diff --git a/desktop/src/components/chat/AttachmentGallery.tsx b/desktop/src/components/chat/AttachmentGallery.tsx
index 484dfda4..2d83e685 100644
--- a/desktop/src/components/chat/AttachmentGallery.tsx
+++ b/desktop/src/components/chat/AttachmentGallery.tsx
@@ -5,8 +5,13 @@ export type AttachmentPreview = {
   id?: string
   type: 'image' | 'file'
   name: string
+  path?: string
   data?: string
   previewUrl?: string
+  lineStart?: number
+  lineEnd?: number
+  note?: string
+  quote?: string
 }
 
 type Props = {
@@ -35,7 +40,7 @@ export function AttachmentGallery({ attachments, variant = 'message', onRemove }
 
   return (
     <>
-      <div className={isComposer ? 'flex flex-wrap items-center gap-2' : 'grid grid-cols-1 gap-2 sm:grid-cols-2'}>
+      <div className={isComposer ? 'flex flex-wrap items-center gap-2' : 'flex flex-wrap justify-end gap-2'}>
         {attachments.map((attachment, index) => {
           if (attachment.type === 'image' && (attachment.previewUrl || attachment.data)) {
             const src = attachment.previewUrl || attachment.data || ''
@@ -80,18 +85,29 @@ export function AttachmentGallery({ attachments, variant = 'message', onRemove }
           return (
             <div
               key={attachment.id || `${attachment.name}-${index}`}
-              className="flex items-center gap-2 rounded-xl border border-[var(--color-border)] bg-[var(--color-surface-container-low)] px-3 py-2 text-xs text-[var(--color-text-secondary)]"
+              className={[
+                'group/file inline-flex max-w-full min-w-0 items-center gap-2 rounded-full border border-[var(--color-border)]',
+                'bg-[var(--color-surface-container-low)] text-[var(--color-text-secondary)] shadow-[0_1px_2px_rgba(0,0,0,0.04)]',
+                isComposer ? 'h-9 px-3' : 'h-9 px-3',
+              ].join(' ')}
             >
-              <span className="material-symbols-outlined text-[14px]">attach_file</span>
-              <span className="max-w-[220px] truncate">{attachment.name}</span>
+              <span className="material-symbols-outlined shrink-0 text-[17px] text-[var(--color-text-tertiary)]">
+                {attachment.lineStart ? 'chat_bubble' : 'description'}
+              </span>
+              <span className="min-w-0 max-w-[220px] truncate text-[13px] font-medium leading-none text-[var(--color-text-primary)]">
+                {attachment.name}
+                {attachment.lineStart
+                  ? `:L${attachment.lineStart}${attachment.lineEnd && attachment.lineEnd !== attachment.lineStart ? `-L${attachment.lineEnd}` : ''}`
+                  : ''}
+              </span>
               {onRemove && attachment.id && (
                 <button
                   type="button"
                   onClick={() => onRemove(attachment.id!)}
-                  className="ml-1 text-[var(--color-text-tertiary)] transition-colors hover:text-[var(--color-error)]"
+                  className="ml-0.5 flex h-5 w-5 shrink-0 items-center justify-center rounded-full text-[var(--color-text-tertiary)] transition-colors hover:text-[var(--color-text-primary)]"
                   aria-label={`Remove ${attachment.name}`}
                 >
-                  <span className="material-symbols-outlined text-[14px]">close</span>
+                  <span className="material-symbols-outlined text-[17px]">close</span>
                 </button>
               )}
             </div>
diff --git a/desktop/src/components/chat/ChatInput.tsx b/desktop/src/components/chat/ChatInput.tsx
index 5b9a3afe..ad884be1 100644
--- a/desktop/src/components/chat/ChatInput.tsx
+++ b/desktop/src/components/chat/ChatInput.tsx
@@ -6,6 +6,11 @@ import { useUIStore } from '../../stores/uiStore'
 import { useSessionStore } from '../../stores/sessionStore'
 import { useSessionRuntimeStore } from '../../stores/sessionRuntimeStore'
 import { useTeamStore } from '../../stores/teamStore'
+import {
+  formatWorkspaceReferencePrompt,
+  useWorkspaceChatContextStore,
+  type WorkspaceChatReference,
+} from '../../stores/workspaceChatContextStore'
 import { sessionsApi } from '../../api/sessions'
 import { PermissionModeSelector } from '../controls/PermissionModeSelector'
 import { ModelSelector } from '../controls/ModelSelector'
@@ -29,9 +34,14 @@ type Attachment = {
   id: string
   name: string
   type: 'image' | 'file'
+  path?: string
   mimeType?: string
   previewUrl?: string
   data?: string
+  lineStart?: number
+  lineEnd?: number
+  note?: string
+  quote?: string
 }
 
 type ChatInputProps = {
@@ -39,6 +49,21 @@ type ChatInputProps = {
   compact?: boolean
 }
 
+const EMPTY_WORKSPACE_REFERENCES: WorkspaceChatReference[] = []
+
+function workspaceReferenceToAttachment(reference: WorkspaceChatReference): Attachment {
+  return {
+    id: reference.id,
+    name: reference.name,
+    type: 'file',
+    path: reference.path,
+    lineStart: reference.lineStart,
+    lineEnd: reference.lineEnd,
+    note: reference.note,
+    quote: reference.quote,
+  }
+}
+
 export function ChatInput({ variant = 'default', compact = false }: ChatInputProps) {
   const t = useTranslation()
   const [input, setInput] = useState('')
@@ -68,13 +93,27 @@ export function ChatInput({ variant = 'default', compact = false }: ChatInputPro
   const memberInfo = useTeamStore((s) => activeTabId ? s.getMemberBySessionId(activeTabId) : null)
   const [gitInfo, setGitInfo] = useState<GitInfo | null>(null)
   const hasMessages = useChatStore((s) => activeTabId ? (s.sessions[activeTabId]?.messages?.length ?? 0) > 0 : false)
+  const workspaceReferences = useWorkspaceChatContextStore(
+    (s) => activeTabId ? s.referencesBySession[activeTabId] ?? EMPTY_WORKSPACE_REFERENCES : EMPTY_WORKSPACE_REFERENCES,
+  )
+  const addWorkspaceReference = useWorkspaceChatContextStore((s) => s.addReference)
+  const removeWorkspaceReference = useWorkspaceChatContextStore((s) => s.removeReference)
+  const clearWorkspaceReferences = useWorkspaceChatContextStore((s) => s.clearReferences)
 
   const isMemberSession = !!memberInfo
   const isActive = chatState !== 'idle'
   const isWorkspaceMissing = activeSession?.workDirExists === false
-  const canSubmit = !isWorkspaceMissing && (input.trim().length > 0 || (!isMemberSession && attachments.length > 0))
+  const hasWorkspaceReferences = !isMemberSession && workspaceReferences.length > 0
+  const canSubmit = !isWorkspaceMissing && (input.trim().length > 0 || (!isMemberSession && (attachments.length > 0 || hasWorkspaceReferences)))
   const isHeroComposer = variant === 'hero' && !isMemberSession && !compact
   const resolvedWorkDir = activeSession?.workDir || gitInfo?.workDir || undefined
+  const composerAttachments = useMemo(
+    () => [
+      ...attachments,
+      ...workspaceReferences.map(workspaceReferenceToAttachment),
+    ],
+    [attachments, workspaceReferences],
+  )
 
   useEffect(() => {
     textareaRef.current?.focus()
@@ -303,7 +342,7 @@ export function ChatInput({ variant = 'default', compact = false }: ChatInputPro
 
   const handleSubmit = () => {
     const text = input.trim()
-    if ((!text && (!attachments.length || isMemberSession)) || isWorkspaceMissing) return
+    if ((!text && ((!attachments.length && !hasWorkspaceReferences) || isMemberSession)) || isWorkspaceMissing) return
 
     const slashUiAction = !isMemberSession && text.startsWith('/') ? resolveSlashUiAction(text.slice(1)) : null
     if (slashUiAction?.type === 'panel') {
@@ -325,16 +364,55 @@ export function ChatInput({ variant = 'default', compact = false }: ChatInputPro
       return
     }
 
-    const attachmentPayload: AttachmentRef[] = attachments.map((attachment) => ({
+    const workspaceReferencePrompt = !isMemberSession
+      ? formatWorkspaceReferencePrompt(workspaceReferences)
+      : ''
+    const contentForModel = [workspaceReferencePrompt, text].filter(Boolean).join('\n\n')
+    const displayContent = text || (
+      workspaceReferences.length > 0
+        ? t('chat.workspaceReferencesOnly', { count: workspaceReferences.length })
+        : ''
+    )
+    const uploadAttachmentPayload: AttachmentRef[] = attachments.map((attachment) => ({
       type: attachment.type,
       name: attachment.name,
+      path: attachment.path,
       data: attachment.data,
       mimeType: attachment.mimeType,
+      lineStart: attachment.lineStart,
+      lineEnd: attachment.lineEnd,
+      note: attachment.note,
+      quote: attachment.quote,
     }))
+    const workspaceAttachmentPayload: AttachmentRef[] = workspaceReferences.map((reference) => ({
+      type: 'file' as const,
+      name: reference.name,
+      path: reference.absolutePath ?? reference.path,
+      lineStart: reference.lineStart,
+      lineEnd: reference.lineEnd,
+      note: reference.note,
+      quote: reference.quote,
+    }))
+    const visibleAttachmentPayload: AttachmentRef[] = [
+      ...uploadAttachmentPayload,
+      ...workspaceReferences.map((reference) => ({
+        type: 'file' as const,
+        name: reference.name,
+        path: reference.path,
+        lineStart: reference.lineStart,
+        lineEnd: reference.lineEnd,
+        note: reference.note,
+        quote: reference.quote,
+      })),
+    ]
 
-    sendMessage(activeTabId!, text, attachmentPayload)
+    sendMessage(activeTabId!, contentForModel, [...uploadAttachmentPayload, ...workspaceAttachmentPayload], {
+      displayContent,
+      displayAttachments: visibleAttachmentPayload,
+    })
     setInput('')
     setAttachments([])
+    if (!isMemberSession) clearWorkspaceReferences(activeTabId!)
     setPlusMenuOpen(false)
     setSlashMenuOpen(false)
     setFileSearchOpen(false)
@@ -488,6 +566,7 @@ export function ChatInput({ variant = 'default', compact = false }: ChatInputPro
 
   const removeAttachment = (id: string) => {
     setAttachments((prev) => prev.filter((attachment) => attachment.id !== id))
+    if (activeTabId) removeWorkspaceReference(activeTabId, id)
   }
 
   const insertSlashCommand = () => {
@@ -550,11 +629,19 @@ export function ChatInput({ variant = 'default', compact = false }: ChatInputPro
               ref={fileSearchRef}
               cwd={resolvedWorkDir || ''}
               filter={atFilter}
-              onSelect={(_path, name) => {
+              onSelect={(path, name) => {
                 if (atCursorPos >= 0) {
                   // Insert name at cursor position, replacing filter text
                   const newValue = `${input.slice(0, atCursorPos)}${name}${input.slice(atCursorPos)}`
                   const newCursorPos = atCursorPos + name.length
+                  if (activeTabId) {
+                    addWorkspaceReference(activeTabId, {
+                      kind: 'file',
+                      path,
+                      absolutePath: path,
+                      name,
+                    })
+                  }
                   setInput(newValue)
                   setFileSearchOpen(false)
                   setAtFilter('')
@@ -618,12 +705,12 @@ export function ChatInput({ variant = 'default', compact = false }: ChatInputPro
             </div>
           )}
 
-          {attachments.length > 0 && (
+          {composerAttachments.length > 0 && (
             isHeroComposer ? (
-              <AttachmentGallery attachments={attachments} variant="composer" onRemove={removeAttachment} />
+              <AttachmentGallery attachments={composerAttachments} variant="composer" onRemove={removeAttachment} />
             ) : (
               <div className="px-3 pt-3">
-                <AttachmentGallery attachments={attachments} variant="composer" onRemove={removeAttachment} />
+                <AttachmentGallery attachments={composerAttachments} variant="composer" onRemove={removeAttachment} />
               </div>
             )
           )}
diff --git a/desktop/src/components/chat/MessageList.test.tsx b/desktop/src/components/chat/MessageList.test.tsx
index c24749d2..d0966d77 100644
--- a/desktop/src/components/chat/MessageList.test.tsx
+++ b/desktop/src/components/chat/MessageList.test.tsx
@@ -662,6 +662,7 @@ describe('MessageList nested tool calls', () => {
               id: 'user-2',
               type: 'user_text',
               content: '第二段',
+              modelContent: '@"/tmp/example-project/src/App.tsx" 第二段',
               timestamp: 3,
             },
             {
@@ -686,7 +687,7 @@ describe('MessageList nested tool calls', () => {
     expect(sessionsApi.rewind).toHaveBeenCalledWith(ACTIVE_TAB, {
       targetUserMessageId: 'user-2',
       userMessageIndex: 1,
-      expectedContent: '第二段',
+      expectedContent: '@"/tmp/example-project/src/App.tsx" 第二段',
       dryRun: true,
     })
   })
diff --git a/desktop/src/components/chat/MessageList.tsx b/desktop/src/components/chat/MessageList.tsx
index f299a782..8fd854c0 100644
--- a/desktop/src/components/chat/MessageList.tsx
+++ b/desktop/src/components/chat/MessageList.tsx
@@ -38,6 +38,7 @@ type RewindTurnTarget = {
   messageId: string
   userMessageIndex: number
   content: string
+  expectedContent: string
   attachments?: Extract<UIMessage, { type: 'user_text' }>['attachments']
 }
 
@@ -129,6 +130,7 @@ export function getLatestCompletedTurnTarget(messages: UIMessage[]): RewindTurnT
       messageId: message.id,
       userMessageIndex,
       content: message.content,
+      expectedContent: message.modelContent ?? message.content,
       attachments: message.attachments,
       messageOffset,
     }
@@ -240,7 +242,7 @@ export function MessageList({ sessionId, compact = false }: MessageListProps = {
       sessionsApi.rewind(resolvedSessionId, {
         targetUserMessageId: latestTurnTarget.messageId,
         userMessageIndex: latestTurnTarget.userMessageIndex,
-        expectedContent: latestTurnTarget.content,
+        expectedContent: latestTurnTarget.expectedContent,
         dryRun: true,
       }),
       sessionsApi.getWorkspaceStatus(resolvedSessionId).catch(() => null),
@@ -295,7 +297,7 @@ export function MessageList({ sessionId, compact = false }: MessageListProps = {
       const result = await sessionsApi.rewind(resolvedSessionId, {
         targetUserMessageId: target.messageId,
         userMessageIndex: target.userMessageIndex,
-        expectedContent: target.content,
+        expectedContent: target.expectedContent,
       })
 
       await reloadHistory(resolvedSessionId)
diff --git a/desktop/src/components/workspace/WorkspacePanel.test.tsx b/desktop/src/components/workspace/WorkspacePanel.test.tsx
index e810c544..5c9e7fe0 100644
--- a/desktop/src/components/workspace/WorkspacePanel.test.tsx
+++ b/desktop/src/components/workspace/WorkspacePanel.test.tsx
@@ -120,22 +120,26 @@ vi.mock('../../api/sessions', () => ({
 }))
 
 import { useSettingsStore } from '../../stores/settingsStore'
+import { useWorkspaceChatContextStore } from '../../stores/workspaceChatContextStore'
 import { useWorkspacePanelStore } from '../../stores/workspacePanelStore'
 import { WorkspacePanel } from './WorkspacePanel'
 
 describe('WorkspacePanel', () => {
   const workspaceInitialState = useWorkspacePanelStore.getInitialState()
+  const workspaceChatInitialState = useWorkspaceChatContextStore.getInitialState()
   const settingsInitialState = useSettingsStore.getInitialState()
 
   beforeEach(async () => {
     vi.clearAllMocks()
     await setWorkspaceState(workspaceInitialState)
+    useWorkspaceChatContextStore.setState(workspaceChatInitialState, true)
     await setSettingsState({ ...settingsInitialState, locale: 'en' })
   })
 
   afterEach(async () => {
     cleanup()
     await setWorkspaceState(workspaceInitialState)
+    useWorkspaceChatContextStore.setState(workspaceChatInitialState, true)
     await setSettingsState(settingsInitialState)
     vi.restoreAllMocks()
   })
@@ -792,6 +796,123 @@ describe('WorkspacePanel', () => {
     expect(view.queryByRole('tab', { name: /index\.css/i })).toBeNull()
   })
 
+  it('adds a workspace file to the chat context from the file tree menu', async () => {
+    await setWorkspaceState((state) => ({
+      ...state,
+      panelBySession: {
+        ...state.panelBySession,
+        'session-add-file': {
+          isOpen: true,
+          activeView: 'all',
+        },
+      },
+      statusBySession: {
+        ...state.statusBySession,
+        'session-add-file': {
+          state: 'ok',
+          workDir: '/repo',
+          repoName: 'repo',
+          branch: 'main',
+          isGitRepo: true,
+          changedFiles: [],
+        },
+      },
+      treeBySessionPath: {
+        ...state.treeBySessionPath,
+        'session-add-file': {
+          '': {
+            state: 'ok',
+            path: '',
+            entries: [{ name: 'App.tsx', path: 'src/App.tsx', isDirectory: false }],
+          },
+        },
+      },
+    }))
+
+    const view = await renderPanel('session-add-file')
+
+    await act(() => {
+      fireEvent.contextMenu(view.getByRole('button', { name: /App\.tsx/i }), {
+        clientX: 260,
+        clientY: 80,
+      })
+    })
+
+    await clickElement(view.getByRole('menuitem', { name: 'Add to chat' }))
+
+    expect(useWorkspaceChatContextStore.getState().referencesBySession['session-add-file']).toMatchObject([
+      {
+        kind: 'file',
+        path: 'src/App.tsx',
+        absolutePath: '/repo/src/App.tsx',
+        name: 'App.tsx',
+      },
+    ])
+  })
+
+  it('adds a line comment from a code preview to the chat context', async () => {
+    await setWorkspaceState((state) => ({
+      ...state,
+      panelBySession: {
+        ...state.panelBySession,
+        'session-line-comment': {
+          isOpen: true,
+          activeView: 'all',
+        },
+      },
+      statusBySession: {
+        ...state.statusBySession,
+        'session-line-comment': {
+          state: 'ok',
+          workDir: '/repo',
+          repoName: 'repo',
+          branch: 'main',
+          isGitRepo: true,
+          changedFiles: [],
+        },
+      },
+      previewTabsBySession: {
+        ...state.previewTabsBySession,
+        'session-line-comment': [{
+          id: 'file:src/App.tsx',
+          path: 'src/App.tsx',
+          kind: 'file',
+          title: 'App.tsx',
+          language: 'tsx',
+          content: 'const title = "Todo"\nexport default title',
+          state: 'ok',
+          size: 42,
+        }],
+      },
+      activePreviewTabIdBySession: {
+        ...state.activePreviewTabIdBySession,
+        'session-line-comment': 'file:src/App.tsx',
+      },
+    }))
+
+    const view = await renderPanel('session-line-comment')
+
+    await clickElement(view.getByRole('button', { name: 'Comment line 1' }))
+    const textarea = view.getByPlaceholderText('Describe what should change here...')
+    await act(() => {
+      fireEvent.change(textarea, { target: { value: 'Rename this title' } })
+    })
+    await clickElement(view.getByRole('button', { name: 'Add comment' }))
+
+    expect(useWorkspaceChatContextStore.getState().referencesBySession['session-line-comment']).toMatchObject([
+      {
+        kind: 'code-comment',
+        path: 'src/App.tsx',
+        absolutePath: '/repo/src/App.tsx',
+        name: 'App.tsx',
+        lineStart: 1,
+        lineEnd: 1,
+        note: 'Rename this title',
+        quote: 'const title = "Todo"',
+      },
+    ])
+  })
+
   it('uses the localized view menu label', async () => {
     await setSettingsState({ ...settingsInitialState, locale: 'zh' })
     await setWorkspaceState((state) => ({
diff --git a/desktop/src/components/workspace/WorkspacePanel.tsx b/desktop/src/components/workspace/WorkspacePanel.tsx
index 76fad69d..b65830ba 100644
--- a/desktop/src/components/workspace/WorkspacePanel.tsx
+++ b/desktop/src/components/workspace/WorkspacePanel.tsx
@@ -14,6 +14,7 @@ import {
   type WorkspacePreviewKind,
   type WorkspacePreviewTab,
 } from '../../stores/workspacePanelStore'
+import { useWorkspaceChatContextStore } from '../../stores/workspaceChatContextStore'
 import { MarkdownRenderer } from '../markdown/MarkdownRenderer'
 import {
   getFileExtension,
@@ -38,6 +39,7 @@ type TreeNodeProps = {
   filterQuery: string
   onToggle: (path: string) => void
   onOpenFile: (path: string) => void
+  onFileContextMenu: (event: MouseEvent, path: string) => void
   activePath: string | null
 }
 
@@ -128,6 +130,11 @@ function getFileBadgeMeta(name: string) {
   }
 }
 
+function resolveWorkspaceAttachmentPath(workDir: string | undefined, filePath: string) {
+  if (!workDir || filePath.startsWith('/') || /^[a-zA-Z]:[\\/]/.test(filePath)) return filePath
+  return `${workDir.replace(/[\\/]+$/, '')}/${filePath.replace(/^[/\\]+/, '')}`
+}
+
 function isMarkdownPreview(tab: WorkspacePreviewTab) {
   if (tab.kind !== 'file') return false
   const language = (tab.language ?? '').toLowerCase()
@@ -296,12 +303,30 @@ function FileStatusBadge({ status }: { status: WorkspaceFileStatus }) {
   )
 }
 
-function CodeSurface({ value, language }: { value: string; language: string }) {
+function CodeSurface({
+  value,
+  language,
+  onAddLineComment,
+}: {
+  value: string
+  language: string
+  onAddLineComment: (line: number, note: string, quote: string) => void
+}) {
   const t = useTranslation()
+  const [commentLine, setCommentLine] = useState<number | null>(null)
+  const [commentDraft, setCommentDraft] = useState('')
   const lines = value.split('\n')
   const visibleLines = lines.slice(0, WORKSPACE_PREVIEW_LINE_LIMIT)
   const visibleCode = visibleLines.join('\n')
   const hiddenLineCount = Math.max(0, lines.length - visibleLines.length)
+  const activeQuote = commentLine ? visibleLines[commentLine - 1] ?? '' : ''
+
+  const submitLineComment = () => {
+    if (!commentLine || !commentDraft.trim()) return
+    onAddLineComment(commentLine, commentDraft.trim(), activeQuote)
+    setCommentLine(null)
+    setCommentDraft('')
+  }
 
   return (
     <div className="min-h-0 flex-1 overflow-auto bg-[var(--color-code-bg)]">
@@ -320,21 +345,73 @@ function CodeSurface({ value, language }: { value: string; language: string }) {
             >
               {tokens.map((line, index) => {
                 const { key: lineKey, ...lineProps } = getLineProps({ line, key: index })
+                const lineNumber = index + 1
                 return (
-                  <div
-                    key={String(lineKey)}
-                    {...lineProps}
-                    className="grid grid-cols-[48px_minmax(0,1fr)] gap-3 px-3 hover:bg-[var(--color-surface-hover)]"
-                  >
-                    <span className="select-none text-right text-[11px] text-[var(--color-text-tertiary)]">
-                      {index + 1}
-                    </span>
-                    <span className="whitespace-pre pr-6">
-                      {line.length === 1 && line[0]?.empty ? ' ' : line.map((token, tokenIndex) => {
-                        const { key: tokenKey, ...tokenProps } = getTokenProps({ token, key: tokenIndex })
-                        return <span key={String(tokenKey)} {...tokenProps} />
-                      })}
-                    </span>
+                  <div key={String(lineKey)}>
+                    <div
+                      {...lineProps}
+                      className="group grid grid-cols-[48px_minmax(0,1fr)] gap-3 px-3 hover:bg-[var(--color-surface-hover)]"
+                    >
+                      <button
+                        type="button"
+                        aria-label={t('workspace.commentLine', { line: lineNumber })}
+                        onClick={() => {
+                          setCommentLine(lineNumber)
+                          setCommentDraft('')
+                        }}
+                        className="select-none text-right text-[11px] text-[var(--color-text-tertiary)] transition-colors hover:text-[var(--color-brand)] focus-visible:outline-none focus-visible:text-[var(--color-brand)]"
+                      >
+                        {lineNumber}
+                      </button>
+                      <span className="whitespace-pre pr-6">
+                        {line.length === 1 && line[0]?.empty ? ' ' : line.map((token, tokenIndex) => {
+                          const { key: tokenKey, ...tokenProps } = getTokenProps({ token, key: tokenIndex })
+                          return <span key={String(tokenKey)} {...tokenProps} />
+                        })}
+                      </span>
+                    </div>
+                    {commentLine === lineNumber && (
+                      <div className="grid grid-cols-[48px_minmax(0,720px)] gap-3 bg-[var(--color-brand)]/10 px-3 py-2">
+                        <span aria-hidden="true" />
+                        <div className="rounded-[10px] border border-[var(--color-border)] bg-[var(--color-surface-container-lowest)] shadow-sm">
+                          <div className="flex items-center gap-2 border-b border-[var(--color-border)] px-3 py-2">
+                            <span className="material-symbols-outlined text-[15px] text-[var(--color-text-tertiary)]">chat_bubble</span>
+                            <span className="text-[12px] font-semibold text-[var(--color-text-primary)]">{t('workspace.localComment')}</span>
+                            <span className="ml-auto text-[11px] text-[var(--color-text-tertiary)]">
+                              {t('workspace.commentLineTarget', { line: lineNumber })}
+                            </span>
+                          </div>
+                          <textarea
+                            value={commentDraft}
+                            onChange={(event) => setCommentDraft(event.target.value)}
+                            autoFocus
+                            rows={3}
+                            placeholder={t('workspace.commentPlaceholder')}
+                            className="block w-full resize-none bg-transparent px-3 py-3 text-[13px] leading-6 text-[var(--color-text-primary)] outline-none placeholder:text-[var(--color-text-tertiary)]"
+                          />
+                          <div className="flex justify-end gap-2 px-3 pb-3">
+                            <button
+                              type="button"
+                              onClick={() => {
+                                setCommentLine(null)
+                                setCommentDraft('')
+                              }}
+                              className="rounded-[7px] px-2.5 py-1 text-[12px] text-[var(--color-text-secondary)] hover:bg-[var(--color-surface-hover)]"
+                            >
+                              {t('common.cancel')}
+                            </button>
+                            <button
+                              type="button"
+                              onClick={submitLineComment}
+                              disabled={!commentDraft.trim()}
+                              className="rounded-[7px] bg-[var(--color-text-primary)] px-2.5 py-1 text-[12px] font-medium text-[var(--color-surface)] disabled:cursor-not-allowed disabled:opacity-45"
+                            >
+                              {t('workspace.addCommentToChat')}
+                            </button>
+                          </div>
+                        </div>
+                      </div>
+                    )}
                   </div>
                 )
               })}
@@ -393,14 +470,17 @@ function ImagePreview({ tab }: { tab: WorkspacePreviewTab }) {
 function ChangedFileRow({
   file,
   onClick,
+  onContextMenu,
 }: {
   file: WorkspaceChangedFile
   onClick: () => void
+  onContextMenu: (event: MouseEvent, path: string) => void
 }) {
   return (
     <button
       type="button"
       onClick={onClick}
+      onContextMenu={(event) => onContextMenu(event, file.path)}
       className="mx-2 flex w-[calc(100%-16px)] items-center gap-3 rounded-[7px] px-2 py-2 text-left transition-colors hover:bg-[var(--color-surface-hover)]"
     >
       <FileStatusBadge status={file.status} />
@@ -431,6 +511,7 @@ function TreeNode({
   filterQuery,
   onToggle,
   onOpenFile,
+  onFileContextMenu,
   activePath,
 }: TreeNodeProps) {
   const t = useTranslation()
@@ -447,6 +528,7 @@ function TreeNode({
       <button
         type="button"
         onClick={() => onOpenFile(entry.path)}
+        onContextMenu={(event) => onFileContextMenu(event, entry.path)}
         className={`group mx-2 flex h-8 w-[calc(100%-16px)] items-center gap-2 rounded-[7px] pr-2 text-left transition-colors ${
           isActive
             ? 'bg-[var(--color-surface-selected)] shadow-[inset_0_0_0_1.5px_var(--color-border-focus)]'
@@ -528,6 +610,7 @@ function TreeNode({
                 filterQuery={filterQuery}
                 onToggle={onToggle}
                 onOpenFile={onOpenFile}
+                onFileContextMenu={onFileContextMenu}
                 activePath={activePath}
               />
             ))}
@@ -542,6 +625,7 @@ export function WorkspacePanel({ sessionId }: WorkspacePanelProps) {
   const [filterQuery, setFilterQuery] = useState('')
   const [isViewMenuOpen, setIsViewMenuOpen] = useState(false)
   const [previewTabContextMenu, setPreviewTabContextMenu] = useState<{ tabId: string; x: number; y: number } | null>(null)
+  const [fileContextMenu, setFileContextMenu] = useState<{ path: string; x: number; y: number } | null>(null)
   const width = useWorkspacePanelStore((state) => state.width)
   const isOpen = useWorkspacePanelStore((state) => state.isPanelOpen(sessionId))
   const activeView = useWorkspacePanelStore((state) => state.getActiveView(sessionId))
@@ -566,6 +650,7 @@ export function WorkspacePanel({ sessionId }: WorkspacePanelProps) {
   const closePreview = useWorkspacePanelStore((state) => state.closePreview)
   const closePreviewTabs = useWorkspacePanelStore((state) => state.closePreviewTabs)
   const closePanel = useWorkspacePanelStore((state) => state.closePanel)
+  const addWorkspaceReference = useWorkspaceChatContextStore((state) => state.addReference)
 
   const rootTree = treeByPath['']
   const rootTreeKey = makeTreeStateKey(sessionId, '')
@@ -607,11 +692,14 @@ export function WorkspacePanel({ sessionId }: WorkspacePanelProps) {
   }, [activeView, isOpen, loadTree, rootTree, rootTreeError, rootTreeLoading, sessionId])
 
   useEffect(() => {
-    if (!previewTabContextMenu) return
-    const close = () => setPreviewTabContextMenu(null)
+    if (!previewTabContextMenu && !fileContextMenu) return
+    const close = () => {
+      setPreviewTabContextMenu(null)
+      setFileContextMenu(null)
+    }
     document.addEventListener('click', close)
     return () => document.removeEventListener('click', close)
-  }, [previewTabContextMenu])
+  }, [fileContextMenu, previewTabContextMenu])
 
   if (!isOpen) return null
 
@@ -635,6 +723,28 @@ export function WorkspacePanel({ sessionId }: WorkspacePanelProps) {
     void openPreview(sessionId, path, 'file')
   }
 
+  const addFileToChat = (path: string) => {
+    addWorkspaceReference(sessionId, {
+      kind: 'file',
+      path,
+      absolutePath: resolveWorkspaceAttachmentPath(status?.workDir, path),
+      name: path.split('/').pop() || path,
+    })
+  }
+
+  const addLineCommentToChat = (path: string, line: number, note: string, quote: string) => {
+    addWorkspaceReference(sessionId, {
+      kind: 'code-comment',
+      path,
+      absolutePath: resolveWorkspaceAttachmentPath(status?.workDir, path),
+      name: path.split('/').pop() || path,
+      lineStart: line,
+      lineEnd: line,
+      note,
+      quote,
+    })
+  }
+
   const handleSetActiveView = (view: 'changed' | 'all') => {
     setActiveView(sessionId, view)
     setIsViewMenuOpen(false)
@@ -643,15 +753,29 @@ export function WorkspacePanel({ sessionId }: WorkspacePanelProps) {
   const handlePreviewTabContextMenu = (event: MouseEvent, tabId: string) => {
     event.preventDefault()
     event.stopPropagation()
+    setFileContextMenu(null)
     setPreviewTabContextMenu({ tabId, x: event.clientX, y: event.clientY })
   }
 
+  const handleFileContextMenu = (event: MouseEvent, path: string) => {
+    event.preventDefault()
+    event.stopPropagation()
+    setPreviewTabContextMenu(null)
+    setFileContextMenu({ path, x: event.clientX, y: event.clientY })
+  }
+
   const handleClosePreviewTabs = (scope: WorkspacePreviewCloseScope) => {
     if (!previewTabContextMenu) return
     closePreviewTabs(sessionId, previewTabContextMenu.tabId, scope)
     setPreviewTabContextMenu(null)
   }
 
+  const copyWorkspacePath = (path: string) => {
+    const resolvedPath = resolveWorkspaceAttachmentPath(status?.workDir, path)
+    void navigator.clipboard?.writeText(resolvedPath)
+    setFileContextMenu(null)
+  }
+
   const renderChangedView = () => {
     if (statusLoading && !status) {
       return <PanelMessage icon="progress_activity" message={t('common.loading')} />
@@ -694,6 +818,7 @@ export function WorkspacePanel({ sessionId }: WorkspacePanelProps) {
             key={`${file.path}:${file.status}:${file.oldPath ?? ''}`}
             file={file}
             onClick={() => handleOpenDiff(file.path)}
+            onContextMenu={handleFileContextMenu}
           />
         ))}
       </div>
@@ -746,6 +871,7 @@ export function WorkspacePanel({ sessionId }: WorkspacePanelProps) {
               void toggleTreeNode(sessionId, path)
             }}
             onOpenFile={handleOpenFile}
+            onFileContextMenu={handleFileContextMenu}
             activePath={activeTreePath}
           />
         ))}
@@ -777,7 +903,15 @@ export function WorkspacePanel({ sessionId }: WorkspacePanelProps) {
               </span>
             </span>
           ))}
-          <span className="ml-auto shrink-0 rounded-[5px] border border-[var(--color-border)] px-1.5 py-0.5 text-[10px] font-medium uppercase tracking-[0.1em] text-[var(--color-text-tertiary)]">
+          <button
+            type="button"
+            onClick={() => addFileToChat(activePreviewTab.path)}
+            className="ml-auto inline-flex h-6 shrink-0 items-center gap-1 rounded-[6px] px-1.5 text-[11px] text-[var(--color-text-secondary)] transition-colors hover:bg-[var(--color-surface-hover)] hover:text-[var(--color-text-primary)]"
+          >
+            <span aria-hidden="true" className="material-symbols-outlined text-[14px]">person_add</span>
+            <span>{t('workspace.addToChat')}</span>
+          </button>
+          <span className="shrink-0 rounded-[5px] border border-[var(--color-border)] px-1.5 py-0.5 text-[10px] font-medium uppercase tracking-[0.1em] text-[var(--color-text-tertiary)]">
             {kindLabel}
           </span>
         </div>
@@ -797,6 +931,7 @@ export function WorkspacePanel({ sessionId }: WorkspacePanelProps) {
           <CodeSurface
             value={activePreviewTab.content ?? ''}
             language={activePreviewTab.language ?? 'text'}
+            onAddLineComment={(line, note, quote) => addLineCommentToChat(activePreviewTab.path, line, note, quote)}
           />
         ) : (
           <PanelMessage
@@ -1002,6 +1137,37 @@ export function WorkspacePanel({ sessionId }: WorkspacePanelProps) {
           {activeView === 'changed' ? renderChangedView() : renderAllFilesView()}
         </div>
       </div>
+
+      {fileContextMenu && (
+        <div
+          role="menu"
+          className="fixed z-50 min-w-[156px] rounded-[10px] border border-[var(--color-border)] bg-[var(--color-surface-container-lowest)] py-1 text-[12px] shadow-[var(--shadow-dropdown)]"
+          style={{ left: fileContextMenu.x, top: fileContextMenu.y }}
+          onClick={(event) => event.stopPropagation()}
+        >
+          <button
+            type="button"
+            role="menuitem"
+            onClick={() => {
+              addFileToChat(fileContextMenu.path)
+              setFileContextMenu(null)
+            }}
+            className="flex w-full items-center gap-2 px-3 py-1.5 text-left text-[var(--color-text-primary)] hover:bg-[var(--color-surface-hover)]"
+          >
+            <span aria-hidden="true" className="material-symbols-outlined text-[14px] text-[var(--color-text-tertiary)]">person_add</span>
+            <span>{t('workspace.addToChat')}</span>
+          </button>
+          <button
+            type="button"
+            role="menuitem"
+            onClick={() => copyWorkspacePath(fileContextMenu.path)}
+            className="flex w-full items-center gap-2 px-3 py-1.5 text-left text-[var(--color-text-primary)] hover:bg-[var(--color-surface-hover)]"
+          >
+            <span aria-hidden="true" className="material-symbols-outlined text-[14px] text-[var(--color-text-tertiary)]">content_copy</span>
+            <span>{t('workspace.copyPath')}</span>
+          </button>
+        </div>
+      )}
     </aside>
   )
 }
diff --git a/desktop/src/i18n/locales/en.ts b/desktop/src/i18n/locales/en.ts
index f19d0eda..811c6bff 100644
--- a/desktop/src/i18n/locales/en.ts
+++ b/desktop/src/i18n/locales/en.ts
@@ -68,6 +68,13 @@ export const en = {
   'workspace.previewState.missing': 'File not found.',
   'workspace.imagePreviewUnavailable': 'Image preview is unavailable.',
   'workspace.previewLineLimit': 'Showing first {count} lines. Open in your editor for the full file.',
+  'workspace.addToChat': 'Add to chat',
+  'workspace.copyPath': 'Copy path',
+  'workspace.localComment': 'Local comment',
+  'workspace.commentLine': 'Comment line {line}',
+  'workspace.commentLineTarget': 'Line {line}',
+  'workspace.commentPlaceholder': 'Describe what should change here...',
+  'workspace.addCommentToChat': 'Add comment',
 
   // ─── Status Bar ──────────────────────────────────────
   'status.connected': 'Connected',
@@ -527,6 +534,7 @@ export const en = {
   'chat.placeholder': 'Ask Claude to edit, debug or explain...',
   'chat.placeholderMissing': 'This session points to a missing workspace. Create a new session or pick another project.',
   'chat.addFiles': 'Add files or photos',
+  'chat.workspaceReferencesOnly': 'Added {count} workspace references',
   'chat.slashCommands': 'Slash commands',
   'slash.mcp.title': 'Available MCP tools',
   'slash.mcp.subtitle': 'Global and current-project MCP servers available in this chat context.',
diff --git a/desktop/src/i18n/locales/zh.ts b/desktop/src/i18n/locales/zh.ts
index 3e721154..a11e9f57 100644
--- a/desktop/src/i18n/locales/zh.ts
+++ b/desktop/src/i18n/locales/zh.ts
@@ -70,6 +70,13 @@ export const zh: Record<TranslationKey, string> = {
   'workspace.previewState.missing': '文件不存在。',
   'workspace.imagePreviewUnavailable': '图片无法预览。',
   'workspace.previewLineLimit': '仅显示前 {count} 行。完整内容请在编辑器中打开。',
+  'workspace.addToChat': '添加到聊天',
+  'workspace.copyPath': '复制路径',
+  'workspace.localComment': '本地评论',
+  'workspace.commentLine': '评论第 {line} 行',
+  'workspace.commentLineTarget': '第 {line} 行',
+  'workspace.commentPlaceholder': '描述你希望这里怎么改...',
+  'workspace.addCommentToChat': '添加评论',
 
   // ─── Status Bar ──────────────────────────────────────
   'status.connected': '已连接',
@@ -529,6 +536,7 @@ export const zh: Record<TranslationKey, string> = {
   'chat.placeholder': '让 Claude 编辑、调试或解释代码...',
   'chat.placeholderMissing': '此会话指向的工作目录缺失。请新建会话或选择其他项目。',
   'chat.addFiles': '添加文件或图片',
+  'chat.workspaceReferencesOnly': '已添加 {count} 个工作区引用',
   'chat.slashCommands': '斜杠命令',
   'slash.mcp.title': '可用 MCP 工具',
   'slash.mcp.subtitle': '展示当前聊天上下文里的全局 MCP 和当前项目 MCP。',
diff --git a/desktop/src/stores/chatStore.test.ts b/desktop/src/stores/chatStore.test.ts
index 03fb897b..66ea673a 100644
--- a/desktop/src/stores/chatStore.test.ts
+++ b/desktop/src/stores/chatStore.test.ts
@@ -231,6 +231,117 @@ describe('chatStore history mapping', () => {
     ])
   })
 
+  it('restores CLI file mentions as visible attachment chips from transcript history', () => {
+    const messages: MessageEntry[] = [
+      {
+        id: 'user-with-file-mention',
+        type: 'user',
+        timestamp: '2026-04-06T00:00:00.000Z',
+        content: '@"/private/tmp/example/src/sentinel.ts" 这个常量是什么？',
+      },
+    ]
+
+    const mapped = mapHistoryMessagesToUiMessages(messages)
+
+    expect(mapped).toMatchObject([
+      {
+        id: 'user-with-file-mention',
+        type: 'user_text',
+        content: '这个常量是什么？',
+        modelContent: '@"/private/tmp/example/src/sentinel.ts" 这个常量是什么？',
+        attachments: [{
+          type: 'file',
+          name: 'sentinel.ts',
+          path: '/private/tmp/example/src/sentinel.ts',
+        }],
+      },
+    ])
+  })
+
+  it('keeps workspace reference chips visible while sending CLI attachment paths', () => {
+    useChatStore.setState({
+      sessions: {
+        [TEST_SESSION_ID]: {
+          messages: [],
+          chatState: 'idle',
+          connectionState: 'connected',
+          streamingText: '',
+          streamingToolInput: '',
+          activeToolUseId: null,
+          activeToolName: null,
+          activeThinkingId: null,
+          pendingPermission: null,
+          pendingComputerUsePermission: null,
+          tokenUsage: { input_tokens: 0, output_tokens: 0 },
+          elapsedSeconds: 0,
+          statusVerb: '',
+          slashCommands: [],
+          agentTaskNotifications: {},
+          elapsedTimer: null,
+        },
+      },
+    })
+
+    useChatStore.getState().sendMessage(
+      TEST_SESSION_ID,
+      'Notes for attached workspace files:\n- src/App.tsx:L4\n  Comment: tighten this',
+      [{
+        type: 'file',
+        name: 'App.tsx',
+        path: '/repo/src/App.tsx',
+        lineStart: 4,
+        lineEnd: 4,
+        note: 'tighten this',
+        quote: 'const value = 1',
+      }],
+      {
+        displayContent: '改这里',
+        displayAttachments: [{
+          type: 'file',
+          name: 'App.tsx',
+          path: 'src/App.tsx',
+          lineStart: 4,
+          lineEnd: 4,
+          note: 'tighten this',
+          quote: 'const value = 1',
+        }],
+      },
+    )
+
+    expect(useChatStore.getState().sessions[TEST_SESSION_ID]?.messages).toMatchObject([
+      {
+        type: 'user_text',
+        content: '改这里',
+        modelContent: 'Notes for attached workspace files:\n- src/App.tsx:L4\n  Comment: tighten this',
+        attachments: [{
+          type: 'file',
+          name: 'App.tsx',
+          path: 'src/App.tsx',
+          lineStart: 4,
+          lineEnd: 4,
+          note: 'tighten this',
+          quote: 'const value = 1',
+        }],
+      },
+    ])
+    expect(sendMock).toHaveBeenCalledWith(
+      TEST_SESSION_ID,
+      {
+        type: 'user_message',
+        content: 'Notes for attached workspace files:\n- src/App.tsx:L4\n  Comment: tighten this',
+        attachments: [{
+          type: 'file',
+          name: 'App.tsx',
+          path: '/repo/src/App.tsx',
+          lineStart: 4,
+          lineEnd: 4,
+          note: 'tighten this',
+          quote: 'const value = 1',
+        }],
+      },
+    )
+  })
+
   it('keeps parent tool linkage for live tool events', () => {
     // Initialize the session first
     useChatStore.setState({
diff --git a/desktop/src/stores/chatStore.ts b/desktop/src/stores/chatStore.ts
index 01701006..adeff337 100644
--- a/desktop/src/stores/chatStore.ts
+++ b/desktop/src/stores/chatStore.ts
@@ -92,7 +92,7 @@ type ChatStore = {
     sessionId: string,
     content: string,
     attachments?: AttachmentRef[],
-    options?: { displayContent?: string },
+    options?: { displayContent?: string; displayAttachments?: AttachmentRef[] },
   ) => void
   respondToPermission: (
     sessionId: string,
@@ -265,13 +265,19 @@ export const useChatStore = create<ChatStore>((set, get) => ({
     const userFacingContent =
       options?.displayContent?.trim() || content.trim()
     const isMemberSession = !!useTeamStore.getState().getMemberBySessionId(sessionId)
+    const visibleAttachments = options?.displayAttachments ?? attachments
     const uiAttachments: UIAttachment[] | undefined =
-      attachments && attachments.length > 0
-        ? attachments.map((a) => ({
+      visibleAttachments && visibleAttachments.length > 0
+        ? visibleAttachments.map((a) => ({
             type: a.type,
             name: a.name || a.path || a.mimeType || a.type,
+            path: a.path,
             data: a.data,
             mimeType: a.mimeType,
+            lineStart: a.lineStart,
+            lineEnd: a.lineEnd,
+            note: a.note,
+            quote: a.quote,
           }))
         : undefined
 
@@ -309,6 +315,7 @@ export const useChatStore = create<ChatStore>((set, get) => ({
         id: nextId(),
         type: 'user_text',
         content: userFacingContent,
+        ...(userFacingContent !== content ? { modelContent: content } : {}),
         attachments: isMemberSession ? undefined : uiAttachments,
         timestamp: Date.now(),
         ...(isMemberSession ? { pending: true } : {}),
@@ -918,6 +925,43 @@ type HistoryMappingOptions = {
   includeTeammateMessages?: boolean
 }
 
+function getReferenceName(referencePath: string): string {
+  const normalized = referencePath.replace(/\\/g, '/').replace(/\/+$/, '')
+  const name = normalized.split('/').filter(Boolean).pop()
+  return name || referencePath
+}
+
+function extractLeadingFileReferences(text: string): {
+  content: string
+  attachments?: UIAttachment[]
+  modelContent?: string
+} {
+  const attachments: UIAttachment[] = []
+  let remaining = text
+
+  while (true) {
+    const match = remaining.match(/^@"([^"]+)"\s*/)
+    if (!match?.[1]) break
+
+    attachments.push({
+      type: 'file',
+      name: getReferenceName(match[1]),
+      path: match[1],
+    })
+    remaining = remaining.slice(match[0].length)
+  }
+
+  if (attachments.length === 0) {
+    return { content: text }
+  }
+
+  return {
+    content: remaining.trimStart(),
+    attachments,
+    modelContent: text,
+  }
+}
+
 /**
  * Reconstruct agentTaskNotifications from history.
  *
@@ -1013,7 +1057,15 @@ export function mapHistoryMessagesToUiMessages(
         })
         continue
       }
-      uiMessages.push({ id: msg.id || nextId(), type: 'user_text', content: msg.content, timestamp })
+      const parsed = extractLeadingFileReferences(msg.content)
+      uiMessages.push({
+        id: msg.id || nextId(),
+        type: 'user_text',
+        content: parsed.content,
+        ...(parsed.modelContent ? { modelContent: parsed.modelContent } : {}),
+        ...(parsed.attachments ? { attachments: parsed.attachments } : {}),
+        timestamp,
+      })
       continue
     }
     if (msg.type === 'assistant' && typeof msg.content === 'string') {
@@ -1043,7 +1095,16 @@ export function mapHistoryMessagesToUiMessages(
         else if (block.type === 'tool_result') uiMessages.push({ id: nextId(), type: 'tool_result', toolUseId: block.tool_use_id ?? '', content: block.content, isError: !!block.is_error, timestamp, parentToolUseId: msg.parentToolUseId })
       }
       if (textParts.length > 0 || attachments.length > 0) {
-        uiMessages.push({ id: msg.id || nextId(), type: 'user_text', content: textParts.join('\n'), attachments: attachments.length > 0 ? attachments : undefined, timestamp })
+        const parsed = extractLeadingFileReferences(textParts.join('\n'))
+        const allAttachments = [...(parsed.attachments ?? []), ...attachments]
+        uiMessages.push({
+          id: msg.id || nextId(),
+          type: 'user_text',
+          content: parsed.content,
+          ...(parsed.modelContent ? { modelContent: parsed.modelContent } : {}),
+          attachments: allAttachments.length > 0 ? allAttachments : undefined,
+          timestamp,
+        })
       }
     }
   }
diff --git a/desktop/src/stores/workspaceChatContextStore.test.ts b/desktop/src/stores/workspaceChatContextStore.test.ts
new file mode 100644
index 00000000..6194d523
--- /dev/null
+++ b/desktop/src/stores/workspaceChatContextStore.test.ts
@@ -0,0 +1,69 @@
+import { beforeEach, describe, expect, it } from 'vitest'
+import {
+  formatWorkspaceReferencePrompt,
+  useWorkspaceChatContextStore,
+} from './workspaceChatContextStore'
+
+const initialState = useWorkspaceChatContextStore.getInitialState()
+
+describe('workspaceChatContextStore', () => {
+  beforeEach(() => {
+    useWorkspaceChatContextStore.setState(initialState, true)
+  })
+
+  it('deduplicates file references per session', () => {
+    const store = useWorkspaceChatContextStore.getState()
+
+    store.addReference('session-1', {
+      kind: 'file',
+      path: 'src/App.tsx',
+      absolutePath: '/repo/src/App.tsx',
+      name: 'App.tsx',
+    })
+    store.addReference('session-1', {
+      kind: 'file',
+      path: 'src/App.tsx',
+      absolutePath: '/repo/src/App.tsx',
+      name: 'App.tsx',
+    })
+
+    expect(useWorkspaceChatContextStore.getState().referencesBySession['session-1']).toHaveLength(1)
+  })
+
+  it('formats line comments into the request prompt', () => {
+    const prompt = formatWorkspaceReferencePrompt([
+      {
+        id: 'ref-1',
+        kind: 'code-comment',
+        path: 'src/App.tsx',
+        absolutePath: '/repo/src/App.tsx',
+        name: 'App.tsx',
+        lineStart: 12,
+        lineEnd: 12,
+        note: 'Use a clearer name',
+        quote: 'const value = 1',
+      },
+    ])
+
+    expect(prompt).toContain('Notes for attached workspace files:')
+    expect(prompt).toContain('- src/App.tsx:L12')
+    expect(prompt).toContain('Comment: Use a clearer name')
+    expect(prompt).toContain('Selected code: const value = 1')
+    expect(prompt).not.toContain('Use the Read tool')
+    expect(prompt).not.toContain('Path: /repo/src/App.tsx')
+  })
+
+  it('does not add prompt text for plain file attachments', () => {
+    const prompt = formatWorkspaceReferencePrompt([
+      {
+        id: 'ref-1',
+        kind: 'file',
+        path: 'src/App.tsx',
+        absolutePath: '/repo/src/App.tsx',
+        name: 'App.tsx',
+      },
+    ])
+
+    expect(prompt).toBe('')
+  })
+})
diff --git a/desktop/src/stores/workspaceChatContextStore.ts b/desktop/src/stores/workspaceChatContextStore.ts
new file mode 100644
index 00000000..8d055019
--- /dev/null
+++ b/desktop/src/stores/workspaceChatContextStore.ts
@@ -0,0 +1,118 @@
+import { create } from 'zustand'
+
+export type WorkspaceChatReferenceKind = 'file' | 'code-comment'
+
+export type WorkspaceChatReference = {
+  id: string
+  kind: WorkspaceChatReferenceKind
+  path: string
+  absolutePath?: string
+  name: string
+  lineStart?: number
+  lineEnd?: number
+  note?: string
+  quote?: string
+}
+
+type WorkspaceChatContextStore = {
+  referencesBySession: Record<string, WorkspaceChatReference[] | undefined>
+  addReference: (
+    sessionId: string,
+    reference: Omit<WorkspaceChatReference, 'id'> & { id?: string },
+  ) => void
+  removeReference: (sessionId: string, referenceId: string) => void
+  clearReferences: (sessionId: string) => void
+  clearSession: (sessionId: string) => void
+}
+
+function makeReferenceId(reference: Omit<WorkspaceChatReference, 'id'>) {
+  const linePart = reference.lineStart
+    ? `${reference.lineStart}-${reference.lineEnd ?? reference.lineStart}`
+    : 'file'
+  const notePart = reference.note ? reference.note.slice(0, 48) : ''
+  return `${reference.kind}:${reference.path}:${linePart}:${notePart}`
+}
+
+function getReferenceDedupKey(reference: WorkspaceChatReference) {
+  if (reference.kind === 'file') return `${reference.kind}:${reference.path}`
+  return `${reference.kind}:${reference.path}:${reference.lineStart ?? ''}:${reference.lineEnd ?? ''}:${reference.note ?? ''}`
+}
+
+export function formatWorkspaceReferenceLocation(reference: WorkspaceChatReference) {
+  if (!reference.lineStart) return reference.path
+  const lineEnd = reference.lineEnd && reference.lineEnd !== reference.lineStart
+    ? `-L${reference.lineEnd}`
+    : ''
+  return `${reference.path}:L${reference.lineStart}${lineEnd}`
+}
+
+export function formatWorkspaceReferencePrompt(references: WorkspaceChatReference[]) {
+  const referencesWithContext = references.filter((reference) =>
+    reference.kind === 'code-comment' ||
+    !!reference.lineStart ||
+    !!reference.note?.trim() ||
+    !!reference.quote?.trim(),
+  )
+  if (referencesWithContext.length === 0) return ''
+
+  const lines = [
+    'Notes for attached workspace files:',
+    ...referencesWithContext.map((reference) => {
+      const location = formatWorkspaceReferenceLocation(reference)
+      const parts = [`- ${location}`]
+      if (reference.note?.trim()) parts.push(`Comment: ${reference.note.trim()}`)
+      if (reference.quote?.trim()) parts.push(`Selected code: ${reference.quote.trim()}`)
+      return parts.join('\n  ')
+    }),
+  ]
+
+  return lines.join('\n')
+}
+
+export const useWorkspaceChatContextStore = create<WorkspaceChatContextStore>((set) => ({
+  referencesBySession: {},
+
+  addReference: (sessionId, input) =>
+    set((state) => {
+      const reference: WorkspaceChatReference = {
+        ...input,
+        id: input.id ?? makeReferenceId(input),
+      }
+      const existing = state.referencesBySession[sessionId] ?? []
+      const nextKey = getReferenceDedupKey(reference)
+      const withoutDuplicate = existing.filter((item) => getReferenceDedupKey(item) !== nextKey)
+
+      return {
+        referencesBySession: {
+          ...state.referencesBySession,
+          [sessionId]: [...withoutDuplicate, reference],
+        },
+      }
+    }),
+
+  removeReference: (sessionId, referenceId) =>
+    set((state) => {
+      const existing = state.referencesBySession[sessionId] ?? []
+      return {
+        referencesBySession: {
+          ...state.referencesBySession,
+          [sessionId]: existing.filter((reference) => reference.id !== referenceId),
+        },
+      }
+    }),
+
+  clearReferences: (sessionId) =>
+    set((state) => ({
+      referencesBySession: {
+        ...state.referencesBySession,
+        [sessionId]: [],
+      },
+    })),
+
+  clearSession: (sessionId) =>
+    set((state) => {
+      if (!(sessionId in state.referencesBySession)) return state
+      const { [sessionId]: _removed, ...rest } = state.referencesBySession
+      return { referencesBySession: rest }
+    }),
+}))
diff --git a/desktop/src/types/chat.ts b/desktop/src/types/chat.ts
index c0c0247d..cd2b63da 100644
--- a/desktop/src/types/chat.ts
+++ b/desktop/src/types/chat.ts
@@ -31,13 +31,22 @@ export type AttachmentRef = {
   path?: string
   data?: string
   mimeType?: string
+  lineStart?: number
+  lineEnd?: number
+  note?: string
+  quote?: string
 }
 
 export type UIAttachment = {
   type: 'file' | 'image'
   name: string
+  path?: string
   data?: string
   mimeType?: string
+  lineStart?: number
+  lineEnd?: number
+  note?: string
+  quote?: string
 }
 
 // ─── Server → Client ──────────────────────────────────────────────
@@ -157,7 +166,7 @@ export type TaskSummaryItem = {
 }
 
 export type UIMessage =
-  | { id: string; type: 'user_text'; content: string; timestamp: number; attachments?: UIAttachment[]; pending?: boolean }
+  | { id: string; type: 'user_text'; content: string; modelContent?: string; timestamp: number; attachments?: UIAttachment[]; pending?: boolean }
   | { id: string; type: 'assistant_text'; content: string; timestamp: number; model?: string }
   | { id: string; type: 'thinking'; content: string; timestamp: number }
   | { id: string; type: 'tool_use'; toolName: string; toolUseId: string; input: unknown; timestamp: number; parentToolUseId?: string }