diff --git a/apps/desktop/main/worker/workerManager.ts b/apps/desktop/main/worker/workerManager.ts
index 42ceb62c..74de1897 100644
--- a/apps/desktop/main/worker/workerManager.ts
+++ b/apps/desktop/main/worker/workerManager.ts
@@ -996,6 +996,8 @@ export interface ChatSessionItem {
   endTs: number
   messageCount: number
   firstMessageId: number
+  summary?: string | null
+  summaryMessageCount?: number | null
 }
 
 /**
diff --git a/packages/core/src/query/__tests__/session-index.test.ts b/packages/core/src/query/__tests__/session-index.test.ts
index 758182e0..d224c5c8 100644
--- a/packages/core/src/query/__tests__/session-index.test.ts
+++ b/packages/core/src/query/__tests__/session-index.test.ts
@@ -18,6 +18,7 @@ import {
   getChatSessionList,
   getSegmentSummary,
   saveSegmentSummary,
+  loadSegmentMessages,
   updateSessionGapThreshold,
   clearSessionIndex,
   generateSessionIndex,
@@ -85,7 +86,8 @@ function createSqliteDb(): TestSqliteDb {
       end_ts INTEGER NOT NULL,
       message_count INTEGER NOT NULL,
       is_manual INTEGER DEFAULT 0,
-      summary TEXT
+      summary TEXT,
+      summary_message_count INTEGER
     );
     CREATE TABLE message_context (
       message_id INTEGER NOT NULL,
@@ -276,6 +278,53 @@ describe('getSegmentSummary / saveSegmentSummary', () => {
     saveSegmentSummary(db, 1, 'Test summary')
     assert.equal(getSegmentSummary(db, 1), 'Test summary')
   })
+
+  it('keeps an appended summary visible but treats it as stale', () => {
+    const db = createSqliteDb()
+    seedMessages(db, [{ id: 1, ts: 1000 }])
+    generateSessionIndex(db, 2000)
+    saveSegmentSummary(db, 1, 'Summary before append')
+
+    assert.equal(getSegmentSummary(db, 1), 'Summary before append')
+    seedMessages(db, [{ id: 2, ts: 1500 }])
+    generateIncrementalSessionIndex(db, 2000)
+
+    assert.equal(getSegmentSummary(db, 1), null)
+    assert.deepEqual(getChatSessionList(db)[0], {
+      id: 1,
+      startTs: 1000,
+      endTs: 1500,
+      messageCount: 2,
+      summary: 'Summary before append',
+      summaryMessageCount: 1,
+      firstMessageId: 1,
+    })
+  })
+})
+
+describe('loadSegmentMessages', () => {
+  it('loads every message for summary generation instead of truncating at 500', () => {
+    const db = createSqliteDb()
+    db.exec(`
+      ALTER TABLE message ADD COLUMN sender_id INTEGER;
+      ALTER TABLE message ADD COLUMN content TEXT;
+      CREATE TABLE member (
+        id INTEGER PRIMARY KEY,
+        platform_id TEXT NOT NULL,
+        account_name TEXT,
+        group_nickname TEXT
+      );
+      INSERT INTO member (id, platform_id, account_name) VALUES (1, 'alice', 'Alice');
+    `)
+
+    const insertMessage = db.prepare('INSERT INTO message (id, ts, sender_id, content) VALUES (?, ?, 1, ?)')
+    for (let id = 1; id <= 600; id++) insertMessage.run(id, 1000 + id, `message-${id}`)
+    generateSessionIndex(db, 2000)
+
+    const messages = loadSegmentMessages(db, 1)
+    assert.equal(messages?.length, 600)
+    assert.equal(messages?.[599]?.content, 'message-600')
+  })
 })
 
 describe('updateSessionGapThreshold', () => {
diff --git a/packages/core/src/query/__tests__/session-queries.test.ts b/packages/core/src/query/__tests__/session-queries.test.ts
index 0c3b8ad8..c7392725 100644
--- a/packages/core/src/query/__tests__/session-queries.test.ts
+++ b/packages/core/src/query/__tests__/session-queries.test.ts
@@ -56,10 +56,10 @@ function createSessionDb(): SqliteTestAdapter {
       (1, 1, 100, 0, 'one', 'pm-1'),
       (2, 1, 300, 0, 'three', 'pm-3'),
       (3, 2, 200, 0, 'two', NULL);
-    INSERT INTO segment (start_ts, end_ts, message_count, summary) VALUES
-      (100, 150, 1, 'summary one'),
-      (200, 250, 1, NULL),
-      (300, 350, 1, 'summary two');
+    INSERT INTO segment (start_ts, end_ts, message_count, summary, summary_message_count) VALUES
+      (100, 150, 1, 'summary one', 1),
+      (200, 250, 1, NULL, NULL),
+      (300, 350, 1, 'summary two', 1);
   `)
   return db
 }
diff --git a/packages/core/src/query/session-queries.ts b/packages/core/src/query/session-queries.ts
index ed3482c5..b73473f0 100644
--- a/packages/core/src/query/session-queries.ts
+++ b/packages/core/src/query/session-queries.ts
@@ -95,9 +95,14 @@ export function getSessionInfo(db: DatabaseAdapter): CoreSessionInfo | null {
  */
 export function getSummaryCount(db: DatabaseAdapter): number {
   if (!hasTable(db, 'segment')) return 0
-  const row = db.prepare("SELECT COUNT(*) as count FROM segment WHERE summary IS NOT NULL AND summary != ''").get() as
-    | { count: number }
-    | undefined
+  const row = db
+    .prepare(
+      `SELECT COUNT(*) as count
+       FROM segment
+       WHERE summary IS NOT NULL AND summary != ''
+         AND summary_message_count = message_count`
+    )
+    .get() as { count: number } | undefined
   return row?.count ?? 0
 }
 
@@ -320,6 +325,7 @@ export function getSegmentSummaries(
            cs.message_count as messageCount, cs.summary
     FROM segment cs
     WHERE cs.summary IS NOT NULL AND cs.summary != ''
+      AND cs.summary_message_count = cs.message_count
   `
   const params: unknown[] = []
 
@@ -388,6 +394,8 @@ export interface ChatSessionItem {
   messageCount: number
   firstMessageId: number
   summary?: string | null
+  /** Number of messages covered when the summary was generated. Null means legacy/unknown coverage. */
+  summaryMessageCount?: number | null
 }
 
 export interface SessionIndexStats {
@@ -449,6 +457,7 @@ export function getSessionsByTimeRange(db: DatabaseAdapter, startTs: number, end
         `SELECT
           id, start_ts as startTs, end_ts as endTs,
           message_count as messageCount, summary,
+          summary_message_count as summaryMessageCount,
           (SELECT mc.message_id FROM message_context mc
            JOIN message first_msg ON first_msg.id = mc.message_id
            WHERE mc.segment_id = cs.id ORDER BY first_msg.ts ASC, first_msg.id ASC LIMIT 1) as firstMessageId
@@ -473,6 +482,7 @@ export function getRecentChatSessions(db: DatabaseAdapter, limit: number): ChatS
         `SELECT
           id, start_ts as startTs, end_ts as endTs,
           message_count as messageCount, summary,
+          summary_message_count as summaryMessageCount,
           (SELECT mc.message_id FROM message_context mc
            JOIN message first_msg ON first_msg.id = mc.message_id
            WHERE mc.segment_id = cs.id ORDER BY first_msg.ts ASC, first_msg.id ASC LIMIT 1) as firstMessageId
@@ -500,6 +510,7 @@ export function getChatSessionList(db: DatabaseAdapter): ChatSessionItem[] {
           cs.end_ts as endTs,
           cs.message_count as messageCount,
           cs.summary,
+          cs.summary_message_count as summaryMessageCount,
           (SELECT mc.message_id FROM message_context mc
            JOIN message first_msg ON first_msg.id = mc.message_id
            WHERE mc.segment_id = cs.id ORDER BY first_msg.ts ASC, first_msg.id ASC LIMIT 1) as firstMessageId
@@ -518,22 +529,24 @@ export function getChatSessionList(db: DatabaseAdapter): ChatSessionItem[] {
 export function loadSegmentMessages(
   db: DatabaseAdapter,
   segmentId: number,
-  limit: number = 500
+  limit?: number
 ): Array<{ senderName: string; content: string | null }> | null {
   try {
-    return db
-      .prepare(
-        `SELECT
+    const limitClause = limit === undefined ? '' : '\n        LIMIT ?'
+    const statement = db.prepare(
+      `SELECT
           COALESCE(mb.group_nickname, mb.account_name, mb.platform_id) as senderName,
           m.content
         FROM message_context mc
         JOIN message m ON m.id = mc.message_id
         JOIN member mb ON mb.id = m.sender_id
         WHERE mc.segment_id = ?
-        ORDER BY m.ts ASC
-        LIMIT ?`
-      )
-      .all(segmentId, limit) as unknown as Array<{ senderName: string; content: string | null }>
+        ORDER BY m.ts ASC, m.id ASC${limitClause}`
+    )
+    return statement.all(...(limit === undefined ? [segmentId] : [segmentId, limit])) as unknown as Array<{
+      senderName: string
+      content: string | null
+    }>
   } catch {
     return null
   }
@@ -544,10 +557,15 @@ export function loadSegmentMessages(
  */
 export function getSegmentSummary(db: DatabaseAdapter, segmentId: number): string | null {
   try {
-    const row = db.prepare('SELECT summary FROM segment WHERE id = ?').get(segmentId) as
-      | { summary: string | null }
+    const row = db
+      .prepare(
+        'SELECT summary, summary_message_count as summaryMessageCount, message_count as messageCount FROM segment WHERE id = ?'
+      )
+      .get(segmentId) as
+      | { summary: string | null; summaryMessageCount: number | null; messageCount: number }
       | undefined
-    return row?.summary ?? null
+    if (!row?.summary || row.summaryMessageCount !== row.messageCount) return null
+    return row.summary
   } catch {
     return null
   }
@@ -557,7 +575,10 @@ export function getSegmentSummary(db: DatabaseAdapter, segmentId: number): strin
  * Save summary text for a chat session.
  */
 export function saveSegmentSummary(db: DatabaseAdapter, segmentId: number, summary: string): void {
-  db.prepare('UPDATE segment SET summary = ? WHERE id = ?').run(summary, segmentId)
+  db.prepare('UPDATE segment SET summary = ?, summary_message_count = message_count WHERE id = ?').run(
+    summary,
+    segmentId
+  )
 }
 
 /**
diff --git a/packages/core/src/schema/tables.ts b/packages/core/src/schema/tables.ts
index 4122b6cd..ffb10d84 100644
--- a/packages/core/src/schema/tables.ts
+++ b/packages/core/src/schema/tables.ts
@@ -4,11 +4,11 @@
  * 所有 CREATE TABLE / INDEX 语句的单一事实来源。
  * 新建数据库时使用完整 Schema，现有数据库通过迁移脚本演进。
  *
- * 当前 Schema 版本：9
+ * 当前 Schema 版本：10
  */
 
 /** 当前 Schema 版本（最新迁移的版本号） */
-export const CURRENT_SCHEMA_VERSION = 9
+export const CURRENT_SCHEMA_VERSION = 10
 
 /**
  * Table DDL only (no indexes). Used by bulk-import workflows that defer
@@ -66,7 +66,8 @@ export const CHAT_DB_TABLES = `
     end_ts INTEGER NOT NULL,
     message_count INTEGER DEFAULT 0,
     is_manual INTEGER DEFAULT 0,
-    summary TEXT
+    summary TEXT,
+    summary_message_count INTEGER
   );
 
   CREATE TABLE IF NOT EXISTS message_context (
diff --git a/packages/node-runtime/src/database-manager.test.ts b/packages/node-runtime/src/database-manager.test.ts
index 19f84090..0efd58db 100644
--- a/packages/node-runtime/src/database-manager.test.ts
+++ b/packages/node-runtime/src/database-manager.test.ts
@@ -244,6 +244,61 @@ test('open safely upgrades a v8 session that has no FTS table', () => {
   manager.closeAll()
 })
 
+test('open adds summary coverage metadata without trusting legacy summaries', () => {
+  const root = makeTempDir()
+  const dbDir = path.join(root, 'data', 'databases')
+  fs.mkdirSync(dbDir, { recursive: true })
+  const dbPath = path.join(dbDir, 'v9-summary-coverage.db')
+
+  const rawDb = new Database(dbPath, { nativeBinding })
+  rawDb.exec(`
+    CREATE TABLE meta (
+      name TEXT NOT NULL,
+      platform TEXT NOT NULL,
+      type TEXT NOT NULL,
+      imported_at INTEGER NOT NULL,
+      schema_version INTEGER DEFAULT 9
+    );
+    INSERT INTO meta (name, platform, type, imported_at, schema_version)
+    VALUES ('V9 Summary', 'qq', 'group', 1000, 9);
+
+    CREATE TABLE member (
+      id INTEGER PRIMARY KEY AUTOINCREMENT,
+      platform_id TEXT NOT NULL UNIQUE
+    );
+    CREATE TABLE message (
+      id INTEGER PRIMARY KEY AUTOINCREMENT,
+      sender_id INTEGER NOT NULL,
+      ts INTEGER NOT NULL,
+      type INTEGER NOT NULL
+    );
+
+    CREATE TABLE segment (
+      id INTEGER PRIMARY KEY AUTOINCREMENT,
+      start_ts INTEGER NOT NULL,
+      end_ts INTEGER NOT NULL,
+      message_count INTEGER DEFAULT 0,
+      is_manual INTEGER DEFAULT 0,
+      summary TEXT
+    );
+    INSERT INTO segment (start_ts, end_ts, message_count, summary)
+    VALUES (1000, 1100, 2, 'legacy summary');
+  `)
+  rawDb.close()
+
+  const manager = new DatabaseManager(createPathProvider(root), { nativeBinding, allowMissingRuntimeForTests: true })
+  const db = manager.open('v9-summary-coverage')
+  assert.ok(db)
+
+  assert.deepEqual(db.prepare('SELECT schema_version FROM meta').get(), { schema_version: CURRENT_SCHEMA_VERSION })
+  assert.deepEqual(db.prepare('SELECT summary, summary_message_count FROM segment').get(), {
+    summary: 'legacy summary',
+    summary_message_count: null,
+  })
+
+  manager.closeAll()
+})
+
 test('open migrates v7 databases to include analysis tool indexes', () => {
   const root = makeTempDir()
   const dbDir = path.join(root, 'data', 'databases')
diff --git a/packages/node-runtime/src/migrations/chat-db-migrations.ts b/packages/node-runtime/src/migrations/chat-db-migrations.ts
index a3e800b2..fbf5b27f 100644
--- a/packages/node-runtime/src/migrations/chat-db-migrations.ts
+++ b/packages/node-runtime/src/migrations/chat-db-migrations.ts
@@ -54,6 +54,14 @@ export function getChatDbMigrations(): CoreMigration[] {
     return tableInfo.some((col) => col.name === columnName)
   }
 
+  const hasTable = (db: DatabaseAdapter, tableName: string): boolean => {
+    return Boolean(
+      db.prepare("SELECT 1 FROM sqlite_master WHERE type = 'table' AND name = ?").get(tableName) as
+        | Record<string, unknown>
+        | undefined
+    )
+  }
+
   const addColumnIfMissing = (db: DatabaseAdapter, tableName: string, columnName: string, definition: string): void => {
     if (!hasColumn(db, tableName, columnName)) {
       db.exec(`ALTER TABLE ${tableName} ADD COLUMN ${columnName} ${definition}`)
@@ -372,5 +380,14 @@ export function getChatDbMigrations(): CoreMigration[] {
         db.exec('DROP TABLE IF EXISTS message_fts')
       },
     },
+    {
+      version: 10,
+      description: 'Track message coverage for generated segment summaries',
+      up: (db: DatabaseAdapter) => {
+        // Existing summaries may have been truncated or preserved after incremental imports.
+        // Keep their text for users to review, but leave coverage unknown so the new runtime marks them stale.
+        if (hasTable(db, 'segment')) addColumnIfMissing(db, 'segment', 'summary_message_count', 'INTEGER')
+      },
+    },
   ]
 }
diff --git a/packages/node-runtime/src/services/summary-service.ts b/packages/node-runtime/src/services/summary-service.ts
index 38abea9e..0fed1cc7 100644
--- a/packages/node-runtime/src/services/summary-service.ts
+++ b/packages/node-runtime/src/services/summary-service.ts
@@ -5,7 +5,7 @@
  * and summary generation loop — shared across CLI Web and Electron.
  */
 
-import { getSegmentSummary, saveSegmentSummary, getChatSessionList, getSegmentMessages } from '@openchatlab/core'
+import { getSegmentSummary, saveSegmentSummary, getChatSessionList, loadSegmentMessages } from '@openchatlab/core'
 import type { DatabaseAdapter } from '@openchatlab/core'
 import {
   generateSessionSummary,
@@ -29,10 +29,8 @@ export interface SummaryServiceDeps {
 function buildSummaryDeps(db: DatabaseAdapter, llmConfig: LlmConfig, deps: SummaryServiceDeps): SummaryDeps {
   const piModel = deps.buildPiModel(llmConfig)
   return {
-    loadMessages(segmentId, limit = 500) {
-      const data = getSegmentMessages(db, segmentId, limit)
-      if (!data) return null
-      return data.messages.map((m) => ({ senderName: m.senderName, content: m.content }))
+    loadMessages(segmentId, limit) {
+      return loadSegmentMessages(db, segmentId, limit)
     },
     saveSummary(segmentId, summary) {
       saveSegmentSummary(db, segmentId, summary)
@@ -109,10 +107,8 @@ export function checkCanGenerate(
 ): Record<number, { canGenerate: boolean; reason?: string }> {
   const db = adapter.ensureReadonly(sessionId)
   const deps: Pick<SummaryDeps, 'loadMessages' | 't'> = {
-    loadMessages(segmentId, limit = 500) {
-      const data = getSegmentMessages(db, segmentId, limit)
-      if (!data) return null
-      return data.messages.map((m) => ({ senderName: m.senderName, content: m.content }))
+    loadMessages(segmentId, limit) {
+      return loadSegmentMessages(db, segmentId, limit)
     },
     t: (key: string) => key,
   }
diff --git a/src/components/common/ChatRecord/BatchSummaryModal.vue b/src/components/common/ChatRecord/BatchSummaryModal.vue
index 7defed1e..a19e1910 100644
--- a/src/components/common/ChatRecord/BatchSummaryModal.vue
+++ b/src/components/common/ChatRecord/BatchSummaryModal.vue
@@ -47,6 +47,7 @@ interface SessionItem {
   messageCount: number
   // 与 sessionApi 返回值保持一致，历史数据里 summary 可能不存在。
   summary?: string | null
+  summaryMessageCount?: number | null
 }
 const sessions = ref<SessionItem[]>([])
 const isLoading = ref(false)
@@ -122,10 +123,18 @@ const timeRange = computed(() => {
 const canGenerateMap = ref<Record<number, { canGenerate: boolean; reason?: string }>>({})
 const isChecking = ref(false)
 
+function isSummaryStale(session: SessionItem): boolean {
+  return Boolean(session.summary) && session.summaryMessageCount !== session.messageCount
+}
+
+function hasFreshSummary(session: SessionItem): boolean {
+  return Boolean(session.summary) && !isSummaryStale(session)
+}
+
 // 待生成的会话（排除已有摘要的 + 消息太少的）
 const pendingSessions = computed(() => {
   return sessions.value.filter((s) => {
-    if (s.summary) return false
+    if (hasFreshSummary(s)) return false
     const checkResult = canGenerateMap.value[s.id]
     return checkResult?.canGenerate !== false
   })
@@ -133,13 +142,17 @@ const pendingSessions = computed(() => {
 
 // 已有摘要的会话数
 const existingSummaryCount = computed(() => {
-  return sessions.value.filter((s) => s.summary).length
+  return sessions.value.filter(hasFreshSummary).length
+})
+
+const staleSummaryCount = computed(() => {
+  return sessions.value.filter(isSummaryStale).length
 })
 
 // 消息数量太少的会话数（无摘要但无法生成）
 const tooFewMessagesCount = computed(() => {
   return sessions.value.filter((s) => {
-    if (s.summary) return false
+    if (hasFreshSummary(s)) return false
     const checkResult = canGenerateMap.value[s.id]
     return checkResult?.canGenerate === false
   }).length
@@ -199,7 +212,7 @@ async function fetchSessions() {
 
 // 批量检查会话是否可以生成摘要
 async function checkCanGenerate() {
-  const noSummaryIds = sessions.value.filter((s) => !s.summary).map((s) => s.id)
+  const noSummaryIds = sessions.value.filter((s) => !hasFreshSummary(s)).map((s) => s.id)
   if (noSummaryIds.length === 0) return
 
   isChecking.value = true
@@ -291,6 +304,7 @@ async function startGenerate() {
           const idx = sessions.value.findIndex((s) => s.id === session.id)
           if (idx !== -1) {
             sessions.value[idx].summary = result.summary || ''
+            sessions.value[idx].summaryMessageCount = sessions.value[idx].messageCount
           }
         } else if (result.error && isTooFewMessagesError(result.error)) {
           // 消息数量太少：标记为跳过
@@ -441,7 +455,7 @@ function close() {
               <p>
                 {{ t('records.batchSummary.found', '找到') }} {{ sessions.length }}
                 {{ t('records.batchSummary.sessionsUnit', '个会话') }}
-                <template v-if="existingSummaryCount > 0 || tooFewMessagesCount > 0">
+                <template v-if="existingSummaryCount > 0 || staleSummaryCount > 0 || tooFewMessagesCount > 0">
                   <span class="text-gray-500">
                     （
                     <template v-if="existingSummaryCount > 0">
@@ -449,7 +463,15 @@ function close() {
                         {{ existingSummaryCount }} {{ t('records.batchSummary.hasSummary', '个已有摘要') }}
                       </span>
                     </template>
-                    <template v-if="existingSummaryCount > 0 && tooFewMessagesCount > 0">，</template>
+                    <template v-if="existingSummaryCount > 0 && (staleSummaryCount > 0 || tooFewMessagesCount > 0)">
+                      ，
+                    </template>
+                    <template v-if="staleSummaryCount > 0">
+                      <span class="text-amber-600 dark:text-amber-400">
+                        {{ staleSummaryCount }} {{ t('records.batchSummary.needsUpdate', '个待更新') }}
+                      </span>
+                    </template>
+                    <template v-if="staleSummaryCount > 0 && tooFewMessagesCount > 0">，</template>
                     <template v-if="tooFewMessagesCount > 0">
                       <span class="text-gray-400">
                         {{ tooFewMessagesCount }} {{ t('records.batchSummary.tooFewMessages', '个消息太少') }}
diff --git a/src/components/common/ChatRecord/SessionTimeline.vue b/src/components/common/ChatRecord/SessionTimeline.vue
index 3308f327..987bc127 100644
--- a/src/components/common/ChatRecord/SessionTimeline.vue
+++ b/src/components/common/ChatRecord/SessionTimeline.vue
@@ -190,6 +190,10 @@ function formatTime(ts: number): string {
   return date.toLocaleTimeString(locale.value, { hour: '2-digit', minute: '2-digit' })
 }
 
+function isSummaryStale(session: ChatSessionItem): boolean {
+  return Boolean(session.summary) && session.summaryMessageCount !== session.messageCount
+}
+
 // 获取日期键
 function getDateKey(ts: number): string {
   const date = new Date(ts * 1000)
@@ -264,7 +268,11 @@ async function generateSummary(session: ChatSessionItem, event: Event) {
     if (result.success && result.summary) {
       const index = allSessions.value.findIndex((s) => s.id === session.id)
       if (index !== -1) {
-        const updatedSession = { ...allSessions.value[index], summary: result.summary }
+        const updatedSession = {
+          ...allSessions.value[index],
+          summary: result.summary,
+          summaryMessageCount: allSessions.value[index].messageCount,
+        }
         allSessions.value[index] = updatedSession
         emit('summary-updated', updatedSession)
       }
@@ -432,6 +440,12 @@ watch(
                         <span class="ml-1">
                           {{ (flatList[virtualItem.index] as { session: ChatSessionItem }).session.summary }}
                         </span>
+                        <span
+                          v-if="isSummaryStale((flatList[virtualItem.index] as { session: ChatSessionItem }).session)"
+                          class="ml-1 font-medium text-amber-500 dark:text-amber-400"
+                        >
+                          {{ t('records.timeline.summaryStale') }}
+                        </span>
                       </span>
                       <template #content>
                         <div class="max-w-sm whitespace-pre-wrap text-sm leading-relaxed font-normal">
@@ -445,7 +459,10 @@ watch(
                   </div>
 
                   <div
-                    v-if="!(flatList[virtualItem.index] as { session: ChatSessionItem }).session.summary"
+                    v-if="
+                      !(flatList[virtualItem.index] as { session: ChatSessionItem }).session.summary ||
+                      isSummaryStale((flatList[virtualItem.index] as { session: ChatSessionItem }).session)
+                    "
                     class="mt-0.5 flex min-w-0 items-center"
                   >
                     <!-- 无摘要且消息数>=3：显示生成按钮 -->
@@ -462,7 +479,13 @@ watch(
                         class="h-3 w-3 shrink-0 animate-spin"
                       />
                       <UIcon v-else name="i-heroicons-sparkles" class="h-3 w-3 shrink-0" />
-                      <span class="truncate">{{ t('records.timeline.generateSummary') }}</span>
+                      <span class="truncate">
+                        {{
+                          isSummaryStale((flatList[virtualItem.index] as { session: ChatSessionItem }).session)
+                            ? t('records.timeline.updateSummary')
+                            : t('records.timeline.generateSummary')
+                        }}
+                      </span>
                     </span>
 
                     <!-- 消息数<3：显示提示 -->
diff --git a/src/i18n/locales/en-US/records.json b/src/i18n/locales/en-US/records.json
index 3d779114..0a0efd1d 100644
--- a/src/i18n/locales/en-US/records.json
+++ b/src/i18n/locales/en-US/records.json
@@ -32,6 +32,8 @@
     "timeline": "Summaries",
     "noSessions": "No summaries",
     "generateSummary": "Summarize",
+    "updateSummary": "Update summary",
+    "summaryStale": "· Update needed",
     "tooFewMessages": "Too few"
   },
   "summaryFailed": "Summary generation failed",
@@ -54,6 +56,7 @@
     "custom": "Custom",
     "found": "Found",
     "hasSummary": "already summarized",
+    "needsUpdate": "need updates",
     "tooFewMessages": "too few messages",
     "pending": "Pending:",
     "unit": "",
diff --git a/src/i18n/locales/ja-JP/records.json b/src/i18n/locales/ja-JP/records.json
index 3628edd2..dcab2331 100644
--- a/src/i18n/locales/ja-JP/records.json
+++ b/src/i18n/locales/ja-JP/records.json
@@ -32,6 +32,8 @@
     "timeline": "要約",
     "noSessions": "要約がありません",
     "generateSummary": "要約を作成",
+    "updateSummary": "要約を更新",
+    "summaryStale": "· 更新が必要",
     "tooFewMessages": "メッセージが少なすぎます"
   },
   "summaryFailed": "要約の生成に失敗しました",
@@ -54,6 +56,7 @@
     "custom": "カスタム",
     "found": "見つかった",
     "hasSummary": "件は要約済み",
+    "needsUpdate": "件は更新が必要",
     "tooFewMessages": "件はメッセージ不足",
     "pending": "未生成:",
     "unit": "件",
diff --git a/src/i18n/locales/zh-CN/records.json b/src/i18n/locales/zh-CN/records.json
index 2aab08ea..b29084ab 100644
--- a/src/i18n/locales/zh-CN/records.json
+++ b/src/i18n/locales/zh-CN/records.json
@@ -32,6 +32,8 @@
     "timeline": "摘要",
     "noSessions": "暂无摘要",
     "generateSummary": "生成摘要",
+    "updateSummary": "更新摘要",
+    "summaryStale": "· 待更新",
     "tooFewMessages": "消息太少"
   },
   "summaryFailed": "摘要生成失败",
@@ -54,6 +56,7 @@
     "custom": "自定义",
     "found": "找到",
     "hasSummary": "个已有摘要",
+    "needsUpdate": "个待更新",
     "tooFewMessages": "个消息太少",
     "pending": "待生成:",
     "unit": "个",
diff --git a/src/i18n/locales/zh-TW/records.json b/src/i18n/locales/zh-TW/records.json
index a87cb18d..3b7ad60b 100644
--- a/src/i18n/locales/zh-TW/records.json
+++ b/src/i18n/locales/zh-TW/records.json
@@ -32,6 +32,8 @@
     "timeline": "摘要",
     "noSessions": "暫無摘要",
     "generateSummary": "產生摘要",
+    "updateSummary": "更新摘要",
+    "summaryStale": "· 待更新",
     "tooFewMessages": "訊息太少"
   },
   "summaryFailed": "摘要產生失敗",
@@ -54,6 +56,7 @@
     "custom": "自訂",
     "found": "找到",
     "hasSummary": "個已有摘要",
+    "needsUpdate": "個待更新",
     "tooFewMessages": "個訊息太少",
     "pending": "待產生:",
     "unit": "個",
diff --git a/src/services/session-index/fetch.ts b/src/services/session-index/fetch.ts
index 7648acbf..ad090131 100644
--- a/src/services/session-index/fetch.ts
+++ b/src/services/session-index/fetch.ts
@@ -88,7 +88,8 @@ export class FetchSessionIndexAdapter implements SessionIndexAdapter {
   async getSessions(sessionId: string): Promise<ChatSessionItem[]> {
     return getDataAdapter().pluginQuery<ChatSessionItem>(
       sessionId,
-      `SELECT id, start_ts as startTs, end_ts as endTs, message_count as messageCount, summary, ${FIRST_MESSAGE_ID_SUBQUERY}
+      `SELECT id, start_ts as startTs, end_ts as endTs, message_count as messageCount, summary,
+              summary_message_count as summaryMessageCount, ${FIRST_MESSAGE_ID_SUBQUERY}
        FROM segment ORDER BY start_ts ASC`,
       []
     )
@@ -97,7 +98,8 @@ export class FetchSessionIndexAdapter implements SessionIndexAdapter {
   async getByTimeRange(sessionId: string, startTs: number, endTs: number): Promise<ChatSessionItem[]> {
     return getDataAdapter().pluginQuery<ChatSessionItem>(
       sessionId,
-      `SELECT id, start_ts as startTs, end_ts as endTs, message_count as messageCount, summary, ${FIRST_MESSAGE_ID_SUBQUERY}
+      `SELECT id, start_ts as startTs, end_ts as endTs, message_count as messageCount, summary,
+              summary_message_count as summaryMessageCount, ${FIRST_MESSAGE_ID_SUBQUERY}
        FROM segment WHERE start_ts >= ? AND end_ts <= ? ORDER BY start_ts ASC`,
       [startTs, endTs]
     )
@@ -106,7 +108,8 @@ export class FetchSessionIndexAdapter implements SessionIndexAdapter {
   async getRecent(sessionId: string, limit: number): Promise<ChatSessionItem[]> {
     return getDataAdapter().pluginQuery<ChatSessionItem>(
       sessionId,
-      `SELECT id, start_ts as startTs, end_ts as endTs, message_count as messageCount, summary, ${FIRST_MESSAGE_ID_SUBQUERY}
+      `SELECT id, start_ts as startTs, end_ts as endTs, message_count as messageCount, summary,
+              summary_message_count as summaryMessageCount, ${FIRST_MESSAGE_ID_SUBQUERY}
        FROM segment ORDER BY start_ts DESC LIMIT ?`,
       [limit]
     )
diff --git a/src/services/session-index/types.ts b/src/services/session-index/types.ts
index 7d4efba6..9b7fdea9 100644
--- a/src/services/session-index/types.ts
+++ b/src/services/session-index/types.ts
@@ -18,6 +18,7 @@ export interface ChatSessionItem {
   messageCount: number
   firstMessageId: number
   summary?: string | null
+  summaryMessageCount?: number | null
 }
 
 export interface SummaryResult {