diff --git a/backend/src/views/apps/ai/components/chatWindow.vue b/backend/src/views/apps/ai/components/chatWindow.vue
index c00f12b..dbf6cc9 100644
--- a/backend/src/views/apps/ai/components/chatWindow.vue
+++ b/backend/src/views/apps/ai/components/chatWindow.vue
@@ -17,7 +17,6 @@
         <el-select
           v-model="selectedProviderId"
           placeholder="选择接入"
-          size="small"
           class="provider-select"
           @change="handleProviderChange"
         >
@@ -31,7 +30,6 @@
         <el-select
           v-model="selectedModel"
           placeholder="选择模型"
-          size="small"
           class="model-select"
           :disabled="!selectedProviderId"
         >
@@ -124,6 +122,9 @@
               <div v-if="msg.role === 'assistant' && sending" class="generating-indicator">
                 <el-icon class="is-loading"><Loading /></el-icon>
               </div>
+              <div v-if="msg.images && msg.images.length" class="message-images">
+                <img v-for="(img, i) in msg.images" :key="i" :src="img" class="message-image" alt="图片" />
+              </div>
               <template v-if="msg.role === 'assistant' && !msg.content && sending">
                 <span class="thinking-text">思考中…</span>
               </template>
@@ -157,9 +158,11 @@
               </template>
             </div>
             <div
-              v-if="msg.role === 'assistant' && (msg.tokens || msg.durationMs)"
+              v-if="msg.role === 'assistant' && (msg.tokens || msg.durationMs || msg.firstTokenMs)"
               class="message-meta"
             >
+              <span v-if="msg.firstTokenMs" class="meta-item">首字 {{ (msg.firstTokenMs / 1000).toFixed(1) }}s</span>
+              <span v-if="msg.firstTokenMs" class="meta-dot">·</span>
               <span class="meta-item">{{ formatDuration(msg.durationMs) }}</span>
               <span class="meta-dot">·</span>
               <span class="meta-item">{{ msg.tokens }} tokens</span>
@@ -186,26 +189,47 @@
     </div>
 
     <div class="chat-input-area">
+      <div v-if="lastAssistant && lastAssistant.firstTokenMs" class="input-status">
+        <span>首字 {{ (lastAssistant.firstTokenMs / 1000).toFixed(1) }}s</span>
+        <template v-if="lastAssistant.durationMs">
+          <span class="meta-dot">·</span>
+          <span>共 {{ (lastAssistant.durationMs / 1000).toFixed(1) }}s</span>
+        </template>
+        <template v-if="lastAssistant.tokens">
+          <span class="meta-dot">·</span>
+          <span>{{ lastAssistant.tokens }} tokens</span>
+        </template>
+      </div>
       <div class="input-wrapper">
-        <el-input
-          v-model="inputText"
-          type="textarea"
-          :rows="2"
-          :autosize="{ minRows: 2, maxRows: 6 }"
-          placeholder="输入消息，Enter发送，Shift+Enter换行"
-          @keydown.enter.exact.prevent="handleSend"
-          resize="none"
-        />
-        <el-button
-          type="primary"
-          class="send-btn"
-          :icon="Promotion"
-          :loading="sending"
-          :disabled="!inputText.trim()"
-          @click="handleSend"
-        >
-          发送
-        </el-button>
+        <div v-if="inputImages.length" class="input-images">
+          <div v-for="(img, i) in inputImages" :key="i" class="input-image-item">
+            <img :src="img" alt="待发送图片" />
+            <el-icon class="input-image-remove" @click="removeInputImage(i)"><Close /></el-icon>
+          </div>
+        </div>
+        <div class="input-row">
+          <el-input
+            v-model="inputText"
+            type="textarea"
+            :rows="3"
+            resize="vertical"
+            placeholder="输入消息，Enter发送，Shift+Enter换行；可粘贴图片"
+            @keydown.enter.exact.prevent="handleSend"
+            @paste="onInputPaste"
+          />
+          <div class="input-actions">
+            <el-button
+              type="primary"
+              class="send-btn"
+              :icon="Promotion"
+              :loading="sending"
+              :disabled="(!inputText.trim() && inputImages.length === 0) || sending"
+              @click="handleSend"
+            >
+              发送
+            </el-button>
+          </div>
+        </div>
       </div>
       <div class="input-tip">AI生成内容仅供参考，请核实重要信息</div>
     </div>
@@ -217,7 +241,7 @@
 <script setup>
 import { ref, nextTick, watch, computed, onMounted } from 'vue'
 import { ElMessage } from 'element-plus'
-import { User, Cpu, Promotion, Edit, CopyDocument, RefreshRight, Delete, UserFilled, Loading } from '@element-plus/icons-vue'
+import { User, Cpu, Promotion, Edit, CopyDocument, RefreshRight, Delete, UserFilled, Loading, Close } from '@element-plus/icons-vue'
 import { getChatMessageList, sendChatMessage, getAiProviderList, deleteChatMessage, getAiPresetList, getMcpServerList } from '@/api/ai'
 import PresetDialog from './presetDialog.vue'
 
@@ -231,6 +255,8 @@ const emit = defineEmits(['session-created'])
 const loading = ref(false)
 const sending = ref(false)
 const inputText = ref('')
+// 待发送的图片（base64 dataURL）
+const inputImages = ref([])
 const messages = ref([])
 const messagesRef = ref()
 // 流式回复进行中时 sessionId 变化的暂存值（等待本轮结束后再加载历史）
@@ -254,14 +280,21 @@ const defaultPreset = ref(null)
 
 // MCP 接入状态
 const activeMcpTools = ref([])
-// 本轮对话是否启用 MCP 工具（本地记忆上次选择）
+// 本轮对话是否启用 MCP 工具；默认开启，以 MCP 市场配置为准（市场已启用服务即可被调用）
 const savedMcp = loadMcpSetting()
-const mcpEnabled = ref(savedMcp.enabled)
+const mcpEnabled = ref(true)
 // 参与本轮对话的 MCP 服务器（默认全部已启用的服务）
 const selectedMcpServers = ref(savedMcp.serverIds)
 const mcpServerList = ref([])
 // 开关打开且至少勾选了一个服务才算真正启用
 const mcpOn = computed(() => mcpEnabled.value && selectedMcpServers.value.length > 0)
+// 最近一条助手消息（用于输入框上方状态栏展示首字耗时等）
+const lastAssistant = computed(() => {
+  for (let i = messages.value.length - 1; i >= 0; i--) {
+    if (messages.value[i].role === 'assistant') return messages.value[i]
+  }
+  return null
+})
 const mcpTip = computed(() => {
   if (!mcpEnabled.value) {
     return 'MCP 工具已关闭，本轮对话不会调用任何 MCP 工具'
@@ -276,10 +309,8 @@ const mcpTip = computed(() => {
 })
 
 function loadMcpSetting() {
-  const setting = { enabled: true, serverIds: [] }
+  const setting = { serverIds: [] }
   try {
-    const e = localStorage.getItem('ai_mcp_enabled')
-    if (e !== null) setting.enabled = e === '1'
     const s = localStorage.getItem('ai_mcp_servers')
     if (s) setting.serverIds = JSON.parse(s) || []
   } catch (e) {
@@ -290,13 +321,42 @@ function loadMcpSetting() {
 
 function persistMcpSetting() {
   try {
-    localStorage.setItem('ai_mcp_enabled', mcpEnabled.value ? '1' : '0')
     localStorage.setItem('ai_mcp_servers', JSON.stringify(selectedMcpServers.value))
   } catch (e) {
     // 忽略
   }
 }
 
+// 用户选择的接入/模型偏好（持久化，避免每次重新选择）
+function loadModelSetting() {
+  const s = { providerId: null, model: '' }
+  try {
+    const p = localStorage.getItem('ai_selected_provider')
+    const m = localStorage.getItem('ai_selected_model')
+    if (p) s.providerId = Number(p)
+    if (m) s.model = m
+  } catch (e) {
+    // 忽略
+  }
+  return s
+}
+
+function saveModelSetting(providerId, model) {
+  try {
+    localStorage.setItem('ai_selected_provider', String(providerId ?? ''))
+    localStorage.setItem('ai_selected_model', String(model ?? ''))
+  } catch (e) {
+    // 忽略
+  }
+}
+
+// 接入/模型变化时持久化用户选择
+watch([selectedProviderId, selectedModel], () => {
+  if (selectedProviderId.value && selectedModel.value) {
+    saveModelSetting(selectedProviderId.value, selectedModel.value)
+  }
+})
+
 // 将毫秒格式化为可读耗时
 function formatDuration(ms) {
   if (!ms || ms <= 0) return '0ms'
@@ -315,6 +375,8 @@ onMounted(() => {
   fetchMcpStatus()
 })
 
+// 是否已根据市场配置完成首次自动开启
+let mcpLoaded = false
 async function fetchMcpStatus() {
   try {
     const res = await getMcpServerList()
@@ -324,6 +386,11 @@ async function fetchMcpStatus() {
       // 过滤掉已删除/已停用的服务；没有历史选择时默认全选
       const valid = selectedMcpServers.value.filter((id) => mcpServerList.value.some((s) => s.id === id))
       selectedMcpServers.value = valid.length > 0 ? valid : mcpServerList.value.map((s) => s.id)
+      // 首次加载且市场存在已启用的服务时，自动开启 MCP（无需再手动打开开关）
+      if (!mcpLoaded && mcpServerList.value.length > 0) {
+        mcpEnabled.value = true
+      }
+      mcpLoaded = true
     }
   } catch (e) {
     // 静默失败
@@ -346,13 +413,22 @@ async function fetchProviders() {
     const res = await getAiProviderList()
     if (res.code === 200) {
       providerList.value = res.data.list || []
-      // 默认选第一个启用的
+      const saved = loadModelSetting()
+      // 优先使用已保存的接入/模型，否则默认选第一个启用的
       const firstActive = providerList.value.find(p => p.status === 1)
-      if (firstActive) {
+      if (saved.providerId && providerList.value.some(p => p.id === saved.providerId)) {
+        selectedProviderId.value = saved.providerId
+      } else if (firstActive) {
         selectedProviderId.value = firstActive.id
-        if (firstActive.models && firstActive.models.length > 0) {
-          selectedModel.value = firstActive.models[0]
-        }
+      }
+      const provider = providerList.value.find(p => p.id === selectedProviderId.value)
+      const models = provider && provider.models ? provider.models : []
+      if (saved.model && models.includes(saved.model)) {
+        selectedModel.value = saved.model
+      } else if (models.length > 0) {
+        selectedModel.value = models[0]
+      } else {
+        selectedModel.value = ''
       }
     }
   } catch (e) {
@@ -411,9 +487,12 @@ async function fetchMessages(sessionId) {
 
 async function handleSend() {
   const content = inputText.value.trim()
-  if (!content || sending.value) return
+  const images = inputImages.value
+  if ((!content && images.length === 0) || sending.value) return
   inputText.value = ''
-  await doSend(content)
+  const imgs = images.slice()
+  inputImages.value = []
+  await doSend(content, imgs)
 }
 
 // ===== 消息操作 =====
@@ -529,9 +608,39 @@ async function deleteMessage(msg, idx) {
   }
 }
 
+// 选择图片并读取为 base64 dataURL
+function removeInputImage(i) {
+  inputImages.value.splice(i, 1)
+}
+
+// 在输入框中粘贴图片（Ctrl+V）
+function onInputPaste(e) {
+  const cd = e.clipboardData || window.clipboardData
+  if (!cd || !cd.items) return
+  const items = Array.from(cd.items)
+  const hasText = items.some(it => it.kind === 'string' && it.type === 'text/plain')
+  let added = false
+  for (const it of items) {
+    if (it.kind === 'file' && it.type && it.type.startsWith('image/')) {
+      const file = it.getAsFile()
+      if (!file) continue
+      if (file.size > 8 * 1024 * 1024) {
+        ElMessage.warning(`图片「${file.name || '剪贴板图片'}」超过 8MB，已跳过`)
+        continue
+      }
+      const reader = new FileReader()
+      reader.onload = () => { inputImages.value.push(reader.result) }
+      reader.readAsDataURL(file)
+      added = true
+    }
+  }
+  // 剪贴板只含图片时阻止默认行为，避免把文件名等当作文本插入
+  if (added && !hasText) e.preventDefault()
+}
+
 // 内部发送方法（供编辑/重新发送调用）
-async function doSend(content) {
-  if (!content || sending.value) return
+async function doSend(content, images = []) {
+  if ((!content && (!images || images.length === 0)) || sending.value) return
   if (!selectedProviderId.value) {
     ElMessage.warning('请先选择接入')
     return
@@ -542,14 +651,16 @@ async function doSend(content) {
   }
 
   // 添加用户消息
-  messages.value.push({ role: 'user', content })
+  messages.value.push({ role: 'user', content, images: images ? images.slice() : [] })
   // 注意：必须取数组内的响应式代理对象来修改，直接持有 push 进去的原始对象不会触发视图更新
   const userMsg = messages.value[messages.value.length - 1]
   // 添加空的AI消息，用于流式更新
-  messages.value.push({ id: null, role: 'assistant', content: '', toolCalls: [], tokens: 0, durationMs: 0, model: '', error: false })
+  messages.value.push({ id: null, role: 'assistant', content: '', toolCalls: [], tokens: 0, durationMs: 0, model: '', error: false, firstTokenMs: 0 })
   const aiIndex = messages.value.length - 1
   const aiMsg = messages.value[aiIndex]
   sending.value = true
+  // 本轮开始时间，用于计算首字耗时（TTFT）
+  const startTimeMs = Date.now()
   scrollToBottom()
 
   try {
@@ -567,7 +678,8 @@ async function doSend(content) {
         provider_id: selectedProviderId.value,
         model: selectedModel.value,
         mcp_enabled: mcpOn.value,
-        mcp_server_ids: mcpOn.value ? selectedMcpServers.value : []
+        mcp_server_ids: mcpOn.value ? selectedMcpServers.value : [],
+        images: images
       })
     })
 
@@ -596,10 +708,13 @@ async function doSend(content) {
             selfSessionSwitch.value = true
             emit('session-created', {
               id: parsed.session_id,
-              title: content.length > 20 ? content.slice(0, 20) + '...' : content
+              title: (content || '[图片消息]').length > 20 ? (content || '[图片消息]').slice(0, 20) + '...' : (content || '[图片消息]')
             })
           }
         } else if (eventType === 'content') {
+          if (!aiMsg.content) {
+            aiMsg.firstTokenMs = Date.now() - startTimeMs
+          }
           aiMsg.content += parsed.content
           scrollToBottom()
         } else if (eventType === 'tool_list') {
@@ -762,10 +877,20 @@ defineExpose({
 
     .provider-select {
       width: 200px;
+      height: 32px;
+
+      :deep(.el-select__wrapper) {
+        height: 32px;
+      }
     }
 
     .model-select {
       width: 180px;
+      height: 32px;
+
+      :deep(.el-select__wrapper) {
+        height: 32px;
+      }
     }
   }
 }
@@ -979,12 +1104,13 @@ defineExpose({
 
   .input-wrapper {
     display: flex;
-    gap: 12px;
-    align-items: flex-end;
+    flex-direction: column;
+    gap: 8px;
 
-    .send-btn {
-      height: 40px;
-      flex-shrink: 0;
+    .input-row {
+      display: flex;
+      gap: 12px;
+      align-items: stretch;
     }
   }
 
@@ -994,6 +1120,83 @@ defineExpose({
     color: var(--el-text-color-placeholder);
     margin-top: 8px;
   }
+
+  // 输入框上方状态栏（首字耗时等）
+  .input-status {
+    display: flex;
+    align-items: center;
+    gap: 6px;
+    font-size: 12px;
+    color: var(--el-text-color-secondary);
+    padding: 0 2px 4px;
+
+    .meta-dot {
+      color: var(--el-border-color);
+    }
+  }
+
+  // 待发送图片预览
+  .input-images {
+    display: flex;
+    flex-wrap: wrap;
+    gap: 8px;
+    margin-bottom: 8px;
+  }
+
+  .input-image-item {
+    position: relative;
+    width: 64px;
+    height: 64px;
+    border-radius: 6px;
+    overflow: hidden;
+    border: 1px solid var(--el-border-color);
+
+    img {
+      width: 100%;
+      height: 100%;
+      object-fit: cover;
+    }
+
+    .input-image-remove {
+      position: absolute;
+      top: 2px;
+      right: 2px;
+      background: rgba(0, 0, 0, 0.55);
+      color: #fff;
+      border-radius: 50%;
+      cursor: pointer;
+      font-size: 12px;
+      padding: 2px;
+    }
+  }
+
+  // 输入框右侧操作区
+  .input-actions {
+    display: flex;
+    flex-direction: column;
+    flex-shrink: 0;
+
+    .send-btn {
+      flex: 1;
+      height: 100%;
+    }
+  }
+}
+
+// 消息内图片
+.message-images {
+  display: flex;
+  flex-wrap: wrap;
+  gap: 6px;
+  margin-bottom: 6px;
+}
+
+.message-image {
+  max-width: 220px;
+  max-height: 220px;
+  border-radius: 6px;
+  border: 1px solid var(--el-border-color-lighter);
+  object-fit: cover;
 }
 
 // MCP 状态指示
diff --git a/go/controllers/backend_ai_chat.go b/go/controllers/backend_ai_chat.go
index aa80e2b..f9c7002 100644
--- a/go/controllers/backend_ai_chat.go
+++ b/go/controllers/backend_ai_chat.go
@@ -63,6 +63,8 @@ type chatSendPayload struct {
 	McpEnabled *bool `json:"mcp_enabled"`
 	// McpServerIDs 限定参与本轮对话的 MCP 服务器；为空表示使用全部已启用的服务器
 	McpServerIDs []uint64 `json:"mcp_server_ids"`
+	// Images 用户上传的图片（base64 dataURL），仅多模态模型可用
+	Images []string `json:"images"`
 }
 
 // mcpEnabled 解析本轮是否启用 MCP（未传默认开启）
@@ -78,6 +80,49 @@ type openaiMessage struct {
 	Content    string           `json:"content,omitempty"`
 	ToolCalls  []openaiToolCall `json:"tool_calls,omitempty"`
 	ToolCallID string           `json:"tool_call_id,omitempty"`
+	// Images 仅 user 消息使用，存放 base64 dataURL，用于多模态输入
+	Images []string `json:"-"`
+}
+
+// openAIMessages 将内部消息转换为 OpenAI 兼容的请求结构。
+// 当且仅当 user 消息携带图片时，content 会被构造为多模态 parts（text + image_url）。
+func openAIMessages(messages []openaiMessage) []map[string]interface{} {
+	out := make([]map[string]interface{}, 0, len(messages))
+	for _, m := range messages {
+		item := map[string]interface{}{"role": m.Role}
+		if len(m.Images) > 0 {
+			parts := []map[string]interface{}{}
+			if strings.TrimSpace(m.Content) != "" {
+				parts = append(parts, map[string]interface{}{"type": "text", "text": m.Content})
+			}
+			for _, img := range m.Images {
+				parts = append(parts, map[string]interface{}{
+					"type":      "image_url",
+					"image_url": map[string]interface{}{"url": img},
+				})
+			}
+			item["content"] = parts
+		} else {
+			item["content"] = m.Content
+		}
+		if len(m.ToolCalls) > 0 {
+			item["tool_calls"] = m.ToolCalls
+		}
+		if m.ToolCallID != "" {
+			item["tool_call_id"] = m.ToolCallID
+		}
+		out = append(out, item)
+	}
+	return out
+}
+
+// marshalImages 将图片列表序列化为可存储的 JSON 字符串（无图片返回空串）
+func marshalImages(imgs []string) string {
+	if len(imgs) == 0 {
+		return ""
+	}
+	b, _ := json.Marshal(imgs)
+	return string(b)
 }
 
 type openaiToolCall struct {
@@ -522,7 +567,12 @@ func loadHistory(sessionID uint64) []openaiMessage {
 		All(&history)
 	out := make([]openaiMessage, 0, len(history)+1)
 	for i := len(history) - 1; i >= 0; i-- {
-		out = append(out, openaiMessage{Role: history[i].Role, Content: history[i].Content})
+		h := history[i]
+		imgs := []string{}
+		if strings.TrimSpace(h.Images) != "" {
+			_ = json.Unmarshal([]byte(h.Images), &imgs)
+		}
+		out = append(out, openaiMessage{Role: h.Role, Content: h.Content, Images: imgs})
 	}
 	return out
 }
@@ -547,7 +597,7 @@ func (c *BackendAiChatController) Send() {
 		c.chatJsonErr(400, 400, "参数格式错误")
 		return
 	}
-	if strings.TrimSpace(p.Content) == "" {
+	if strings.TrimSpace(p.Content) == "" && len(p.Images) == 0 {
 		c.chatJsonErr(400, 400, "消息内容不能为空")
 		return
 	}
@@ -570,7 +620,7 @@ func (c *BackendAiChatController) Send() {
 	systemPrompt := loadSystemPrompt(claims)
 
 	messages := loadHistory(session.ID)
-	messages = append(messages, openaiMessage{Role: "user", Content: p.Content})
+	messages = append(messages, openaiMessage{Role: "user", Content: p.Content, Images: p.Images})
 
 	// 保存用户消息
 	userMsg := models.BackendAiChatMessage{
@@ -578,6 +628,7 @@ func (c *BackendAiChatController) Send() {
 		SessionID:  session.ID,
 		Role:       "user",
 		Content:    p.Content,
+		Images:     marshalImages(p.Images),
 		CreateTime: time.Now(),
 	}
 	_, _ = models.Orm.Insert(&userMsg)
@@ -661,7 +712,7 @@ func (c *BackendAiChatController) SendStream() {
 		c.chatJsonErr(400, 400, "参数格式错误")
 		return
 	}
-	if strings.TrimSpace(p.Content) == "" {
+	if strings.TrimSpace(p.Content) == "" && len(p.Images) == 0 {
 		c.chatJsonErr(400, 400, "消息内容不能为空")
 		return
 	}
@@ -684,7 +735,7 @@ func (c *BackendAiChatController) SendStream() {
 	systemPrompt := loadSystemPrompt(claims)
 
 	messages := loadHistory(session.ID)
-	messages = append(messages, openaiMessage{Role: "user", Content: p.Content})
+	messages = append(messages, openaiMessage{Role: "user", Content: p.Content, Images: p.Images})
 
 	// 保存用户消息
 	userMsg := models.BackendAiChatMessage{
@@ -692,6 +743,7 @@ func (c *BackendAiChatController) SendStream() {
 		SessionID:  session.ID,
 		Role:       "user",
 		Content:    p.Content,
+		Images:     marshalImages(p.Images),
 		CreateTime: time.Now(),
 	}
 	_, _ = models.Orm.Insert(&userMsg)
@@ -842,7 +894,7 @@ func callAITools(provider models.BackendAiProvider, model string, systemPrompt s
 		}
 		reqBody := map[string]interface{}{
 			"model":    model,
-			"messages": reqMessages,
+			"messages": openAIMessages(reqMessages),
 		}
 		if len(tools) > 0 {
 			reqBody["tools"] = tools
@@ -1024,7 +1076,7 @@ func callOpenAIStreamTools(provider models.BackendAiProvider, model string, syst
 	}
 	reqBody := map[string]interface{}{
 		"model":    model,
-		"messages": reqMessages,
+		"messages": openAIMessages(reqMessages),
 		"stream":   true,
 	}
 	if len(tools) > 0 {
diff --git a/go/docs/sql/alter_backend_ai_chat_message_images.sql b/go/docs/sql/alter_backend_ai_chat_message_images.sql
new file mode 100644
index 0000000..fe9121c
--- /dev/null
+++ b/go/docs/sql/alter_backend_ai_chat_message_images.sql
@@ -0,0 +1,3 @@
+-- 为 AI 聊天消息表增加图片字段（用户上传的图片，base64 dataURL 的 JSON 数组）
+ALTER TABLE `yz_backend_ai_chat_message`
+  ADD COLUMN `images` TEXT NULL COMMENT '用户上传的图片（base64 dataURL 的 JSON 数组）';
diff --git a/go/models/backend_ai_chat_message.go b/go/models/backend_ai_chat_message.go
index f07c8a9..4523554 100644
--- a/go/models/backend_ai_chat_message.go
+++ b/go/models/backend_ai_chat_message.go
@@ -9,6 +9,8 @@ type BackendAiChatMessage struct {
 	SessionID  uint64    `orm:"column(session_id)" json:"session_id"`
 	Role       string    `orm:"column(role);size(20)" json:"role"` // user / assistant
 	Content    string    `orm:"column(content);type(text)" json:"content"`
+	// Images 用户上传的图片（base64 dataURL 的 JSON 数组），仅 user 消息使用
+	Images string `orm:"column(images);type(text)" json:"images"`
 	// Tokens 本次响应消耗的 token 总数（0 表示未统计到）
 	Tokens int `orm:"column(tokens)" json:"tokens"`
 	// DurationMs AI 响应耗时（毫秒，含工具调用轮次）