diff --git a/web/src/chat/presentation.ts b/web/src/chat/presentation.ts
new file mode 100644
index 00000000..2acebf26
--- /dev/null
+++ b/web/src/chat/presentation.ts
@@ -0,0 +1,37 @@
+import type { AgentEvent } from '@/chat/types'
+
+export function formatUnixTimestamp(value: number): string {
+    const ms = value < 1_000_000_000_000 ? value * 1000 : value
+    const date = new Date(ms)
+    if (Number.isNaN(date.getTime())) return String(value)
+    return date.toLocaleString()
+}
+
+export function renderEventLabel(event: AgentEvent): string {
+    if (event.type === 'switch') {
+        const mode = event.mode === 'local' ? 'local' : 'remote'
+        return `🔄 Switched to ${mode}`
+    }
+    if (event.type === 'title-changed') {
+        const title = typeof event.title === 'string' ? event.title : ''
+        return title ? `Title changed to "${title}"` : 'Title changed'
+    }
+    if (event.type === 'permission-mode-changed') {
+        const modeValue = (event as Record<string, unknown>).mode
+        const mode = typeof modeValue === 'string' ? modeValue : 'default'
+        return `🔐 Permission mode: ${mode}`
+    }
+    if (event.type === 'limit-reached') {
+        const endsAt = typeof event.endsAt === 'number' ? event.endsAt : null
+        return endsAt ? `⏳ Usage limit reached until ${formatUnixTimestamp(endsAt)}` : '⏳ Usage limit reached'
+    }
+    if (event.type === 'message') {
+        return typeof event.message === 'string' ? event.message : 'Message'
+    }
+    try {
+        return JSON.stringify(event)
+    } catch {
+        return String(event.type)
+    }
+}
+
diff --git a/web/src/components/AssistantChat/messages/MessageStatusIndicator.tsx b/web/src/components/AssistantChat/messages/MessageStatusIndicator.tsx
new file mode 100644
index 00000000..d20f2529
--- /dev/null
+++ b/web/src/components/AssistantChat/messages/MessageStatusIndicator.tsx
@@ -0,0 +1,38 @@
+import type { MessageStatus } from '@/types/api'
+
+function ErrorIcon() {
+    return (
+        <svg className="h-[14px] w-[14px]" viewBox="0 0 16 16" fill="none">
+            <circle cx="8" cy="8" r="6" stroke="currentColor" strokeWidth="1.5" />
+            <path d="M8 5v4" stroke="currentColor" strokeWidth="1.5" strokeLinecap="round" />
+            <circle cx="8" cy="11" r="0.75" fill="currentColor" />
+        </svg>
+    )
+}
+
+export function MessageStatusIndicator(props: {
+    status?: MessageStatus
+    onRetry?: () => void
+}) {
+    if (props.status !== 'failed') {
+        return null
+    }
+
+    return (
+        <span className="inline-flex items-center gap-1">
+            <span className="text-red-500">
+                <ErrorIcon />
+            </span>
+            {props.onRetry ? (
+                <button
+                    type="button"
+                    onClick={props.onRetry}
+                    className="text-xs text-blue-500 hover:underline"
+                >
+                    重试
+                </button>
+            ) : null}
+        </span>
+    )
+}
+
diff --git a/web/src/components/AssistantChat/messages/ToolMessage.tsx b/web/src/components/AssistantChat/messages/ToolMessage.tsx
index 24b3b11d..19aec2e3 100644
--- a/web/src/components/AssistantChat/messages/ToolMessage.tsx
+++ b/web/src/components/AssistantChat/messages/ToolMessage.tsx
@@ -1,10 +1,11 @@
 import type { ToolCallMessagePartProps } from '@assistant-ui/react'
 import type { ChatBlock } from '@/chat/types'
-import type { AgentEvent, ToolCallBlock } from '@/chat/types'
-import type { MessageStatus } from '@/types/api'
+import type { ToolCallBlock } from '@/chat/types'
+import { renderEventLabel } from '@/chat/presentation'
 import { CodeBlock } from '@/components/CodeBlock'
 import { MarkdownRenderer } from '@/components/MarkdownRenderer'
 import { LazyRainbowText } from '@/components/LazyRainbowText'
+import { MessageStatusIndicator } from '@/components/AssistantChat/messages/MessageStatusIndicator'
 import { ToolCard } from '@/components/ToolCard/ToolCard'
 import { useHappyChatContext } from '@/components/AssistantChat/context'
 
@@ -37,77 +38,6 @@ function isToolCallBlock(value: unknown): value is ToolCallBlock {
     return true
 }
 
-function ErrorIcon() {
-    return (
-        <svg className="h-[14px] w-[14px]" viewBox="0 0 16 16" fill="none">
-            <circle cx="8" cy="8" r="6" stroke="currentColor" strokeWidth="1.5" />
-            <path d="M8 5v4" stroke="currentColor" strokeWidth="1.5" strokeLinecap="round" />
-            <circle cx="8" cy="11" r="0.75" fill="currentColor" />
-        </svg>
-    )
-}
-
-function MessageStatusIndicator(props: {
-    status?: MessageStatus
-    onRetry?: () => void
-}) {
-    if (props.status !== 'failed') {
-        return null
-    }
-
-    return (
-        <span className="inline-flex items-center gap-1">
-            <span className="text-red-500">
-                <ErrorIcon />
-            </span>
-            {props.onRetry ? (
-                <button
-                    type="button"
-                    onClick={props.onRetry}
-                    className="text-xs text-blue-500 hover:underline"
-                >
-                    重试
-                </button>
-            ) : null}
-        </span>
-    )
-}
-
-function formatUnixTimestamp(value: number): string {
-    const ms = value < 1_000_000_000_000 ? value * 1000 : value
-    const date = new Date(ms)
-    if (Number.isNaN(date.getTime())) return String(value)
-    return date.toLocaleString()
-}
-
-function renderEventLabel(event: AgentEvent): string {
-    if (event.type === 'switch') {
-        const mode = event.mode === 'local' ? 'local' : 'remote'
-        return `🔄 Switched to ${mode}`
-    }
-    if (event.type === 'title-changed') {
-        const title = typeof event.title === 'string' ? event.title : ''
-        return title ? `Title changed to "${title}"` : 'Title changed'
-    }
-    if (event.type === 'permission-mode-changed') {
-        const modeValue = (event as Record<string, unknown>).mode
-        const mode = typeof modeValue === 'string' ? modeValue : 'default'
-        return `🔐 Permission mode: ${mode}`
-    }
-    if (event.type === 'limit-reached') {
-        const endsAt = typeof event.endsAt === 'number' ? event.endsAt : null
-        return endsAt ? `⏳ Usage limit reached until ${formatUnixTimestamp(endsAt)}` : '⏳ Usage limit reached'
-    }
-    if (event.type === 'message') {
-        return typeof event.message === 'string' ? event.message : 'Message'
-    }
-    try {
-        return JSON.stringify(event)
-    } catch {
-        return String(event.type)
-    }
-}
-
 function HappyNestedBlockList(props: {
     blocks: ChatBlock[]
 }) {
diff --git a/web/src/components/AssistantChat/messages/UserMessage.tsx b/web/src/components/AssistantChat/messages/UserMessage.tsx
index d3e8d284..046a7e92 100644
--- a/web/src/components/AssistantChat/messages/UserMessage.tsx
+++ b/web/src/components/AssistantChat/messages/UserMessage.tsx
@@ -1,44 +1,8 @@
 import { MessagePrimitive, useAssistantState } from '@assistant-ui/react'
-import type { MessageStatus } from '@/types/api'
 import { LazyRainbowText } from '@/components/LazyRainbowText'
 import { useHappyChatContext } from '@/components/AssistantChat/context'
 import type { HappyChatMessageMetadata } from '@/lib/assistant-runtime'
-
-function ErrorIcon() {
-    return (
-        <svg className="h-[14px] w-[14px]" viewBox="0 0 16 16" fill="none">
-            <circle cx="8" cy="8" r="6" stroke="currentColor" strokeWidth="1.5" />
-            <path d="M8 5v4" stroke="currentColor" strokeWidth="1.5" strokeLinecap="round" />
-            <circle cx="8" cy="11" r="0.75" fill="currentColor" />
-        </svg>
-    )
-}
-
-function MessageStatusIndicator(props: {
-    status?: MessageStatus
-    onRetry?: () => void
-}) {
-    if (props.status !== 'failed') {
-        return null
-    }
-
-    return (
-        <span className="inline-flex items-center gap-1">
-            <span className="text-red-500">
-                <ErrorIcon />
-            </span>
-            {props.onRetry ? (
-                <button
-                    type="button"
-                    onClick={props.onRetry}
-                    className="text-xs text-blue-500 hover:underline"
-                >
-                    重试
-                </button>
-            ) : null}
-        </span>
-    )
-}
+import { MessageStatusIndicator } from '@/components/AssistantChat/messages/MessageStatusIndicator'
 
 export function HappyUserMessage() {
     const ctx = useHappyChatContext()
@@ -70,4 +34,3 @@ export function HappyUserMessage() {
         </MessagePrimitive.Root>
     )
 }
-
diff --git a/web/src/lib/assistant-runtime.ts b/web/src/lib/assistant-runtime.ts
index 02617a2b..8f164e0e 100644
--- a/web/src/lib/assistant-runtime.ts
+++ b/web/src/lib/assistant-runtime.ts
@@ -1,6 +1,7 @@
 import { useMemo } from 'react'
 import type { AppendMessage, ExternalStoreAdapter, ThreadMessageLike } from '@assistant-ui/react'
 import { useExternalStoreRuntime } from '@assistant-ui/react'
+import { renderEventLabel } from '@/chat/presentation'
 import type { ChatBlock } from '@/chat/types'
 import type { AgentEvent, ToolCallBlock } from '@/chat/types'
 import type { MessageStatus as HappyMessageStatus, Session } from '@/types/api'
@@ -15,41 +16,6 @@ function safeStringify(value: unknown): string {
     }
 }
 
-function formatUnixTimestamp(value: number): string {
-    const ms = value < 1_000_000_000_000 ? value * 1000 : value
-    const date = new Date(ms)
-    if (Number.isNaN(date.getTime())) return String(value)
-    return date.toLocaleString()
-}
-
-function renderEventLabel(event: AgentEvent): string {
-    if (event.type === 'switch') {
-        const mode = event.mode === 'local' ? 'local' : 'remote'
-        return `🔄 Switched to ${mode}`
-    }
-    if (event.type === 'title-changed') {
-        const title = typeof event.title === 'string' ? event.title : ''
-        return title ? `Title changed to "${title}"` : 'Title changed'
-    }
-    if (event.type === 'permission-mode-changed') {
-        const modeValue = (event as Record<string, unknown>).mode
-        const mode = typeof modeValue === 'string' ? modeValue : 'default'
-        return `🔐 Permission mode: ${mode}`
-    }
-    if (event.type === 'limit-reached') {
-        const endsAt = typeof event.endsAt === 'number' ? event.endsAt : null
-        return endsAt ? `⏳ Usage limit reached until ${formatUnixTimestamp(endsAt)}` : '⏳ Usage limit reached'
-    }
-    if (event.type === 'message') {
-        return typeof event.message === 'string' ? event.message : 'Message'
-    }
-    try {
-        return JSON.stringify(event)
-    } catch {
-        return String(event.type)
-    }
-}
-
 export type HappyChatMessageMetadata = {
     kind: 'user' | 'assistant' | 'tool' | 'event'
     status?: HappyMessageStatus