fix(chat): separate merged output segments

docs/chat-chain-changes/2026-11-05-output-separators.md

@@ -0,0 +1,9 @@
+---
+date: 2026-11-05
+pr: pending
+feature: Separate merged agent output
+impact: Individual assistant messages within one run remain in one bubble but have visual dividers; the run completion marker is closer to the message. Stored text and chat events are unchanged.
+---
+
+Message boundaries are retained as display-only segments. The combined text
+used for copying and speech remains unchanged.

packages/client/src/components/hermes/chat/MessageItem.vue

@@ -228,6 +228,14 @@ const parsedThinking = computed(() =>
   parseThinking(props.message.content || "", { streaming: !!props.message.isStreaming }),
 );
 
+const segmentBoundary = '\uE000hermes-output-boundary\uE001';
+const assistantBodySegments = computed(() => {
+  const segments = props.message.contentSegments;
+  if (!segments || segments.length < 2) return parsedThinking.value.body ? [parsedThinking.value.body] : [];
+  const parsed = parseThinking(segments.join(segmentBoundary), { streaming: !!props.message.isStreaming });
+  return parsed.body.split(segmentBoundary).filter(segment => segment.trim());
+});
+
 // 优先使用来自 reasoning 字段/事件的思考文本；否则回退到从 content 解析的 <think> 标签。
 // 若两者共存，则拼接展示（罕见，但保持信息不丢）。
 const hasReasoningField = computed(() => !!(props.message.reasoning && props.message.reasoning.length > 0));
@@ -1111,11 +1119,12 @@ onBeforeUnmount(() => {
                 <MarkdownRenderer :content="thinkingFullText" />
               </div>
             </div>
-            <MarkdownRenderer
-              v-if="parsedThinking.body && message.role === 'assistant'"
-              :content="parsedThinking.body"
-              :heading-id-prefix="effectiveHeadingIdPrefix"
-            />
+            <template v-if="message.role === 'assistant'">
+              <template v-for="(segment, index) in assistantBodySegments" :key="index">
+                <hr v-if="index > 0" class="assistant-segment-divider" />
+                <MarkdownRenderer :content="segment" :heading-id-prefix="index ? `${effectiveHeadingIdPrefix}-${index}` : effectiveHeadingIdPrefix" />
+              </template>
+            </template>
 
             <!-- Render user message content -->
             <template v-if="message.role === 'user'">
@@ -1160,7 +1169,7 @@ onBeforeUnmount(() => {
 
             <!-- Render assistant message content -->
             <MarkdownRenderer
-              v-if="message.role === 'assistant' && message.content && !parsedThinking.body"
+              v-if="message.role === 'assistant' && message.content && !assistantBodySegments.length"
               :content="message.content"
               :heading-id-prefix="effectiveHeadingIdPrefix"
             />
@@ -1647,6 +1656,12 @@ onBeforeUnmount(() => {
   }
 }
 
+.assistant-segment-divider {
+  border: 0;
+  border-top: 1px solid var(--color-border-2);
+  margin: 12px 0;
+}
+
 .message-meta {
   display: flex;
   align-items: center;

packages/client/src/components/hermes/chat/MessageList.vue

@@ -910,7 +910,7 @@ defineExpose({
 }
 
 .run-end {
-  margin: 20px auto;
+  margin: -12px auto 0;
   text-align: center;
   color: var(--color-text-3);
   font-size: 12px;

packages/client/src/components/hermes/chat/groupRunMessages.ts

@@ -14,6 +14,7 @@ export function groupRunMessages(messages: Message[], runActive: boolean): Messa
       result.push({
         ...first,
         toolMessages: tools.length ? tools : undefined,
+        contentSegments: assistants.map(m => m.content).filter(text => text.trim()),
         id: assistants[assistants.length - 1].id,
         content: assistants.map(m => m.content).filter(text => text.trim()).join('\n\n'),
         reasoning: assistants.map(m => m.reasoning).filter(Boolean).join('\n\n') || undefined,

packages/client/src/stores/hermes/chat.ts

@@ -65,6 +65,7 @@ export interface Message {
   queued?: boolean
   systemType?: 'command' | 'error' | 'fork-divider' | 'run-end' | 'tool-group'
   toolMessages?: Message[]
+  contentSegments?: string[]
   commandAction?: string
   commandData?: Record<string, unknown>
   finishReason?: string | null

tests/client/chat-group-run-messages.test.ts

@@ -11,6 +11,7 @@ describe('groupRunMessages', () => {
     expect(active.map(m => m.role)).toEqual(['user', 'assistant'])
     expect(active[1].toolMessages).toEqual([input[2]])
     expect(active[1]).toMatchObject({ id: 'b', content: 'first\n\nsecond' })
+    expect(active[1].contentSegments).toEqual(['first', 'second'])
     const finished = groupRunMessages(input, false)
     expect(finished.at(-1)?.systemType).toBe('run-end')
   })

tests/e2e/chat-rendering-smoke.spec.ts

@@ -57,6 +57,7 @@ test('streams a run and renders markdown, code, math and mermaid without leaking
   }, sessionId)
 
   const bubble = page.locator('.message').last()
+  await expect(bubble.locator('.assistant-segment-divider')).toHaveCount(0)
   await expect(bubble.locator('strong')).toHaveText('bold')
   await expect(bubble.locator('code')).toHaveCount(2)
   await expect(bubble.locator('.katex')).toHaveCount(1)
@@ -132,11 +133,18 @@ test('groups assistant output across tool calls until the run ends', async ({ pa
   await expect(assistant).toHaveCount(1)
   await expect(assistant).toContainText('First update')
   await expect(assistant).toContainText('Second update')
+  await expect(assistant.locator('.assistant-segment-divider')).toHaveCount(1)
+  await expect(assistant.locator('.message-bubble')).toHaveCount(1)
   await expect(page.locator('.run-end')).toHaveCount(0)
   await page.evaluate((sid) => {
     (window as any).__PW_CHAT_SOCKET__.latest.__trigger('run.completed', { event: 'run.completed', session_id: sid, run_id: 'grouped-run' })
   }, sessionId)
   await expect(page.locator('.run-end')).toHaveText('Run output ended')
+  await expect.poll(async () => {
+    const bubble = await assistant.locator('.message-bubble').boundingBox()
+    const end = await page.locator('.run-end').boundingBox()
+    return bubble && end ? end.y - (bubble.y + bubble.height) : Infinity
+  }).toBeLessThan(50)
 })
 
 test('shows agent activity under its own avatar before the answer', async ({ page }) => {