diff --git a/api/modules/index.ts b/api/modules/index.ts
index f3b2fb3..19641c1 100644
--- a/api/modules/index.ts
+++ b/api/modules/index.ts
@@ -56,6 +56,13 @@ async function getStaticModules(): Promise<ApiModule[]> {
     console.warn('[ModuleLoader] Failed to load remote module:', e)
   }
 
+  try {
+    const { createOpencodeModule } = await import('./opencode/index.js')
+    modules.push(createOpencodeModule())
+  } catch (e) {
+    console.warn('[ModuleLoader] Failed to load opencode module:', e)
+  }
+
   modules.sort((a, b) => {
     const orderA = a.metadata.order ?? 0
     const orderB = b.metadata.order ?? 0
@@ -74,3 +81,4 @@ export * from './pydemos/index.js'
 export * from './document-parser/index.js'
 export * from './ai/index.js'
 export * from './remote/index.js'
+export * from './opencode/index.js'
diff --git a/api/modules/opencode/index.ts b/api/modules/opencode/index.ts
new file mode 100644
index 0000000..e091bb1
--- /dev/null
+++ b/api/modules/opencode/index.ts
@@ -0,0 +1,20 @@
+import type { Router } from 'express'
+import type { ServiceContainer } from '../../infra/container.js'
+import { createApiModule } from '../../infra/createModule.js'
+import { OPENCODE_MODULE } from '../../../shared/modules/opencode/index.js'
+import { createOpencodeRoutes } from './routes.js'
+
+export * from './routes.js'
+
+export const createOpencodeModule = () => {
+  return createApiModule({
+    ...OPENCODE_MODULE,
+    version: OPENCODE_MODULE.version || '1.0.0',
+  }, {
+    routes: (_container: ServiceContainer): Router => {
+      return createOpencodeRoutes()
+    },
+  })
+}
+
+export default createOpencodeModule
\ No newline at end of file
diff --git a/api/modules/opencode/routes.ts b/api/modules/opencode/routes.ts
new file mode 100644
index 0000000..f351d18
--- /dev/null
+++ b/api/modules/opencode/routes.ts
@@ -0,0 +1,223 @@
+import { Router } from 'express'
+import { createOpencodeClient } from '@opencode-ai/sdk'
+
+const OPENCODE_URL = 'http://localhost:4096'
+
+async function getClient() {
+  console.log('[OpenCode] Creating client for URL:', OPENCODE_URL)
+  return createOpencodeClient({
+    baseUrl: OPENCODE_URL,
+  })
+}
+
+export function createOpencodeRoutes(): Router {
+  const router = Router()
+
+  router.get('/', async (req, res) => {
+    const action = req.query.action as string | undefined
+    
+    try {
+      const client = await getClient()
+      
+      if (action === 'list-sessions') {
+        const response = await client.session.list()
+        const sessions = (response.data || []).map((session: { id: string; title?: string; createdAt?: string }) => ({
+          id: session.id,
+          title: session.title || 'New Chat',
+          createdAt: session.createdAt ? new Date(session.createdAt).getTime() : Date.now(),
+        }))
+        res.json({ sessions })
+        return
+      }
+      
+      res.status(400).json({ error: 'Unknown action' })
+    } catch (error: unknown) {
+      console.error('API error:', error)
+      const errorMessage = error instanceof Error ? error.message : 'Unknown error'
+      res.status(500).json({ error: errorMessage })
+    }
+  })
+
+  router.post('/', async (req, res) => {
+    try {
+      const body = req.body
+      const { action, sessionId, title, text, attachments } = body
+      console.log('[OpenCode] Received action:', action, 'sessionId:', sessionId)
+      
+      const client = await getClient()
+      console.log('[OpenCode] Client created successfully')
+      
+      if (action === 'create-session') {
+        try {
+          const response = await client.session.create({
+            body: { title: title || 'New Chat' },
+          })
+          
+          if (response.error) {
+            res.status(500).json({ error: 'OpenCode error', details: response.error })
+            return
+          }
+          
+          const sessionData = response.data as { id: string; title?: string; createdAt?: string } | undefined
+          if (sessionData) {
+            res.json({
+              session: {
+                id: sessionData.id,
+                title: sessionData.title,
+                createdAt: sessionData.createdAt ? new Date(sessionData.createdAt).getTime() : Date.now(),
+              },
+            })
+            return
+          }
+          res.status(500).json({ error: 'Failed to create session - no data' })
+          return
+        } catch (e: unknown) {
+          console.error('Create session exception:', e)
+          const errorMessage = e instanceof Error ? e.message : 'Unknown error'
+          res.status(500).json({ error: errorMessage, exception: true })
+          return
+        }
+      }
+      
+      if (action === 'delete-session') {
+        const response = await client.session.delete({
+          path: { id: sessionId },
+        })
+        res.json({ success: response.data })
+        return
+      }
+      
+      if (action === 'get-session') {
+        const response = await client.session.get({
+          path: { id: sessionId },
+        })
+        
+        if (response.data) {
+          res.json({
+            title: response.data.title || 'New Chat',
+          })
+          return
+        }
+        res.status(404).json({ error: 'Session not found' })
+        return
+      }
+      
+      if (action === 'get-messages') {
+        const limit = body.limit || 20
+        
+        const response = await client.session.messages({
+          path: { id: sessionId },
+          query: { limit }
+        })
+        
+        const messages = (response.data || []).map((item: { info?: { id?: string; role?: string; content?: string; createdAt?: string }; content?: string; parts?: unknown[]; id?: string; role?: string }) => {
+          let content = item.info?.content || item.content || ''
+          
+          const parts = item.parts as Array<{ type: string; text?: string }> | undefined
+          if (parts && parts.length > 0) {
+            const textParts = parts
+              .filter((p) => p.type === 'text')
+              .map((p) => p.text)
+              .join('')
+            if (textParts) {
+              content = textParts
+            }
+          }
+          
+          return {
+            id: item.info?.id || item.id,
+            role: item.info?.role || item.role,
+            content: content,
+            parts: item.parts || [],
+            createdAt: item.info?.createdAt,
+          }
+        })
+        
+        const hasMore = messages.length >= limit
+        
+        res.json({ messages, hasMore })
+        return
+      }
+      
+      if (action === 'prompt') {
+        const parts: Array<{ type: 'text'; text: string } | { type: 'file'; url: string; name: string; mime: string }> = []
+        
+        if (attachments && attachments.length > 0) {
+          for (const att of attachments as Array<{ url: string; name: string; mediaType: string }>) {
+            parts.push({
+              type: 'file',
+              url: att.url,
+              name: att.name,
+              mime: att.mediaType,
+            })
+          }
+        }
+        
+        parts.push({ type: 'text', text })
+        
+        try {
+          const response = await client.session.prompt({
+            path: { id: sessionId },
+            body: { parts },
+          })
+          
+          if (response.data) {
+            res.json({
+              message: {
+                id: (response.data.info as { id?: string })?.id || crypto.randomUUID(),
+                role: (response.data.info as { role?: string })?.role || 'assistant',
+                content: '',
+                parts: response.data.parts || [],
+                createdAt: new Date().toISOString(),
+              },
+            })
+            return
+          }
+          
+          res.status(500).json({ error: 'Failed to get response', details: response.error })
+          return
+        } catch (e: unknown) {
+          console.error('Prompt exception:', e)
+          const errorMessage = e instanceof Error ? e.message : 'Unknown error'
+          res.status(500).json({ error: errorMessage })
+          return
+        }
+      }
+      
+      if (action === 'summarize-session') {
+        try {
+          await client.session.summarize({
+            path: { id: sessionId },
+          })
+          
+          const response = await client.session.get({
+            path: { id: sessionId },
+          })
+          
+          if (response.data) {
+            res.json({
+              title: response.data.title || 'New Chat',
+            })
+            return
+          }
+          
+          res.status(500).json({ error: 'Failed to get session' })
+          return
+        } catch (e: unknown) {
+          console.error('Summarize error:', e)
+          const errorMessage = e instanceof Error ? e.message : 'Unknown error'
+          res.status(500).json({ error: errorMessage })
+          return
+        }
+      }
+      
+      res.status(400).json({ error: 'Unknown action' })
+    } catch (error: unknown) {
+      console.error('API error:', error)
+      const errorMessage = error instanceof Error ? error.message : 'Unknown error'
+      res.status(500).json({ error: errorMessage })
+    }
+  })
+
+  return router
+}
\ No newline at end of file
diff --git a/shared/modules/opencode/index.ts b/shared/modules/opencode/index.ts
index d91de61..66267b6 100644
--- a/shared/modules/opencode/index.ts
+++ b/shared/modules/opencode/index.ts
@@ -7,6 +7,6 @@ export const OPENCODE_MODULE = defineModule({
   order: 15,
   version: '1.0.0',
   backend: {
-    enabled: false,
+    enabled: true,
   },
 })
diff --git a/src/components/chat/Chat.tsx b/src/components/chat/Chat.tsx
new file mode 100644
index 0000000..e5880d7
--- /dev/null
+++ b/src/components/chat/Chat.tsx
@@ -0,0 +1,243 @@
+import { useRef, useState, useCallback, useEffect } from 'react'
+import {
+  AlertDialog,
+  AlertDialogAction,
+  AlertDialogCancel,
+  AlertDialogContent,
+  AlertDialogDescription,
+  AlertDialogFooter,
+  AlertDialogHeader,
+  AlertDialogTitle,
+} from './ui/AlertDialog'
+import { Messages } from './Messages'
+import { MultimodalInput } from './MultimodalInput'
+import { generateUUID } from '@/lib/utils'
+import { Eraser } from 'lucide-react'
+
+type Status = 'submitted' | 'streaming' | 'ready' | 'error'
+
+interface Attachment {
+  url: string
+  name: string
+  contentType: string
+}
+
+interface ChatMessage {
+  id: string
+  role: 'user' | 'assistant' | 'system'
+  content: string
+  parts: Array<{ type: string; text?: string }>
+  createdAt?: Date
+}
+
+const OPENCODE_API = '/api/opencode'
+const INITIAL_MESSAGE_LIMIT = 20
+
+export function Chat({
+  id,
+  initialMessages,
+  onClear,
+}: {
+  id: string
+  initialMessages: ChatMessage[]
+  onClear?: () => void
+}) {
+  const messagesEndRef = useRef<HTMLDivElement>(null)
+
+  const [messages, setMessages] = useState<ChatMessage[]>(initialMessages)
+  const [hasMoreMessages, setHasMoreMessages] = useState(false)
+  const [input, setInput] = useState<string>('')
+  const [showCreditCardAlert, setShowCreditCardAlert] = useState(false)
+  const [status, setStatus] = useState<Status>('ready')
+  const [attachments, setAttachments] = useState<Attachment[]>([])
+  const [showInputAtBottom, setShowInputAtBottom] = useState(false)
+
+  const scrollToBottom = useCallback(() => {
+    messagesEndRef.current?.scrollIntoView({ behavior: 'auto' })
+  }, [])
+
+  const loadMessages = useCallback(async () => {
+    try {
+      const res = await fetch(OPENCODE_API, {
+        method: 'POST',
+        headers: { 'Content-Type': 'application/json' },
+        body: JSON.stringify({ 
+          action: 'get-messages', 
+          sessionId: id,
+          limit: INITIAL_MESSAGE_LIMIT
+        }),
+      })
+      if (res.ok) {
+        const data = await res.json()
+        const newMessages = data.messages || []
+        setMessages(newMessages)
+        setHasMoreMessages(data.hasMore ?? newMessages.length >= INITIAL_MESSAGE_LIMIT)
+        setTimeout(scrollToBottom, 100)
+      }
+    } catch (error) {
+      console.error('Failed to load messages:', error)
+    }
+  }, [id, scrollToBottom])
+
+  const loadMoreMessages = useCallback(async () => {
+    if (messages.length === 0) return
+    
+    const currentCount = messages.length
+    const newLimit = currentCount + INITIAL_MESSAGE_LIMIT
+    
+    try {
+      const res = await fetch(OPENCODE_API, {
+        method: 'POST',
+        headers: { 'Content-Type': 'application/json' },
+        body: JSON.stringify({ 
+          action: 'get-messages', 
+          sessionId: id,
+          limit: newLimit
+        }),
+      })
+      if (res.ok) {
+        const data = await res.json()
+        const newMessages = data.messages || []
+        
+        setMessages(prev => {
+          const existingIds = new Set(prev.map(m => m.id))
+          const uniqueNew = newMessages.filter((m: ChatMessage) => !existingIds.has(m.id))
+          return [...uniqueNew, ...prev]
+        })
+        
+        setHasMoreMessages(data.hasMore ?? newMessages.length >= newLimit)
+      }
+    } catch (error) {
+      console.error('Failed to load more messages:', error)
+    }
+  }, [id, messages])
+
+  useEffect(() => {
+    if (id) {
+      loadMessages()
+    }
+  }, [id, loadMessages])
+
+  const handleSendMessage = useCallback(async (text: string, atts: Attachment[]) => {
+    const userMessage: ChatMessage = {
+      id: generateUUID(),
+      role: 'user',
+      content: text,
+      parts: [],
+      createdAt: new Date(),
+    }
+
+    setMessages(prev => [...prev, userMessage])
+    setStatus('submitted')
+
+    try {
+      const res = await fetch(OPENCODE_API, {
+        method: 'POST',
+        headers: { 'Content-Type': 'application/json' },
+        body: JSON.stringify({
+          action: 'prompt',
+          sessionId: id,
+          text,
+          attachments: atts.map(a => ({
+            url: a.url,
+            name: a.name,
+            mediaType: a.contentType,
+          })),
+        }),
+      })
+
+      if (!res.ok) {
+        throw new Error(await res.text())
+      }
+
+      const data = await res.json()
+
+      if (data.message) {
+        setMessages(prev => [...prev, data.message])
+        setShowInputAtBottom(true)
+      }
+
+      setStatus('ready')
+    } catch (error: unknown) {
+      console.error('Send message error:', error)
+      setStatus('error')
+      
+      const errorMessage = error instanceof Error ? error.message : 'Failed to send message'
+      if (errorMessage.includes('credit card')) {
+        setShowCreditCardAlert(true)
+      }
+    }
+  }, [id])
+
+  const handleStop = useCallback(() => {
+    setStatus('ready')
+  }, [])
+
+  return (
+    <>
+      <div className="overscroll-behavior-contain flex h-full min-w-0 touch-pan-y flex-col bg-background">
+        {onClear && messages.length > 0 && (
+          <div className="absolute top-4 right-4 z-10">
+            <button
+              onClick={onClear}
+              className="flex items-center rounded-md bg-primary p-2 text-primary-foreground hover:bg-primary/90"
+            >
+              <Eraser className="h-4 w-4" />
+            </button>
+          </div>
+        )}
+        <Messages
+          messages={messages}
+          status={status}
+          hasMoreMessages={hasMoreMessages}
+          loadMoreMessages={loadMoreMessages}
+        />
+
+        <div ref={messagesEndRef} />
+        <div
+          className={`mx-auto flex w-full max-w-4xl gap-2 px-2 pb-3 transition-all duration-300 md:px-4 md:pb-4 ${
+            showInputAtBottom || messages.length > 0
+              ? 'sticky bottom-0'
+              : 'absolute bottom-[40%] left-0 right-0'
+          }`}
+        >
+          <MultimodalInput
+            attachments={attachments}
+            chatId={id}
+            input={input}
+            messages={messages}
+            sendMessage={handleSendMessage}
+            setAttachments={setAttachments}
+            setInput={setInput}
+            status={status}
+            stop={handleStop}
+          />
+        </div>
+      </div>
+
+      <AlertDialog
+        onOpenChange={setShowCreditCardAlert}
+        open={showCreditCardAlert}
+      >
+        <AlertDialogContent>
+          <AlertDialogHeader>
+            <AlertDialogTitle>API 配置需要</AlertDialogTitle>
+            <AlertDialogDescription>
+              请在环境变量中配置您的 AI API 密钥。
+            </AlertDialogDescription>
+          </AlertDialogHeader>
+          <AlertDialogFooter>
+            <AlertDialogCancel>取消</AlertDialogCancel>
+            <AlertDialogAction
+              onClick={() => {
+                setShowCreditCardAlert(false)
+              }}
+            >
+              确定
+            </AlertDialogAction>
+          </AlertDialogFooter>
+        </AlertDialogContent>
+      </AlertDialog>
+    </>
+  )
+}
\ No newline at end of file
diff --git a/src/components/chat/Greeting.tsx b/src/components/chat/Greeting.tsx
new file mode 100644
index 0000000..2442c3a
--- /dev/null
+++ b/src/components/chat/Greeting.tsx
@@ -0,0 +1,9 @@
+export function Greeting() {
+  return (
+    <div className="mx-auto mt-64 max-w-2xl px-4 text-center">
+      <h1 className="text-3xl font-bold tracking-tight">
+        开始今天的工作吧！
+      </h1>
+    </div>
+  )
+}
\ No newline at end of file
diff --git a/src/components/chat/Message.tsx b/src/components/chat/Message.tsx
new file mode 100644
index 0000000..40212bc
--- /dev/null
+++ b/src/components/chat/Message.tsx
@@ -0,0 +1,88 @@
+import { memo } from 'react'
+import { cn } from '@/lib/utils'
+import { ArrowDownIcon, SparklesIcon } from 'lucide-react'
+
+interface MessageProps {
+  message: {
+    id: string
+    role: 'user' | 'assistant' | 'system'
+    content: string
+    parts?: Array<{ type: string; text?: string }>
+  }
+  isLoading?: boolean
+}
+
+function PureMessage({ message, isLoading }: MessageProps) {
+  const isUser = message.role === 'user'
+
+  return (
+    <div
+      className={cn(
+        'flex w-full gap-4 px-4',
+        isUser ? 'justify-end' : 'justify-start'
+      )}
+    >
+      <div className={cn(
+        'flex max-w-[80%] flex-col gap-1 rounded-lg p-4',
+        isUser ? 'bg-primary text-primary-foreground' : 'bg-muted/50'
+      )}>
+        {message.parts?.map((part: { type: string; text?: string }, i: number) => {
+          const safeString = (val: unknown): string => {
+            if (val === null || val === undefined) return ''
+            if (typeof val === 'string') return val
+            if (typeof val === 'object') return JSON.stringify(val, null, 2)
+            return String(val)
+          }
+          
+          if (part.type === 'text') {
+            return (
+              <div key={i} className={cn('whitespace-pre-wrap text-sm', isUser && 'text-primary-foreground')}>
+                {safeString(part.text)}
+              </div>
+            )
+          }
+          
+          if (part.type === 'reasoning') {
+            return (
+              <div key={i} className="rounded border border-gray-500/30 bg-gray-500/10 p-2 text-xs text-gray-600 dark:text-gray-400">
+                <div className="flex items-center gap-1 font-semibold">
+                  <SparklesIcon className="size-3" />
+                  Thinking
+                </div>
+                <div className="mt-1 whitespace-pre-wrap">{safeString(part.text)}</div>
+              </div>
+            )
+          }
+          
+          return null
+        })}
+        {(!message.parts || message.parts.length === 0) && message.content && (
+          <div className={cn('whitespace-pre-wrap text-sm', isUser && 'text-primary-foreground')}>{message.content}</div>
+        )}
+        {isLoading && (
+          <div className={cn('flex items-center gap-1 text-xs', isUser ? 'text-primary-foreground/70' : 'text-muted-foreground')}>
+            <span className="animate-pulse">Thinking</span>
+            <ArrowDownIcon className="size-3 animate-bounce" />
+          </div>
+        )}
+      </div>
+    </div>
+  )
+}
+
+export const PreviewMessage = memo(PureMessage)
+
+export function ThinkingMessage() {
+  return (
+    <div className="flex w-full gap-4 px-4">
+      <div className="flex flex-col gap-1 rounded-lg bg-muted/50 p-4">
+        <div className="flex items-center gap-2 text-sm text-muted-foreground">
+          <span className="animate-pulse">Thinking</span>
+          <span className="size-1.5 animate-bounce rounded-full bg-muted-foreground" />
+          <span className="size-1.5 animate-bounce rounded-full bg-muted-foreground [animation-delay:0.2s]" />
+          <span className="size-1.5 animate-bounce rounded-full bg-muted-foreground [animation-delay:0.4s]" />
+        </div>
+      </div>
+    </div>
+  )
+}
\ No newline at end of file
diff --git a/src/components/chat/Messages.tsx b/src/components/chat/Messages.tsx
new file mode 100644
index 0000000..d8e04a6
--- /dev/null
+++ b/src/components/chat/Messages.tsx
@@ -0,0 +1,103 @@
+import { ArrowDownIcon, Loader2Icon } from 'lucide-react'
+import { useState, useEffect } from 'react'
+import { useMessages } from '@/hooks/useMessages'
+import { Greeting } from './Greeting'
+import { PreviewMessage, ThinkingMessage } from './Message'
+
+type Status = 'submitted' | 'streaming' | 'ready' | 'error'
+
+interface ChatMessage {
+  id: string
+  role: 'user' | 'assistant' | 'system'
+  content: string
+  parts: Array<{ type: string; text?: string }>
+  createdAt?: Date
+}
+
+type MessagesProps = {
+  messages: ChatMessage[]
+  status: Status
+  hasMoreMessages?: boolean
+  loadMoreMessages?: () => void
+}
+
+export function Messages({ messages, status, hasMoreMessages, loadMoreMessages }: MessagesProps) {
+  const [isLoadingMore, setIsLoadingMore] = useState(false)
+  
+  const {
+    containerRef: messagesContainerRef,
+    endRef: messagesEndRef,
+    isAtBottom,
+    scrollToBottom,
+  } = useMessages({ status })
+
+  useEffect(() => {
+    if (messages.length > 0) {
+      const container = messagesContainerRef.current
+      if (container) {
+        container.scrollTop = container.scrollHeight
+      }
+    }
+  }, [messages, messagesContainerRef])
+
+  const handleLoadMore = async () => {
+    if (!loadMoreMessages || isLoadingMore) return
+    setIsLoadingMore(true)
+    await loadMoreMessages()
+    setIsLoadingMore(false)
+  }
+
+  return (
+    <div className="relative flex-1 bg-background">
+      <div
+        className="absolute inset-0 touch-pan-y overflow-y-auto bg-background"
+        ref={messagesContainerRef}
+      >
+        <div className="mx-auto flex min-w-0 max-w-4xl flex-col gap-4 px-2 py-4 md:gap-6 md:px-4">
+          {hasMoreMessages && (
+            <div className="flex justify-center py-2">
+              <button
+                onClick={handleLoadMore}
+                disabled={isLoadingMore}
+                className="flex items-center gap-2 rounded-full border bg-background px-4 py-2 text-sm text-muted-foreground hover:bg-muted disabled:opacity-50"
+              >
+                {isLoadingMore && <Loader2Icon className="size-4 animate-spin" />}
+                {isLoadingMore ? 'Loading...' : 'Load more messages'}
+              </button>
+            </div>
+          )}
+
+          {messages.length === 0 && <Greeting />}
+
+          {messages.map((message, index) => (
+            <PreviewMessage
+              key={message.id}
+              message={message}
+              isLoading={status === 'streaming' && messages.length - 1 === index}
+            />
+          ))}
+
+          {status === 'submitted' && <ThinkingMessage />}
+
+          <div
+            className="min-h-[24px] min-w-[24px] shrink-0"
+            ref={messagesEndRef}
+          />
+        </div>
+      </div>
+
+      <button
+        aria-label="Scroll to bottom"
+        className={`absolute bottom-4 left-1/2 z-10 -translate-x-1/2 rounded-full border bg-background p-2 shadow-lg transition-all hover:bg-muted ${
+          isAtBottom
+            ? 'pointer-events-none scale-0 opacity-0'
+            : 'pointer-events-auto scale-100 opacity-100'
+        }`}
+        onClick={() => scrollToBottom('smooth')}
+        type="button"
+      >
+        <ArrowDownIcon className="size-4" />
+      </button>
+    </div>
+  )
+}
\ No newline at end of file
diff --git a/src/components/chat/MultimodalInput.tsx b/src/components/chat/MultimodalInput.tsx
new file mode 100644
index 0000000..c37839a
--- /dev/null
+++ b/src/components/chat/MultimodalInput.tsx
@@ -0,0 +1,165 @@
+import { useCallback, useEffect, useRef } from 'react'
+import { cn } from '@/lib/utils'
+import { ArrowUpIcon, StopIcon } from './icons'
+import { Button } from './ui/Button'
+
+type Status = 'submitted' | 'streaming' | 'ready' | 'error'
+
+interface Attachment {
+  url: string
+  name: string
+  contentType: string
+}
+
+interface ChatMessage {
+  id: string
+  role: 'user' | 'assistant' | 'system'
+  content: string
+  parts: unknown[]
+  createdAt?: Date
+}
+
+interface MultimodalInputProps {
+  chatId: string
+  input: string
+  setInput: (value: string) => void
+  status: Status
+  stop: () => void
+  attachments: Attachment[]
+  setAttachments: (attachments: Attachment[]) => void
+  messages: ChatMessage[]
+  sendMessage: (text: string, attachments: Attachment[]) => Promise<void>
+  className?: string
+}
+
+export function MultimodalInput({
+  chatId,
+  input,
+  setInput,
+  status,
+  stop,
+  attachments,
+  setAttachments,
+  sendMessage,
+  className,
+}: MultimodalInputProps) {
+  const textareaRef = useRef<HTMLTextAreaElement>(null)
+
+  const adjustHeight = useCallback(() => {
+    if (textareaRef.current) {
+      textareaRef.current.style.height = '44px'
+    }
+  }, [])
+
+  useEffect(() => {
+    if (textareaRef.current) {
+      adjustHeight()
+    }
+  }, [adjustHeight])
+
+  const resetHeight = useCallback(() => {
+    if (textareaRef.current) {
+      textareaRef.current.style.height = '44px'
+    }
+  }, [])
+
+  const handleInput = (event: React.ChangeEvent<HTMLTextAreaElement>) => {
+    setInput(event.target.value)
+  }
+
+  const submitForm = useCallback(() => {
+    if (!input.trim() && attachments.length === 0) return
+
+    sendMessage(input, attachments)
+
+    setAttachments([])
+    resetHeight()
+    setInput('')
+
+    textareaRef.current?.focus()
+  }, [input, setInput, attachments, sendMessage, setAttachments, resetHeight])
+
+  const handleKeyDown = (event: React.KeyboardEvent<HTMLTextAreaElement>) => {
+    if (event.key === 'Enter' && !event.shiftKey) {
+      event.preventDefault()
+      if (!input.trim() && attachments.length === 0) {
+        return
+      }
+      if (status !== 'ready') {
+        console.warn('Please wait for the model to finish its response!')
+      } else {
+        submitForm()
+      }
+    }
+  }
+
+  useEffect(() => {
+    if (textareaRef.current) {
+      const target = textareaRef.current
+      target.style.height = '44px'
+      const scrollHeight = target.scrollHeight
+      if (scrollHeight > 44) {
+        target.style.height = `${Math.min(scrollHeight, 200)}px`
+      }
+    }
+  }, [input])
+
+  return (
+    <div className={cn('relative flex w-full flex-col gap-4', className)}>
+      <div className="relative flex w-full items-end gap-2 rounded-xl border border-border bg-background p-3 shadow-xs transition-all duration-200 focus-within:border-border hover:border-muted-foreground/50">
+        {attachments.length > 0 && (
+          <div className="flex flex-row items-end gap-2 overflow-x-scroll">
+            {attachments.map((attachment) => (
+              <div
+                key={attachment.url}
+                className="relative flex items-center gap-1 rounded-md bg-muted px-2 py-1 text-xs"
+              >
+                <span className="max-w-[100px] truncate">{attachment.name}</span>
+                <button
+                  className="text-muted-foreground hover:text-foreground"
+                  onClick={() => {
+                    setAttachments(attachments.filter((a) => a.url !== attachment.url))
+                  }}
+                >
+                  ×
+                </button>
+              </div>
+            ))}
+          </div>
+        )}
+        
+        <textarea
+          ref={textareaRef}
+          className="max-h-[200px] min-h-[44px] w-full resize-none border-0 bg-transparent p-2 text-base outline-none placeholder:text-muted-foreground [-ms-overflow-style:none] [scrollbar-width:none]"
+          style={{ height: '44px' }}
+          value={input}
+          onChange={handleInput}
+          onKeyDown={handleKeyDown}
+          placeholder="发送消息..."
+          rows={1}
+        />
+        
+        <div className="flex items-center gap-1">
+          {status === 'submitted' ? (
+            <Button
+              className="size-8 rounded-full bg-foreground p-1 text-background transition-colors duration-200 hover:bg-foreground/90"
+              onClick={() => {
+                stop()
+              }}
+            >
+              <StopIcon size={14} />
+            </Button>
+          ) : (
+            <Button
+              className="size-8 rounded-full bg-primary text-primary-foreground transition-colors duration-200 hover:bg-primary/90 disabled:bg-muted disabled:text-muted-foreground"
+              disabled={!input.trim() && attachments.length === 0}
+              onClick={submitForm}
+            >
+              <ArrowUpIcon size={14} />
+            </Button>
+          )}
+        </div>
+      </div>
+    </div>
+  )
+}
\ No newline at end of file
diff --git a/src/components/chat/icons.tsx b/src/components/chat/icons.tsx
new file mode 100644
index 0000000..2f7736f
--- /dev/null
+++ b/src/components/chat/icons.tsx
@@ -0,0 +1,25 @@
+import {
+  ArrowUp,
+  ArrowDown,
+  Paperclip,
+  StopCircle,
+  ChevronDown,
+  Check,
+  Plus,
+  Trash,
+  PanelLeftClose,
+  PanelLeft,
+} from 'lucide-react'
+
+export {
+  ArrowUp as ArrowUpIcon,
+  ArrowDown as ArrowDownIcon,
+  Paperclip as PaperclipIcon,
+  StopCircle as StopIcon,
+  ChevronDown as ChevronDownIcon,
+  Check as CheckIcon,
+  Plus as PlusIcon,
+  Trash as TrashIcon,
+  PanelLeftClose as PanelLeftCloseIcon,
+  PanelLeft as PanelLeftOpenIcon,
+}
\ No newline at end of file
diff --git a/src/components/chat/ui/AlertDialog.tsx b/src/components/chat/ui/AlertDialog.tsx
new file mode 100644
index 0000000..719d6d5
--- /dev/null
+++ b/src/components/chat/ui/AlertDialog.tsx
@@ -0,0 +1,132 @@
+import * as React from 'react'
+import * as AlertDialogPrimitive from '@radix-ui/react-alert-dialog'
+import { cn } from '@/lib/utils'
+import { buttonVariants } from './Button'
+
+const AlertDialog = AlertDialogPrimitive.Root
+const AlertDialogTrigger = AlertDialogPrimitive.Trigger
+const AlertDialogPortal = AlertDialogPrimitive.Portal
+
+const AlertDialogOverlay = React.forwardRef<
+  React.ElementRef<typeof AlertDialogPrimitive.Overlay>,
+  React.ComponentPropsWithoutRef<typeof AlertDialogPrimitive.Overlay>
+>(({ className, ...props }, ref) => (
+  <AlertDialogPrimitive.Overlay
+    className={cn(
+      'fixed inset-0 z-50 bg-black/80 data-[state=open]:animate-in data-[state=closed]:animate-out data-[state=closed]:fade-out-0 data-[state=open]:fade-in-0',
+      className
+    )}
+    {...props}
+    ref={ref}
+  />
+))
+AlertDialogOverlay.displayName = AlertDialogPrimitive.Overlay.displayName
+
+const AlertDialogContent = React.forwardRef<
+  React.ElementRef<typeof AlertDialogPrimitive.Content>,
+  React.ComponentPropsWithoutRef<typeof AlertDialogPrimitive.Content>
+>(({ className, ...props }, ref) => (
+  <AlertDialogPortal>
+    <AlertDialogOverlay />
+    <AlertDialogPrimitive.Content
+      className={cn(
+        'fixed left-[50%] top-[50%] z-50 grid w-full max-w-lg translate-x-[-50%] translate-y-[-50%] gap-4 border bg-background p-6 shadow-lg duration-200 data-[state=open]:animate-in data-[state=closed]:animate-out data-[state=closed]:fade-out-0 data-[state=open]:fade-in-0 data-[state=closed]:zoom-out-95 data-[state=open]:zoom-in-95 data-[state=closed]:slide-out-to-left-1/2 data-[state=closed]:slide-out-to-top-[48%] data-[state=open]:slide-in-from-left-1/2 data-[state=open]:slide-in-from-top-[48%] sm:rounded-lg',
+        className
+      )}
+      ref={ref}
+      {...props}
+    />
+  </AlertDialogPortal>
+))
+AlertDialogContent.displayName = AlertDialogPrimitive.Content.displayName
+
+const AlertDialogHeader = ({
+  className,
+  ...props
+}: React.HTMLAttributes<HTMLDivElement>) => (
+  <div
+    className={cn('flex flex-col space-y-2 text-center sm:text-left', className)}
+    {...props}
+  />
+)
+AlertDialogHeader.displayName = 'AlertDialogHeader'
+
+const AlertDialogFooter = ({
+  className,
+  ...props
+}: React.HTMLAttributes<HTMLDivElement>) => (
+  <div
+    className={cn(
+      'flex flex-col-reverse sm:flex-row sm:justify-end sm:space-x-2',
+      className
+    )}
+    {...props}
+  />
+)
+AlertDialogFooter.displayName = 'AlertDialogFooter'
+
+const AlertDialogTitle = React.forwardRef<
+  React.ElementRef<typeof AlertDialogPrimitive.Title>,
+  React.ComponentPropsWithoutRef<typeof AlertDialogPrimitive.Title>
+>(({ className, ...props }, ref) => (
+  <AlertDialogPrimitive.Title
+    className={cn('text-lg font-semibold', className)}
+    ref={ref}
+    {...props}
+  />
+))
+AlertDialogTitle.displayName = AlertDialogPrimitive.Title.displayName
+
+const AlertDialogDescription = React.forwardRef<
+  React.ElementRef<typeof AlertDialogPrimitive.Description>,
+  React.ComponentPropsWithoutRef<typeof AlertDialogPrimitive.Description>
+>(({ className, ...props }, ref) => (
+  <AlertDialogPrimitive.Description
+    className={cn('text-sm text-muted-foreground', className)}
+    ref={ref}
+    {...props}
+  />
+))
+AlertDialogDescription.displayName = AlertDialogPrimitive.Description.displayName
+
+const AlertDialogAction = React.forwardRef<
+  React.ElementRef<typeof AlertDialogPrimitive.Action>,
+  React.ComponentPropsWithoutRef<typeof AlertDialogPrimitive.Action>
+>(({ className, ...props }, ref) => (
+  <AlertDialogPrimitive.Action
+    className={cn(buttonVariants(), className)}
+    ref={ref}
+    {...props}
+  />
+))
+AlertDialogAction.displayName = AlertDialogPrimitive.Action.displayName
+
+const AlertDialogCancel = React.forwardRef<
+  React.ElementRef<typeof AlertDialogPrimitive.Cancel>,
+  React.ComponentPropsWithoutRef<typeof AlertDialogPrimitive.Cancel>
+>(({ className, ...props }, ref) => (
+  <AlertDialogPrimitive.Cancel
+    className={cn(
+      buttonVariants({ variant: 'outline' }),
+      'mt-2 sm:mt-0',
+      className
+    )}
+    ref={ref}
+    {...props}
+  />
+))
+AlertDialogCancel.displayName = AlertDialogPrimitive.Cancel.displayName
+
+export {
+  AlertDialog,
+  AlertDialogPortal,
+  AlertDialogOverlay,
+  AlertDialogTrigger,
+  AlertDialogContent,
+  AlertDialogHeader,
+  AlertDialogFooter,
+  AlertDialogTitle,
+  AlertDialogDescription,
+  AlertDialogAction,
+  AlertDialogCancel,
+}
\ No newline at end of file
diff --git a/src/components/chat/ui/Button.tsx b/src/components/chat/ui/Button.tsx
new file mode 100644
index 0000000..b489b17
--- /dev/null
+++ b/src/components/chat/ui/Button.tsx
@@ -0,0 +1,52 @@
+import * as React from 'react'
+import { Slot } from '@radix-ui/react-slot'
+import { cva, type VariantProps } from 'class-variance-authority'
+import { cn } from '@/lib/utils'
+
+const buttonVariants = cva(
+  'inline-flex items-center justify-center gap-2 whitespace-nowrap rounded-md text-sm font-medium transition-colors focus-visible:outline-none focus-visible:ring-1 focus-visible:ring-ring disabled:pointer-events-none disabled:opacity-50 [&_svg]:pointer-events-none [&_svg]:size-4 [&_svg]:shrink-0',
+  {
+    variants: {
+      variant: {
+        default: 'bg-primary text-primary-foreground shadow hover:bg-primary/90',
+        destructive: 'bg-destructive text-destructive-foreground shadow-sm hover:bg-destructive/90',
+        outline: 'border border-input bg-background shadow-sm hover:bg-accent hover:text-accent-foreground',
+        secondary: 'bg-secondary text-secondary-foreground shadow-sm hover:bg-secondary/80',
+        ghost: 'hover:bg-accent hover:text-accent-foreground',
+        link: 'text-primary underline-offset-4 hover:underline',
+      },
+      size: {
+        default: 'h-9 px-4 py-2',
+        sm: 'h-8 rounded-md px-3 text-xs',
+        lg: 'h-10 rounded-md px-8',
+        icon: 'h-9 w-9',
+      },
+    },
+    defaultVariants: {
+      variant: 'default',
+      size: 'default',
+    },
+  }
+)
+
+export interface ButtonProps
+  extends React.ButtonHTMLAttributes<HTMLButtonElement>,
+    VariantProps<typeof buttonVariants> {
+  asChild?: boolean
+}
+
+const Button = React.forwardRef<HTMLButtonElement, ButtonProps>(
+  ({ className, variant, size, asChild = false, ...props }, ref) => {
+    const Comp = asChild ? Slot : 'button'
+    return (
+      <Comp
+        className={cn(buttonVariants({ variant, size, className }))}
+        ref={ref}
+        {...props}
+      />
+    )
+  }
+)
+Button.displayName = 'Button'
+
+export { Button, buttonVariants }
\ No newline at end of file
diff --git a/src/hooks/useMessages.ts b/src/hooks/useMessages.ts
new file mode 100644
index 0000000..1f96d08
--- /dev/null
+++ b/src/hooks/useMessages.ts
@@ -0,0 +1,54 @@
+import { useRef, useEffect, useState, useCallback } from 'react'
+
+type Status = 'submitted' | 'streaming' | 'ready' | 'error'
+
+interface UseMessagesOptions {
+  status: Status
+}
+
+export function useMessages({ status }: UseMessagesOptions) {
+  const [hasSentMessage, setHasSentMessage] = useState(false)
+  const [isAtBottom, setIsAtBottom] = useState(true)
+  
+  const messagesContainerRef = useRef<HTMLDivElement>(null)
+  const messagesEndRef = useRef<HTMLDivElement>(null)
+
+  useEffect(() => {
+    if (status === 'submitted' || status === 'streaming') {
+      setHasSentMessage(true)
+    }
+  }, [status])
+
+  useEffect(() => {
+    const container = messagesContainerRef.current
+    if (!container) return
+
+    const handleScroll = () => {
+      const { scrollTop, scrollHeight, clientHeight } = container
+      const distanceFromBottom = scrollHeight - scrollTop - clientHeight
+      setIsAtBottom(distanceFromBottom <= 100)
+    }
+
+    handleScroll()
+    container.addEventListener('scroll', handleScroll)
+    return () => container.removeEventListener('scroll', handleScroll)
+  }, [])
+
+  const scrollToBottom = useCallback((behavior: 'smooth' | 'auto' = 'smooth') => {
+    messagesEndRef.current?.scrollIntoView({ behavior })
+  }, [])
+
+  useEffect(() => {
+    if (status === 'ready' || status === 'submitted') {
+      scrollToBottom('auto')
+    }
+  }, [status, scrollToBottom])
+
+  return {
+    containerRef: messagesContainerRef,
+    endRef: messagesEndRef,
+    isAtBottom,
+    scrollToBottom,
+    hasSentMessage,
+  }
+}
\ No newline at end of file
diff --git a/src/lib/utils/cn.ts b/src/lib/utils/cn.ts
new file mode 100644
index 0000000..312ce6a
--- /dev/null
+++ b/src/lib/utils/cn.ts
@@ -0,0 +1,6 @@
+import { type ClassValue, clsx } from 'clsx'
+import { twMerge } from 'tailwind-merge'
+
+export function cn(...inputs: ClassValue[]) {
+  return twMerge(clsx(inputs))
+}
\ No newline at end of file
diff --git a/src/lib/utils/index.ts b/src/lib/utils/index.ts
index d9df640..c60f762 100644
--- a/src/lib/utils/index.ts
+++ b/src/lib/utils/index.ts
@@ -3,3 +3,5 @@ export { resolveImagePath } from './images'
 export { stripMarkdown, generateHeadingId, extractLocalImagePathsFromMarkdown } from './markdown'
 export type { TOCItem } from './markdown'
 export { generatePrintHtml } from './print'
+export { cn } from './cn'
+export { generateUUID } from './uuid'
diff --git a/src/lib/utils/uuid.ts b/src/lib/utils/uuid.ts
new file mode 100644
index 0000000..7f2be25
--- /dev/null
+++ b/src/lib/utils/uuid.ts
@@ -0,0 +1,7 @@
+export function generateUUID(): string {
+  return 'xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx'.replace(/[xy]/g, function (c) {
+    const r = (Math.random() * 16) | 0
+    const v = c === 'x' ? r : (r & 0x3) | 0x8
+    return v.toString(16)
+  })
+}
\ No newline at end of file
diff --git a/src/modules/home/HomePage.tsx b/src/modules/home/HomePage.tsx
index d25e3e1..3c61532 100644
--- a/src/modules/home/HomePage.tsx
+++ b/src/modules/home/HomePage.tsx
@@ -1,7 +1,42 @@
-import React from 'react'
+import React, { useState, useEffect } from 'react'
+import { Chat } from '@/components/chat/Chat'
+
+const OPENCODE_API = '/api/opencode'
 
 export const HomePage = () => {
+  const [sessionId, setSessionId] = useState<string | null>(null)
+
+  const createNewSession = async () => {
+    try {
+      const res = await fetch(OPENCODE_API, {
+        method: 'POST',
+        headers: { 'Content-Type': 'application/json' },
+        body: JSON.stringify({ action: 'create-session', title: 'New Chat' }),
+      })
+      const data = await res.json()
+      if (data.session?.id) {
+        setSessionId(data.session.id)
+      }
+    } catch (e) {
+      console.error('Failed to create session:', e)
+    }
+  }
+
+  useEffect(() => {
+    createNewSession()
+  }, [])
+
+  if (!sessionId) {
+    return (
+      <div className="h-full w-full flex items-center justify-center">
+        <div className="text-muted-foreground">Loading...</div>
+      </div>
+    )
+  }
+
   return (
-    <div className="h-full w-full" />
+    <div className="h-full w-full">
+      <Chat key={sessionId} id={sessionId} initialMessages={[]} onClear={createNewSession} />
+    </div>
   )
 }