diff --git a/pages/aigc/chat/index.vue b/pages/aigc/chat/index.vue
index 8271322..58afd7c 100644
--- a/pages/aigc/chat/index.vue
+++ b/pages/aigc/chat/index.vue
@@ -5,6 +5,7 @@ import type {ChatMessage, ChatMessageId, ChatSessionId} from "~/typings/llm";
 import {useHistory} from "~/composables/useHistory";
 import {uuidv4} from "@uniiem/uuid";
 import {useLLM} from "~/composables/useLLM";
+import {objectTrimmer} from "~/utils/object-trimmer";
 
 useHead({
   title: '聊天 | XSH AI'
@@ -79,6 +80,13 @@ const handleClickCreateSession = () => {
   ])
   // 切换到新的会话
   selectCurrentSessionId(sessionId)
+  nextTick(() => {
+    insetMessage({
+      id: uuidv4(),
+      role: 'assistant',
+      content: '你好，有什么可以帮助你的吗？',
+    })
+  })
 }
 
 /**
@@ -117,7 +125,14 @@ const handleClickSend = (event: any) => {
     content: '',
   })
   // 请求模型回复
-  useLLM(getMessages(), {
+  const trimmedMessages = objectTrimmer<ChatMessage>(
+      getMessages(),
+      200,
+      {
+        participatingFields: ['content']
+      }
+  )
+  useLLM(trimmedMessages, {
     modelTag: 'spark3_5'
   }).then(reply => {
     modifyMessageContent(assistantReplyId, reply)
@@ -181,19 +196,21 @@ onMounted(() => {
                 shadow-sidebar border-r border-transparent dark:border-neutral-700">
       <div class="flex-1 flex flex-col overflow-auto overflow-x-hidden">
         <!-- list -->
-        <div class="flex flex-col gap-3">
+        <div class="flex flex-col gap-3 relative">
           <!-- ClientOnly avoids hydrate exception -->
           <ClientOnly>
-            <ChatItem
-                v-for="(session, i) in chatSessions"
-                :chat-session="session" :key="i"
-                :active="session.id === currentSessionId"
-                @click="selectCurrentSessionId(session.id)"
-                @remove="() => {
+            <TransitionGroup name="chat-item">
+              <ChatItem
+                  v-for="session in chatSessions"
+                  :chat-session="session" :key="session.id"
+                  :active="session.id === currentSessionId"
+                  @click="selectCurrentSessionId(session.id)"
+                  @remove="() => {
                   chatSessions.splice(chatSessions.findIndex(s => s.id === session.id), 1)
                   session.id === currentSessionId && selectCurrentSessionId()
                 }"
-            />
+              />
+            </TransitionGroup>
           </ClientOnly>
         </div>
       </div>
@@ -265,4 +282,19 @@ onMounted(() => {
 .message-enter-from {
   @apply translate-y-4 opacity-0;
 }
+
+.chat-item-move,
+.chat-item-enter-active,
+.chat-item-leave-active {
+  @apply transition-all duration-300;
+}
+
+.chat-item-enter-from,
+.chat-item-leave-to {
+  @apply opacity-0 scale-90;
+}
+
+.chat-item-leave-active {
+  @apply absolute inset-x-0;
+}
 </style>
\ No newline at end of file
diff --git a/utils/object-trimmer.ts b/utils/object-trimmer.ts
new file mode 100644
index 0000000..726313d
--- /dev/null
+++ b/utils/object-trimmer.ts
@@ -0,0 +1,26 @@
+const objectTrimmer = <T>(
+  objectList: T[],
+  length: number,
+  {
+    participatingFields = [],
+    trimFromStart = true
+  }: {
+    participatingFields: (keyof T)[],
+    trimFromStart?: boolean
+  }) => {
+  let participatingLength = 0
+  let i = objectList.length - 1
+  while (i >= 0) {
+    participatingLength = 0
+    for (const field of participatingFields) {
+      participatingLength += JSON.stringify(objectList[i][field]).length
+      if (participatingLength > length) {
+        break
+      }
+    }
+    i--
+  }
+  return trimFromStart ? objectList.slice(i + 1) : objectList.slice(0, i + 1)
+}
+
+export {objectTrimmer}