DevXDojo · WCY-dt · Aug 27, 2026 · Aug 25, 2026
diff --git a/frontend/cypress/e2e/article-operations.cy.ts b/frontend/cypress/e2e/article-operations.cy.ts
@@ -309,4 +309,154 @@ describe('Article Operations', () => {
     cy.wait('@searchArticleContent');
     cy.contains('Body for search result 102').should('be.visible');
   });
+
+  it('should preserve AI chat history across new conversations and request failures', () => {
+    const settingsState: Record<string, string> = {
+      language: 'en-US',
+      theme: 'light',
+      layout_mode: 'normal',
+      default_view_mode: 'rendered',
+      ai_chat_enabled: 'true',
+      translation_enabled: 'false',
+      summary_enabled: 'false',
+      full_text_fetch_enabled: 'false',
+      update_check_enabled: 'false',
+    };
+    const feed = {
+      id: 1,
+      title: 'Chat Feed',
+      url: 'https://example.com/chat.xml',
+      category: '',
+      article_view_mode: 'global',
+    };
+    const article = {
+      id: 1,
+      feed_id: 1,
+      feed_title: feed.title,
+      title: 'Chat article',
+      url: 'https://example.com/chat/article',
+      published_at: '2026-08-25T00:00:00Z',
+      is_read: false,
+      is_favorite: false,
+      is_hidden: false,
+      is_read_later: false,
+    };
+    let nextSessionID = 1;
+    const sessions: Array<Record<string, unknown>> = [];
+    const messages = new Map<number, Array<Record<string, unknown>>>();
+    const timestamp = () => new Date().toISOString();
+
+    cy.intercept('/api/**', { statusCode: 200, body: {} });
+    cy.intercept('GET', '/api/settings', { statusCode: 200, body: settingsState });
+    cy.intercept('GET', '/api/feeds', { statusCode: 200, body: [feed] }).as('chatFeeds');
+    cy.intercept('GET', '/api/tags', { statusCode: 200, body: [] });
+    cy.intercept('GET', '/api/saved-filters', { statusCode: 200, body: [] });
+    cy.intercept(
+      { method: 'GET', pathname: '/api/articles' },
+      { statusCode: 200, body: [article] }
+    ).as('chatArticles');
+    cy.intercept('GET', '/api/articles/unread-counts', { statusCode: 200, body: {} });
+    cy.intercept('GET', '/api/articles/filter-counts', { statusCode: 200, body: {} });
+    cy.intercept('GET', '/api/progress', {
+      statusCode: 200,
+      body: { is_running: true, pool_task_count: 0, queue_task_count: 0 },
+    });
+    cy.intercept('GET', '/api/articles/content*', {
+      statusCode: 200,
+      body: { content: '<p>Article context for AI chat</p>', cached: true },
+    }).as('chatArticleContent');
+    cy.intercept('POST', '/api/articles/read*', { statusCode: 200, body: { success: true } });
+    cy.intercept('GET', '/api/ai/chat/sessions*', (req) => {
+      req.reply({ statusCode: 200, body: sessions });
+    }).as('chatSessions');
+    cy.intercept('GET', '/api/ai/chat/messages*', (req) => {
+      req.reply({ statusCode: 200, body: messages.get(Number(req.query.session_id)) || [] });
+    }).as('chatMessages');
+    cy.intercept('POST', '/api/ai/chat/session/create', (req) => {
+      const id = nextSessionID++;
+      const session = {
+        id,
+        article_id: 1,
+        title: req.body.title,
+        created_at: timestamp(),
+        updated_at: timestamp(),
+        message_count: 0,
+      };
+      sessions.unshift(session);
+      messages.set(id, []);
+      req.reply({ statusCode: 200, body: session });
+    }).as('createChatSession');
+    cy.intercept('POST', '/api/ai-chat', (req) => {
+      const lastMessage = req.body.messages.at(-1)?.content || '';
+      let sessionID = Number(req.body.session_id || 0);
+      if (!sessionID) {
+        sessionID = nextSessionID++;
+        sessions.unshift({
+          id: sessionID,
+          article_id: 1,
+          title: lastMessage.slice(0, 60),
+          created_at: timestamp(),
+          updated_at: timestamp(),
+          message_count: 0,
+        });
+      }
+      const stored = messages.get(sessionID) || [];
+      stored.push({
+        id: stored.length + 1,
+        role: 'user',
+        content: lastMessage,
+        created_at: timestamp(),
+      });
+      messages.set(sessionID, stored);
+
+      if (lastMessage === 'trigger failure') {
+        req.reply({
+          statusCode: 500,
+          body: { error: 'Failed to get response from AI. Please try again.', session_id: sessionID },
+        });
+        return;
+      }
+
+      stored.push({
+        id: stored.length + 1,
+        role: 'assistant',
+        content: 'Persisted answer',
+        created_at: timestamp(),
+      });
+      const session = sessions.find((item) => item.id === sessionID);
+      if (session) session.message_count = stored.length;
+      req.reply({
+        statusCode: 200,
+        body: { response: 'Persisted answer', session_id: sessionID, history_saved: true },
+      });
+    }).as('aiChat');
+
+    cy.reload();
+    cy.wait('@chatFeeds');
+    cy.wait('@chatArticles');
+    cy.get('[data-article-id="1"]').click();
+    cy.wait('@chatArticleContent');
+    cy.get('button[title="AI Chat"]').click();
+    cy.wait('@chatSessions');
+
+    cy.get('input[placeholder="Type a message..."]').type('First question{enter}');
+    cy.wait('@aiChat');
+    cy.contains('.chat-panel', 'Persisted answer').should('be.visible');
+
+    cy.get('[data-testid="chat-new-session"]').click();
+    cy.wait('@createChatSession');
+    cy.wait('@chatMessages');
+    cy.contains('.chat-panel', 'Persisted answer').should('not.exist');
+    cy.get('[data-testid="chat-session-switcher"]').click();
+    cy.get('.chat-panel [data-session-id="1"]').click();
+    cy.wait('@chatMessages');
+    cy.contains('.chat-panel', 'Persisted answer').should('be.visible');
+
+    cy.get('input[placeholder="Type a message..."]').type('trigger failure{enter}');
+    cy.wait('@aiChat');
+    cy.wait('@chatMessages');
+    cy.contains('.chat-panel', 'trigger failure').should('be.visible');
+    cy.contains('Failed to get response from AI. Please try again.').should('be.visible');
+  });
+
 });
diff --git a/frontend/src/components/article/ArticleChatPanel.vue b/frontend/src/components/article/ArticleChatPanel.vue
@@ -86,7 +86,8 @@ async function loadSessions() {
   }
 }
 
-async function selectSession(sessionId: number) {
+async function selectSession(sessionId: number, force = false) {
+  if (isLoading.value && !force) return;
   try {
     const response = await fetch(`/api/ai/chat/messages?session_id=${sessionId}`);
     if (response.ok) {
@@ -106,6 +107,7 @@ async function selectSession(sessionId: number) {
 }
 
 async function createNewSession() {
+  if (isLoading.value) return;
   try {
     const response = await fetch('/api/ai/chat/session/create', {
       method: 'POST',
@@ -131,6 +133,7 @@ async function createNewSession() {
 
 async function deleteSession(sessionId: number, e: Event) {
   e.stopPropagation();
+  if (isLoading.value) return;
   const confirmed = await window.showConfirm({
     title: t('common.confirm'),
     message: t('article.chat.confirmDeleteSession'),
@@ -158,6 +161,7 @@ async function deleteSession(sessionId: number, e: Event) {
 
 function startEditSession(session: ChatSession, e: Event) {
   e.stopPropagation();
+  if (isLoading.value) return;
   editingSessionId.value = session.id;
   editingSessionTitle.value = session.title;
 }
@@ -277,19 +281,25 @@ async function sendMessage() {
         created_at: new Date().toISOString(),
       });
 
-      if (data.session_id && data.session_id !== currentSessionId.value) {
+      if (data.session_id) {
         currentSessionId.value = data.session_id;
         await loadSessions();
       }
 
+      if (data.history_saved === false) {
+        window.showToast(t('article.chat.historySaveFailed'), 'warning');
+      }
+
       isFirstMessage.value = false;
     } else {
       const errorText = await response.text();
-      console.error('AI chat error response:', response.status, errorText);
+      console.error('AI chat request failed:', response.status);
 
       let errorMessage = t('article.chat.aiChatError');
+      let persistedSessionID = 0;
       try {
         const errorData = JSON.parse(errorText);
+        persistedSessionID = Number(errorData.session_id || 0);
         // Extract error message from various possible formats
         if (typeof errorData.error === 'string') {
           errorMessage = errorData.error;
@@ -303,24 +313,19 @@ async function sendMessage() {
           errorMessage = t('article.chat.aiChatError');
         }
       } catch {
-        errorMessage = errorText || t('article.chat.aiChatError');
+        errorMessage = t('article.chat.aiChatError');
       }
 
-      messages.value.push({
-        id: 0,
-        role: 'assistant',
-        content: errorMessage,
-        created_at: new Date().toISOString(),
-      });
+      if (persistedSessionID > 0) {
+        currentSessionId.value = persistedSessionID;
+        await loadSessions();
+        await selectSession(persistedSessionID, true);
+      }
+      window.showToast(errorMessage, 'error');
     }
   } catch (e) {
     console.error('AI chat error:', e);
-    messages.value.push({
-      id: 0,
-      role: 'assistant',
-      content: t('article.chat.aiChatError'),
-      created_at: new Date().toISOString(),
-    });
+    window.showToast(t('article.chat.aiChatError'), 'error');
   } finally {
     isLoading.value = false;
     await nextTick();
@@ -367,8 +372,10 @@ const currentSessionTitle = computed(() => {
             <PhChatCircleText :size="20" class="text-accent" />
             <button
               class="flex items-center gap-1 text-sm font-medium hover:text-accent transition-colors"
+              :disabled="isLoading"
               :title="t('article.chat.switchSession')"
-              @click="showSessions = !showSessions"
+              data-testid="chat-session-switcher"
+              @click.stop="showSessions = !showSessions"
             >
               <span>{{ currentSessionTitle }}</span>
               <PhClockCounterClockwise :size="16" />
@@ -377,8 +384,10 @@ const currentSessionTitle = computed(() => {
           <div class="flex items-center gap-1">
             <button
               class="p-1 hover:bg-bg-tertiary rounded-lg transition-colors"
+              :disabled="isLoading"
               :title="t('article.chat.newChat')"
-              @click="createNewSession"
+              data-testid="chat-new-session"
+              @click.stop="createNewSession"
             >
               <PhPlus :size="18" class="text-text-secondary" />
             </button>
@@ -412,8 +421,12 @@ const currentSessionTitle = computed(() => {
                 v-for="session in sessions"
                 :key="session.id"
                 class="flex items-center gap-2 p-2 rounded-lg hover:bg-bg-tertiary cursor-pointer group"
-                :class="{ 'bg-bg-tertiary': session.id === currentSessionId }"
-                @click="selectSession(session.id)"
+                :class="{
+                  'bg-bg-tertiary': session.id === currentSessionId,
+                  'pointer-events-none opacity-60': isLoading,
+                }"
+                :data-session-id="session.id"
+                @click.stop="selectSession(session.id)"
               >
                 <PhChatCircleText :size="16" class="text-text-secondary" />
                 <div v-if="editingSessionId === session.id" class="flex-1 flex items-center gap-1">
@@ -490,9 +503,9 @@ const currentSessionTitle = computed(() => {
               </div>
               <!-- Message content with pre-rendered HTML from backend -->
               <div
-                v-if="msg.role === 'assistant'"
+                v-if="msg.role === 'assistant' && msg.html"
                 class="prose prose-sm max-w-none"
-                v-html="msg.html || msg.content"
+                v-html="msg.html"
               ></div>
               <div v-else class="whitespace-pre-wrap break-words">{{ msg.content }}</div>
             </div>

diff --git a/frontend/src/i18n/locales/en.ts b/frontend/src/i18n/locales/en.ts
@@ -64,6 +64,7 @@ const en: TranslationMessages = {
     chat: {
       aiChat: 'AI Chat',
       aiChatError: 'Failed to get response from AI. Please try again.',
+      historySaveFailed: 'The answer was generated but could not be saved to chat history.',
       aiChatInputPlaceholder: 'Type a message...',
       aiChatWelcome: 'Ask me anything about this article!',
       confirmDeleteSession: 'Are you sure you want to delete this chat session?',

diff --git a/frontend/src/i18n/locales/zh.ts b/frontend/src/i18n/locales/zh.ts
@@ -61,6 +61,7 @@ const zh: TranslationMessages = {
     chat: {
       aiChat: 'AI 聊天',
       aiChatError: '无法获取 AI 响应，请重试。',
+      historySaveFailed: '回答已生成，但未能保存到历史记录。',
       aiChatInputPlaceholder: '输入消息...',
       aiChatWelcome: '请问关于这篇文章的任何问题！',
       confirmDeleteSession: '确定要删除这个对话吗？',

diff --git a/internal/database/article_db_test.go b/internal/database/article_db_test.go
@@ -605,6 +605,39 @@ func TestSaveArticlesUpdatePreservesRelatedData(t *testing.T) {
 	if session == nil || session.MessageCount != 1 {
 		t.Fatalf("chat data was not preserved: session=%+v", session)
 	}
+
+	newerSessionID, err := db.CreateChatSession(articleID, "New conversation")
+	if err != nil {
+		t.Fatalf("CreateChatSession(newer) error: %v", err)
+	}
+	if _, err := db.Exec(
+		`UPDATE chat_sessions SET updated_at = '2026-08-25 10:00:00' WHERE id IN (?, ?)`,
+		sessionID, newerSessionID,
+	); err != nil {
+		t.Fatalf("align chat session timestamps: %v", err)
+	}
+	firstMessageID, err := db.CreateChatMessage(newerSessionID, "user", "First in the same second", "")
+	if err != nil {
+		t.Fatalf("CreateChatMessage(first) error: %v", err)
+	}
+	secondMessageID, err := db.CreateChatMessage(newerSessionID, "assistant", "Second in the same second", "thinking")
+	if err != nil {
+		t.Fatalf("CreateChatMessage(second) error: %v", err)
+	}
+	if _, err := db.Exec(
+		`UPDATE chat_sessions SET updated_at = '2026-08-25 10:00:00' WHERE id IN (?, ?)`,
+		sessionID, newerSessionID,
+	); err != nil {
+		t.Fatalf("restore aligned chat session timestamps: %v", err)
+	}
+	sessions, err := db.GetChatSessionsByArticle(articleID)
+	if err != nil || len(sessions) != 2 || sessions[0].ID != newerSessionID {
+		t.Fatalf("chat session order = %+v, err=%v", sessions, err)
+	}
+	messages, err := db.GetChatMessages(newerSessionID)
+	if err != nil || len(messages) != 2 || messages[0].ID != firstMessageID || messages[1].ID != secondMessageID {
+		t.Fatalf("chat message order = %+v, err=%v", messages, err)
+	}
 }
 
 func TestArticleDeduplicationByUniqueID(t *testing.T) {

diff --git a/internal/database/chat_db.go b/internal/database/chat_db.go
@@ -67,7 +67,7 @@ func (db *DB) GetChatSessionsByArticle(articleID int64) ([]ChatSession, error) {
 		       (SELECT COUNT(*) FROM chat_messages WHERE session_id = chat_sessions.id) as message_count
 		FROM chat_sessions
 		WHERE article_id = ?
-		ORDER BY updated_at DESC
+		ORDER BY updated_at DESC, id DESC
 	`, articleID)
 	if err != nil {
 		return nil, fmt.Errorf("failed to get chat sessions: %w", err)
@@ -149,7 +149,7 @@ func (db *DB) GetChatMessages(sessionID int64) ([]ChatMessage, error) {
 		SELECT id, session_id, role, content, thinking, created_at
 		FROM chat_messages
 		WHERE session_id = ?
-		ORDER BY created_at ASC
+		ORDER BY created_at ASC, id ASC
 	`, sessionID)
 	if err != nil {
 		return nil, fmt.Errorf("failed to get chat messages: %w", err)