5c 100644
--- a/web/static/i18n/zh-CN.json
+++ b/web/static/i18n/zh-CN.json
@@ -147,6 +147,8 @@
     "addNewGroup": "+ 新增分组",
     "callNumber": "调用 #{{n}}",
     "iterationRound": "第 {{n}} 轮迭代",
+    "einoOrchestratorRound": "主代理 · 第 {{n}} 轮",
+    "einoSubAgentStep": "子代理 {{agent}} · 第 {{n}} 步",
     "aiThinking": "AI思考",
     "planning": "规划中",
     "toolCallsDetected": "检测到 {{count}} 个工具调用",
@@ -156,6 +158,7 @@
     "knowledgeRetrieval": "知识检索",
     "knowledgeRetrievalTag": "知识检索",
     "error": "错误",
+    "streamNetworkErrorHint": "连接已中断（{{detail}}）。长时间任务可能仍在后端执行，请查看顶部「运行中」任务或稍后刷新本对话。",
     "taskCancelled": "任务已取消",
     "unknownTool": "未知工具",
     "einoAgentReplyTitle": "子代理回复",
diff --git a/web/static/js/chat.js b/web/static/js/chat.js
index 16c1beae..44046180 100644
--- a/web/static/js/chat.js
+++ b/web/static/js/chat.js
@@ -361,7 +361,18 @@ async function sendMessage() {
         
     } catch (error) {
         removeMessage(progressId);
-        addMessage('system', '错误: ' + error.message);
+        const msg = error && error.message != null ? String(error.message) : String(error);
+        const isNetwork = /network|fetch|Failed to fetch|aborted|AbortError|load failed|NetworkError/i.test(msg);
+        if (isNetwork && typeof window.t === 'function') {
+            addMessage('system', window.t('chat.streamNetworkErrorHint', { detail: msg }));
+        } else if (isNetwork) {
+            addMessage('system', '连接已中断（' + msg + '）。长时间任务可能仍在后端执行，请查看顶部运行中任务或稍后刷新对话。');
+        } else {
+            addMessage('system', '错误: ' + msg);
+        }
+        if (typeof loadActiveTasks === 'function') {
+            loadActiveTasks();
+        }
         // 发送失败时，不恢复草稿，因为消息已经显示在对话框中了
     }
 }
diff --git a/web/static/js/monitor.js b/web/static/js/monitor.js
index 171f41f0..2318f9d9 100644
--- a/web/static/js/monitor.js
+++ b/web/static/js/monitor.js
@@ -96,6 +96,21 @@ function timelineAgentBracketPrefix(data) {
     return s ? ('[' + s + '] ') : '';
 }
 
+/** 主/子代理视觉区分：左边框与浅底色（与工具黄/绿状态并存时由具体项类型覆盖次要边） */
+function applyEinoTimelineRole(item, data) {
+    if (!item || !data) return;
+    const role = data.einoRole;
+    if (role === 'orchestrator' || role === 'sub') {
+        item.dataset.einoRole = role;
+        item.classList.add('timeline-eino-role-' + role);
+    }
+    const scope = data.einoScope;
+    if (scope === 'main' || scope === 'sub') {
+        item.dataset.einoScope = scope;
+        item.classList.add('timeline-eino-scope-' + scope);
+    }
+}
+
 // markdown 渲染（用于最终合并渲染；流式增量阶段用纯转义避免部分语法不稳定）
 const assistantMarkdownSanitizeConfig = {
     ALLOWED_TAGS: ['p', 'br', 'strong', 'em', 'u', 's', 'code', 'pre', 'blockquote', 'h1', 'h2', 'h3', 'h4', 'h5', 'h6', 'ul', 'ol', 'li', 'a', 'img', 'table', 'thead', 'tbody', 'tr', 'th', 'td', 'hr'],
@@ -710,15 +725,32 @@ function handleStreamEvent(event, progressElement, progressId,
                 }, 200);
             }
             break;
-        case 'iteration':
-            // 添加迭代标记（data 属性供语言切换时重算标题）
+        case 'iteration': {
+            const d = event.data || {};
+            const n = d.iteration != null ? d.iteration : 1;
+            let iterTitle;
+            if (d.einoScope === 'main') {
+                iterTitle = typeof window.t === 'function'
+                    ? window.t('chat.einoOrchestratorRound', { n: n })
+                    : ('主代理 · 第 ' + n + ' 轮');
+            } else if (d.einoScope === 'sub') {
+                const ag = d.einoAgent != null ? String(d.einoAgent).trim() : '';
+                iterTitle = typeof window.t === 'function'
+                    ? window.t('chat.einoSubAgentStep', { n: n, agent: ag })
+                    : ('子代理 · ' + ag + ' · 第 ' + n + ' 步');
+            } else {
+                iterTitle = typeof window.t === 'function'
+                    ? window.t('chat.iterationRound', { n: n })
+                    : ('第 ' + n + ' 轮迭代');
+            }
             addTimelineItem(timeline, 'iteration', {
-                title: typeof window.t === 'function' ? window.t('chat.iterationRound', { n: event.data?.iteration || 1 }) : '第 ' + (event.data?.iteration || 1) + ' 轮迭代',
+                title: iterTitle,
                 message: event.message,
                 data: event.data,
-                iterationN: event.data?.iteration || 1
+                iterationN: n
             });
             break;
+        }
             
         case 'thinking_stream_start': {
             const d = event.data || {};
@@ -1381,6 +1413,9 @@ function addTimelineItem(timeline, type, options) {
     if (type === 'iteration') {
         const n = options.iterationN != null ? options.iterationN : (options.data && options.data.iteration != null ? options.data.iteration : 1);
         item.dataset.iterationN = String(n);
+        if (options.data && options.data.einoScope) {
+            item.dataset.einoScope = String(options.data.einoScope);
+        }
     }
     if (type === 'progress' && options.message) {
         item.dataset.progressMessage = options.message;
@@ -1493,6 +1528,9 @@ function addTimelineItem(timeline, type, options) {
     }
     
     item.innerHTML = content;
+    if (options.data) {
+        applyEinoTimelineRole(item, options.data);
+    }
     timeline.appendChild(item);
     
     // 自动展开详情
@@ -2298,7 +2336,15 @@ function refreshProgressAndTimelineI18n() {
         const ap = (item.dataset.einoAgent && item.dataset.einoAgent !== '') ? ('[' + item.dataset.einoAgent + '] ') : '';
         if (type === 'iteration' && item.dataset.iterationN) {
             const n = parseInt(item.dataset.iterationN, 10) || 1;
-            titleSpan.textContent = ap + _t('chat.iterationRound', { n: n });
+            const scope = item.dataset.einoScope;
+            if (scope === 'main') {
+                titleSpan.textContent = _t('chat.einoOrchestratorRound', { n: n });
+            } else if (scope === 'sub') {
+                const agent = item.dataset.einoAgent || '';
+                titleSpan.textContent = _t('chat.einoSubAgentStep', { n: n, agent: agent });
+            } else {
+                titleSpan.textContent = ap + _t('chat.iterationRound', { n: n });
+            }
         } else if (type === 'thinking') {
             titleSpan.textContent = ap + '\uD83E\uDD14 ' + _t('chat.aiThinking');
         } else if (type === 'tool_calls_detected' && item.dataset.toolCallsCount != null) {