Merge selected chat context references

2026-07-17 13:13:35 +08:00 · 2026-05-13 14:08:24 +08:00 · 2026-05-13 14:08:24 +08:00 · 523db62b3b
commit 523db62b3b
parent be01a64f1c 52b11697e1
12 changed files with 1066 additions and 55 deletions
--- a/desktop/src/components/chat/AttachmentGallery.test.tsx
+++ b/desktop/src/components/chat/AttachmentGallery.test.tsx
@ -0,0 +1,67 @@
+// @vitest-environment jsdom
+
+import { fireEvent, render } from '@testing-library/react'
+import { describe, expect, it, vi } from 'vitest'
+import { AttachmentGallery } from './AttachmentGallery'
+
+describe('AttachmentGallery', () => {
+  it('renders a compact quote preview for selected workspace text', () => {
+    render(
+      <AttachmentGallery
+        variant="composer"
+        attachments={[{
+          id: 'selection-1',
+          type: 'file',
+          name: 'App.tsx',
+          path: 'src/App.tsx',
+          lineStart: 10,
+          lineEnd: 12,
+          quote: 'const value = calculate(input)\nreturn value',
+        }]}
+      />,
+    )
+
+    expect(document.body.textContent).toContain('App.tsx:L10-L12')
+    expect(document.body.textContent).toContain('const value = calculate(input) return value')
+  })
+
+  it('keeps plain file chips on the one-line treatment', () => {
+    render(
+      <AttachmentGallery
+        variant="composer"
+        attachments={[{
+          id: 'file-1',
+          type: 'file',
+          name: 'README.md',
+          path: 'README.md',
+        }]}
+      />,
+    )
+
+    expect(document.body.textContent).toContain('README.md')
+    expect(document.body.textContent).not.toContain(':L')
+  })
+
+  it('removes a quoted workspace attachment by id', () => {
+    const onRemove = vi.fn()
+
+    const view = render(
+      <AttachmentGallery
+        variant="composer"
+        onRemove={onRemove}
+        attachments={[{
+          id: 'selection-1',
+          type: 'file',
+          name: 'App.tsx',
+          path: 'src/App.tsx',
+          lineStart: 10,
+          quote: 'const value = 1',
+        }]}
+      />,
+    )
+
+    fireEvent.click(view.getByRole('button', { name: 'Remove App.tsx' }))
+
+    expect(onRemove).toHaveBeenCalledWith('selection-1')
+  })
+})
--- a/desktop/src/components/chat/AttachmentGallery.tsx
+++ b/desktop/src/components/chat/AttachmentGallery.tsx
@ -83,29 +83,41 @@ export function AttachmentGallery({ attachments, variant = 'message', onRemove }
            )
          }

+          const lineLabel = attachment.lineStart
+            ? `:L${attachment.lineStart}${attachment.lineEnd && attachment.lineEnd !== attachment.lineStart ? `-L${attachment.lineEnd}` : ''}`
+            : ''
+          const quotePreview = attachment.quote?.trim().replace(/\s+/g, ' ')
+          const hasQuotePreview = !!quotePreview
+
          return (
            <div
              key={attachment.id || `${attachment.name}-${index}`}
              className={[
-                'group/file inline-flex max-w-full min-w-0 items-center gap-2 rounded-full border border-[var(--color-border)]',
+                'group/file inline-flex max-w-full min-w-0 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',
+                hasQuotePreview
+                  ? 'items-start gap-2 rounded-[8px] px-2.5 py-2'
+                  : 'h-9 items-center gap-2 rounded-full px-3',
              ].join(' ')}
            >
-              <span className="material-symbols-outlined shrink-0 text-[17px] text-[var(--color-text-tertiary)]">
-                {attachment.lineStart ? 'chat_bubble' : attachment.isDirectory ? 'folder' : 'description'}
+              <span className={`material-symbols-outlined shrink-0 text-[17px] text-[var(--color-text-tertiary)] ${hasQuotePreview ? 'mt-0.5' : ''}`}>
+                {hasQuotePreview ? 'chat_bubble' : attachment.isDirectory ? 'folder' : 'description'}
              </span>
-              <span className="min-w-0 max-w-[220px] truncate text-[13px] font-medium leading-none text-[var(--color-text-primary)]">
-                {attachment.name}
-                {attachment.lineStart
-                  ? `:L${attachment.lineStart}${attachment.lineEnd && attachment.lineEnd !== attachment.lineStart ? `-L${attachment.lineEnd}` : ''}`
-                  : ''}
+              <span className="min-w-0">
+                <span className="block min-w-0 max-w-[260px] truncate text-[13px] font-medium leading-5 text-[var(--color-text-primary)]">
+                  {attachment.name}{lineLabel}
+                </span>
+                {hasQuotePreview && (
+                  <span className="mt-0.5 block max-w-[320px] truncate font-[var(--font-mono)] text-[11px] leading-4 text-[var(--color-text-tertiary)]">
+                    {quotePreview}
+                  </span>
+                )}
              </span>
              {onRemove && attachment.id && (
                <button
                  type="button"
                  onClick={() => onRemove(attachment.id!)}
-                  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)]"
+                  className={`${hasQuotePreview ? 'mt-0.5' : '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-[17px]">close</span>
--- a/desktop/src/components/chat/ChatInput.tsx
+++ b/desktop/src/components/chat/ChatInput.tsx
@ -66,7 +66,7 @@ function workspaceReferenceToAttachment(reference: WorkspaceChatReference): Atta
    id: reference.id,
    name: reference.name,
    type: 'file',
-    path: reference.path,
+    path: reference.kind === 'chat-selection' ? undefined : reference.path,
    isDirectory: reference.isDirectory,
    lineStart: reference.lineStart,
    lineEnd: reference.lineEnd,
@ -519,7 +519,7 @@ export function ChatInput({ variant = 'default', compact = false }: ChatInputPro
    const contentForModel = [workspaceReferencePrompt, text].filter(Boolean).join('\n\n')
    const displayContent = text || (
      workspaceReferences.length > 0
-        ? t('chat.workspaceReferencesOnly', { count: workspaceReferences.length })
+        ? t('chat.contextReferencesOnly', { count: workspaceReferences.length })
        : ''
    )
    const uploadAttachmentPayload: AttachmentRef[] = attachments.map((attachment) => ({
@ -533,22 +533,24 @@ export function ChatInput({ variant = 'default', compact = false }: ChatInputPro
      note: attachment.note,
      quote: attachment.quote,
    }))
-    const workspaceAttachmentPayload: AttachmentRef[] = workspaceReferences.map((reference) => ({
-      type: 'file' as const,
-      name: reference.name,
-      path: reference.absolutePath ?? reference.path,
-      isDirectory: reference.isDirectory,
-      lineStart: reference.lineStart,
-      lineEnd: reference.lineEnd,
-      note: reference.note,
-      quote: reference.quote,
-    }))
+    const workspaceAttachmentPayload: AttachmentRef[] = workspaceReferences
+      .filter((reference) => reference.kind !== 'chat-selection')
+      .map((reference) => ({
+        type: 'file' as const,
+        name: reference.name,
+        path: reference.absolutePath ?? reference.path,
+        isDirectory: reference.isDirectory,
+        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,
+        path: reference.kind === 'chat-selection' ? undefined : reference.path,
        isDirectory: reference.isDirectory,
        lineStart: reference.lineStart,
        lineEnd: reference.lineEnd,
--- a/desktop/src/components/chat/MessageList.test.tsx
+++ b/desktop/src/components/chat/MessageList.test.tsx
@ -4,6 +4,7 @@ import { MessageList, buildRenderModel } from './MessageList'
 import { relativizeWorkspacePath } from './CurrentTurnChangeCard'
 import { sessionsApi } from '../../api/sessions'
 import { useChatStore } from '../../stores/chatStore'
+import { useWorkspaceChatContextStore } from '../../stores/workspaceChatContextStore'
 import { useSettingsStore } from '../../stores/settingsStore'
 import { useTabStore } from '../../stores/tabStore'
 import type { UIMessage } from '../../types/chat'
@ -42,12 +43,67 @@ function makeSessionState(overrides: Partial<PerSessionState> = {}): PerSessionS
  }
 }

+function findTextNodeContaining(container: Element, text: string) {
+  const walker = document.createTreeWalker(container, 4)
+  let current = walker.nextNode()
+  while (current) {
+    if (current.textContent?.includes(text)) return current
+    current = walker.nextNode()
+  }
+  throw new Error(`Unable to find text node containing ${text}`)
+}
+
+async function selectMessageText(element: Element, text: string) {
+  const textNode = findTextNodeContaining(element, text)
+  const startOffset = textNode.textContent?.indexOf(text) ?? -1
+  const range = document.createRange()
+  range.setStart(textNode, startOffset)
+  range.setEnd(textNode, startOffset + text.length)
+  Object.assign(range, {
+    getBoundingClientRect: () => ({
+      left: 160,
+      top: 80,
+      right: 280,
+      bottom: 98,
+      width: 120,
+      height: 18,
+      x: 160,
+      y: 80,
+      toJSON: () => ({}),
+    }),
+  })
+
+  const selectableRoot = element.closest('[data-message-shell]')?.parentElement?.parentElement
+  Object.assign(selectableRoot ?? element, {
+    getBoundingClientRect: () => ({
+      left: 120,
+      top: 48,
+      right: 620,
+      bottom: 240,
+      width: 500,
+      height: 192,
+      x: 120,
+      y: 48,
+      toJSON: () => ({}),
+    }),
+  })
+
+  window.getSelection()?.removeAllRanges()
+  window.getSelection()?.addRange(range)
+
+  await act(async () => {
+    fireEvent.mouseUp(element, { clientX: 260, clientY: 104 })
+    await Promise.resolve()
+  })
+}
+
 describe('MessageList nested tool calls', () => {
  beforeEach(() => {
    vi.restoreAllMocks()
    useSettingsStore.setState({ locale: 'en' })
    useTabStore.setState({ activeTabId: ACTIVE_TAB, tabs: [{ sessionId: ACTIVE_TAB, title: 'Test', type: 'session' as const, status: 'idle' }] })
    useChatStore.setState({ sessions: { [ACTIVE_TAB]: makeSessionState() } })
+    useWorkspaceChatContextStore.setState(useWorkspaceChatContextStore.getInitialState(), true)
    vi.spyOn(sessionsApi, 'getTurnCheckpoints').mockImplementation(
      () => new Promise(() => {}),
    )
@ -429,6 +485,76 @@ describe('MessageList nested tool calls', () => {
    )
  })

+  it('adds selected user message text to the composer context', async () => {
+    useChatStore.setState({
+      sessions: {
+        [ACTIVE_TAB]: makeSessionState({
+          messages: [{
+            id: 'user-1',
+            type: 'user_text',
+            content: 'Please inspect the workspace selection behavior.',
+            timestamp: 1,
+          }],
+        }),
+      },
+    })
+
+    render(<MessageList />)
+
+    const userText = screen.getByText('Please inspect the workspace selection behavior.')
+    await selectMessageText(userText, 'workspace selection behavior')
+    const floatingAddButton = screen.getByRole('button', { name: 'Add to chat' })
+
+    expect(floatingAddButton.style.left).toBe('260px')
+    expect(floatingAddButton.style.top).toBe('112px')
+
+    fireEvent.click(floatingAddButton)
+
+    expect(useWorkspaceChatContextStore.getState().referencesBySession[ACTIVE_TAB]).toMatchObject([
+      {
+        kind: 'chat-selection',
+        path: 'chat://user/user-1',
+        name: 'User message',
+        messageId: 'user-1',
+        sourceRole: 'user',
+        quote: 'workspace selection behavior',
+      },
+    ])
+    expect(window.getSelection()?.toString()).toBe('')
+  })
+
+  it('adds selected assistant reply text to the composer context', async () => {
+    useChatStore.setState({
+      sessions: {
+        [ACTIVE_TAB]: makeSessionState({
+          messages: [{
+            id: 'assistant-1',
+            type: 'assistant_text',
+            content: 'First inspect the file tree. Then quote the selected lines.',
+            timestamp: 1,
+          }],
+        }),
+      },
+    })
+
+    render(<MessageList />)
+
+    const assistantText = screen.getByText(/First inspect the file tree/)
+    await selectMessageText(assistantText, 'quote the selected lines')
+    fireEvent.click(screen.getByRole('button', { name: 'Add to chat' }))
+
+    expect(useWorkspaceChatContextStore.getState().referencesBySession[ACTIVE_TAB]).toMatchObject([
+      {
+        kind: 'chat-selection',
+        path: 'chat://assistant/assistant-1',
+        name: 'Assistant message',
+        messageId: 'assistant-1',
+        sourceRole: 'assistant',
+        quote: 'quote the selected lines',
+      },
+    ])
+  })
+
  it('does not force-scroll to the bottom while the user is reading history', async () => {
    const scrollIntoView = vi.fn()
    Object.defineProperty(HTMLElement.prototype, 'scrollIntoView', {
--- a/desktop/src/components/chat/MessageList.tsx
+++ b/desktop/src/components/chat/MessageList.tsx
@ -1,8 +1,9 @@
-import { useRef, useEffect, useMemo, memo, useState, useCallback, useLayoutEffect } from 'react'
+import { useRef, useEffect, useMemo, memo, useState, useCallback, useLayoutEffect, type ReactNode } from 'react'
 import { ArrowDown } from 'lucide-react'
 import { ApiError } from '../../api/client'
 import { sessionsApi, type SessionTurnCheckpoint } from '../../api/sessions'
 import { useChatStore } from '../../stores/chatStore'
+import { useWorkspaceChatContextStore } from '../../stores/workspaceChatContextStore'
 import { useTabStore } from '../../stores/tabStore'
 import { useTeamStore } from '../../stores/teamStore'
 import { useUIStore } from '../../stores/uiStore'
@ -50,6 +51,157 @@ type TurnChangeCardModel = {
  isLatest: boolean
 }

+type ChatMessageRole = 'user' | 'assistant'
+
+type ChatSelectionState = {
+  text: string
+  x: number
+  y: number
+}
+
+const CHAT_SELECTION_MENU_OFFSET = 8
+
+function clampValue(value: number, min: number, max: number) {
+  return Math.max(min, Math.min(value, max))
+}
+
+function getElementForNode(node: Node | null): Element | null {
+  if (!node) return null
+  return node.nodeType === Node.ELEMENT_NODE ? node as Element : node.parentElement
+}
+
+function getChatSelectionPosition(range: Range, root: HTMLElement, pointer: { clientX: number; clientY: number }) {
+  const rect = typeof range.getBoundingClientRect === 'function'
+    ? range.getBoundingClientRect()
+    : null
+  const rootRect = root.getBoundingClientRect()
+  const pointerInsideRoot =
+    pointer.clientX >= rootRect.left &&
+    pointer.clientX <= rootRect.right &&
+    pointer.clientY >= rootRect.top &&
+    pointer.clientY <= rootRect.bottom
+  const fallbackX = rect && rect.width > 0
+    ? rect.left + rect.width / 2
+    : rect?.left ?? rootRect.left + 24
+  const fallbackY = rect
+    ? rect.bottom + CHAT_SELECTION_MENU_OFFSET
+    : rootRect.top + 24
+  const unclampedX = pointerInsideRoot ? pointer.clientX : fallbackX
+  const unclampedY = pointerInsideRoot ? pointer.clientY + CHAT_SELECTION_MENU_OFFSET : fallbackY
+  const minX = Math.max(12, rootRect.left + 8)
+  const maxX = Math.max(minX, Math.min(window.innerWidth - 160, rootRect.right - 136))
+  const minY = Math.max(12, rootRect.top + 8)
+  const maxY = Math.max(minY, Math.min(window.innerHeight - 48, rootRect.bottom - 40))
+
+  return {
+    x: clampValue(unclampedX, minX, maxX),
+    y: clampValue(unclampedY, minY, maxY),
+  }
+}
+
+function getChatSelectionFromContainer(
+  root: HTMLElement | null,
+  pointer: { clientX: number; clientY: number },
+): ChatSelectionState | null {
+  if (!root) return null
+  const selection = window.getSelection()
+  if (!selection || selection.isCollapsed || selection.rangeCount === 0) return null
+
+  const range = selection.getRangeAt(0)
+  const startElement = getElementForNode(range.startContainer)
+  const endElement = getElementForNode(range.endContainer)
+  if (!startElement || !endElement || !root.contains(startElement) || !root.contains(endElement)) {
+    return null
+  }
+
+  const text = selection.toString().trim()
+  if (!text) return null
+
+  return {
+    ...getChatSelectionPosition(range, root, pointer),
+    text,
+  }
+}
+
+function ChatSelectionMenu({
+  selection,
+  onAdd,
+}: {
+  selection: ChatSelectionState | null
+  onAdd: () => void
+}) {
+  const t = useTranslation()
+  if (!selection) return null
+
+  return (
+    <button
+      type="button"
+      onMouseDown={(event) => event.preventDefault()}
+      onClick={onAdd}
+      className="fixed z-50 inline-flex h-8 items-center gap-1.5 rounded-[8px] border border-[var(--color-border)] bg-[var(--color-surface-container-lowest)] px-2.5 text-[12px] font-medium text-[var(--color-text-primary)] shadow-[var(--shadow-dropdown)] transition-colors hover:bg-[var(--color-surface-hover)] focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-[var(--color-brand)]/35"
+      style={{ left: selection.x, top: selection.y }}
+    >
+      <span aria-hidden="true" className="material-symbols-outlined text-[15px] text-[var(--color-text-tertiary)]">person_add</span>
+      <span>{t('chat.addSelectionToChat')}</span>
+    </button>
+  )
+}
+
+function SelectableChatMessage({
+  sessionId,
+  messageId,
+  role,
+  content,
+  children,
+}: {
+  sessionId?: string | null
+  messageId: string
+  role: ChatMessageRole
+  content: string
+  children: ReactNode
+}) {
+  const rootRef = useRef<HTMLDivElement>(null)
+  const addReference = useWorkspaceChatContextStore((state) => state.addReference)
+  const [selectionMenu, setSelectionMenu] = useState<ChatSelectionState | null>(null)
+  const t = useTranslation()
+  const sourceName = role === 'assistant'
+    ? t('chat.assistantMessageReference')
+    : t('chat.userMessageReference')
+
+  useEffect(() => {
+    setSelectionMenu(null)
+  }, [content, messageId])
+
+  const addCurrentSelectionToChat = useCallback(() => {
+    if (!sessionId || !selectionMenu) return
+    addReference(sessionId, {
+      kind: 'chat-selection',
+      path: `chat://${role}/${messageId}`,
+      name: sourceName,
+      quote: selectionMenu.text,
+      sourceRole: role,
+      messageId,
+    })
+    setSelectionMenu(null)
+    window.getSelection()?.removeAllRanges()
+  }, [addReference, messageId, role, selectionMenu, sessionId, sourceName])
+
+  return (
+    <div
+      ref={rootRef}
+      onMouseUp={(event) => {
+        setSelectionMenu(getChatSelectionFromContainer(rootRef.current, event))
+      }}
+      onKeyDown={(event) => {
+        if (event.key === 'Escape') setSelectionMenu(null)
+      }}
+    >
+      {children}
+      <ChatSelectionMenu selection={selectionMenu} onAdd={addCurrentSelectionToChat} />
+    </div>
+  )
+}
+
 function appendChildToolCall(
  childToolCallsByParent: Map<string, ToolCall[]>,
  parentToolUseId: string,
@ -671,13 +823,29 @@ export const MessageBlock = memo(function MessageBlock({
  switch (message.type) {
    case 'user_text':
      return (
-        <UserMessage
+        <SelectableChatMessage
+          sessionId={sessionId}
+          messageId={message.id}
+          role="user"
          content={message.content}
-          attachments={message.attachments}
-        />
+        >
+          <UserMessage
+            content={message.content}
+            attachments={message.attachments}
+          />
+        </SelectableChatMessage>
      )
    case 'assistant_text':
-      return <AssistantMessage content={message.content} />
+      return (
+        <SelectableChatMessage
+          sessionId={sessionId}
+          messageId={message.id}
+          role="assistant"
+          content={message.content}
+        >
+          <AssistantMessage content={message.content} />
+        </SelectableChatMessage>
+      )
    case 'thinking':
      return <ThinkingBlock content={message.content} isActive={message.id === activeThinkingId} />
    case 'tool_use':
--- a/desktop/src/components/workspace/WorkspacePanel.test.tsx
+++ b/desktop/src/components/workspace/WorkspacePanel.test.tsx
@ -98,6 +98,118 @@ async function clickElement(element: Element) {
  await flushReactWork()
 }

+function findTextNodeContaining(container: Element, text: string) {
+  const walker = document.createTreeWalker(container, 4)
+  let current = walker.nextNode()
+  while (current) {
+    if (current.textContent?.includes(text)) return current
+    current = walker.nextNode()
+  }
+  throw new Error(`Unable to find text node containing ${text}`)
+}
+
+async function selectWorkspaceCodeText(
+  view: Awaited<ReturnType<typeof renderPanel>>,
+  startLine: number,
+  startText: string,
+  endLine: number,
+  endText: string,
+) {
+  const code = view.getByTestId('workspace-code')
+  const startRow = code.querySelector(`[data-workspace-line-number="${startLine}"]`)
+  const endRow = code.querySelector(`[data-workspace-line-number="${endLine}"]`)
+  if (!startRow || !endRow) throw new Error('Selection rows were not rendered')
+
+  Object.assign(code.parentElement?.parentElement ?? code, {
+    getBoundingClientRect: () => ({
+      left: 100,
+      top: 24,
+      right: 520,
+      bottom: 420,
+      width: 420,
+      height: 396,
+      x: 100,
+      y: 24,
+      toJSON: () => ({}),
+    }),
+  })
+
+  const startNode = findTextNodeContaining(startRow, startText)
+  const endNode = findTextNodeContaining(endRow, endText)
+  const startOffset = startNode.textContent?.indexOf(startText) ?? -1
+  const endOffset = (endNode.textContent?.indexOf(endText) ?? -1) + endText.length
+  const range = document.createRange()
+  range.setStart(startNode, startOffset)
+  range.setEnd(endNode, endOffset)
+  Object.assign(range, {
+    getBoundingClientRect: () => ({
+      left: 120,
+      top: 40,
+      right: 240,
+      bottom: 58,
+      width: 120,
+      height: 18,
+      x: 120,
+      y: 40,
+      toJSON: () => ({}),
+    }),
+  })
+
+  const selection = window.getSelection()
+  selection?.removeAllRanges()
+  selection?.addRange(range)
+
+  await act(async () => {
+    fireEvent.mouseUp(code, { clientX: 180, clientY: 72 })
+    await Promise.resolve()
+  })
+  await flushReactWork()
+}
+
+async function selectRenderedText(container: Element, text: string, target?: Element) {
+  const textNode = findTextNodeContaining(container, text)
+  const startOffset = textNode.textContent?.indexOf(text) ?? -1
+  const range = document.createRange()
+  range.setStart(textNode, startOffset)
+  range.setEnd(textNode, startOffset + text.length)
+  Object.assign(range, {
+    getBoundingClientRect: () => ({
+      left: 130,
+      top: 60,
+      right: 260,
+      bottom: 78,
+      width: 130,
+      height: 18,
+      x: 130,
+      y: 60,
+      toJSON: () => ({}),
+    }),
+  })
+  Object.assign(target ?? container, {
+    getBoundingClientRect: () => ({
+      left: 100,
+      top: 24,
+      right: 520,
+      bottom: 420,
+      width: 420,
+      height: 396,
+      x: 100,
+      y: 24,
+      toJSON: () => ({}),
+    }),
+  })
+
+  const selection = window.getSelection()
+  selection?.removeAllRanges()
+  selection?.addRange(range)
+
+  await act(async () => {
+    fireEvent.mouseUp(target ?? container, { clientX: 190, clientY: 80 })
+    await Promise.resolve()
+  })
+  await flushReactWork()
+}
+
 function classNameContains(element: Element | null, needle: string) {
  let current = element
  while (current) {
@ -1145,6 +1257,184 @@ describe('WorkspacePanel', () => {
    ])
  })

+  it('adds selected code from a preview to the chat context without requiring a note', async () => {
+    await setWorkspaceState((state) => ({
+      ...state,
+      panelBySession: {
+        ...state.panelBySession,
+        'session-code-selection': {
+          isOpen: true,
+          activeView: 'all',
+        },
+      },
+      statusBySession: {
+        ...state.statusBySession,
+        'session-code-selection': {
+          state: 'ok',
+          workDir: '/repo',
+          repoName: 'repo',
+          branch: 'main',
+          isGitRepo: true,
+          changedFiles: [],
+        },
+      },
+      previewTabsBySession: {
+        ...state.previewTabsBySession,
+        'session-code-selection': [{
+          id: 'file:src/App.ts',
+          path: 'src/App.ts',
+          kind: 'file',
+          title: 'App.ts',
+          language: 'text',
+          content: 'const title = "Todo"\nexport default title',
+          state: 'ok',
+          size: 42,
+        }],
+      },
+      activePreviewTabIdBySession: {
+        ...state.activePreviewTabIdBySession,
+        'session-code-selection': 'file:src/App.ts',
+      },
+    }))
+
+    const view = await renderPanel('session-code-selection')
+
+    await selectWorkspaceCodeText(view, 1, 'const title = "Todo"', 2, 'export default title')
+    const addButtons = view.getAllByRole('button', { name: 'Add to chat' })
+    await clickElement(addButtons[addButtons.length - 1]!)
+
+    expect(useWorkspaceChatContextStore.getState().referencesBySession['session-code-selection']).toMatchObject([
+      {
+        kind: 'code-selection',
+        path: 'src/App.ts',
+        absolutePath: '/repo/src/App.ts',
+        name: 'App.ts',
+        lineStart: 1,
+        lineEnd: 2,
+        quote: 'const title = "Todo"\nexport default title',
+      },
+    ])
+    expect(useWorkspaceChatContextStore.getState().referencesBySession['session-code-selection']?.[0]?.note).toBeUndefined()
+  })
+
+  it('keeps the selected-code action near the preview instead of the file tree', async () => {
+    await setWorkspaceState((state) => ({
+      ...state,
+      panelBySession: {
+        ...state.panelBySession,
+        'session-selection-position': {
+          isOpen: true,
+          activeView: 'all',
+        },
+      },
+      statusBySession: {
+        ...state.statusBySession,
+        'session-selection-position': {
+          state: 'ok',
+          workDir: '/repo',
+          repoName: 'repo',
+          branch: 'main',
+          isGitRepo: true,
+          changedFiles: [],
+        },
+      },
+      previewTabsBySession: {
+        ...state.previewTabsBySession,
+        'session-selection-position': [{
+          id: 'file:src/App.ts',
+          path: 'src/App.ts',
+          kind: 'file',
+          title: 'App.ts',
+          language: 'text',
+          content: 'const title = "Todo"\nexport default title',
+          state: 'ok',
+          size: 42,
+        }],
+      },
+      activePreviewTabIdBySession: {
+        ...state.activePreviewTabIdBySession,
+        'session-selection-position': 'file:src/App.ts',
+      },
+    }))
+
+    const view = await renderPanel('session-selection-position')
+
+    await selectWorkspaceCodeText(view, 1, 'const title = "Todo"', 1, 'const title = "Todo"')
+    const addButtons = view.getAllByRole('button', { name: 'Add to chat' })
+    const floatingAddButton = addButtons[addButtons.length - 1]!
+
+    expect(floatingAddButton.style.left).toBe('180px')
+    expect(floatingAddButton.style.top).toBe('80px')
+
+    fireEvent.keyDown(view.getByTestId('workspace-code').parentElement?.parentElement ?? view.getByTestId('workspace-code'), {
+      key: 'Escape',
+    })
+    await flushReactWork()
+    expect(view.queryAllByRole('button', { name: 'Add to chat' })).toHaveLength(1)
+  })
+
+  it('adds selected markdown text from a preview to the chat context', async () => {
+    await setWorkspaceState((state) => ({
+      ...state,
+      panelBySession: {
+        ...state.panelBySession,
+        'session-markdown-selection': {
+          isOpen: true,
+          activeView: 'all',
+        },
+      },
+      statusBySession: {
+        ...state.statusBySession,
+        'session-markdown-selection': {
+          state: 'ok',
+          workDir: '/repo',
+          repoName: 'repo',
+          branch: 'main',
+          isGitRepo: true,
+          changedFiles: [],
+        },
+      },
+      previewTabsBySession: {
+        ...state.previewTabsBySession,
+        'session-markdown-selection': [{
+          id: 'file:docs/guide.md',
+          path: 'docs/guide.md',
+          kind: 'file',
+          title: 'guide.md',
+          language: 'markdown',
+          content: '# Guide\nAlpha note and Beta note',
+          state: 'ok',
+          size: 33,
+        }],
+      },
+      activePreviewTabIdBySession: {
+        ...state.activePreviewTabIdBySession,
+        'session-markdown-selection': 'file:docs/guide.md',
+      },
+    }))
+
+    const view = await renderPanel('session-markdown-selection')
+    const paragraph = view.getByText('Alpha note and Beta note')
+    const markdownSurface = paragraph.closest('.min-h-0') ?? paragraph
+
+    await selectRenderedText(paragraph, 'Alpha note and Beta note', markdownSurface)
+    const addButtons = view.getAllByRole('button', { name: 'Add to chat' })
+    const floatingAddButton = addButtons[addButtons.length - 1]!
+    await clickElement(floatingAddButton)
+
+    expect(useWorkspaceChatContextStore.getState().referencesBySession['session-markdown-selection']).toMatchObject([
+      {
+        kind: 'code-selection',
+        path: 'docs/guide.md',
+        absolutePath: '/repo/docs/guide.md',
+        name: 'guide.md',
+        lineStart: 2,
+        lineEnd: 2,
+        quote: 'Alpha note and Beta note',
+      },
+    ])
+  })
+
  it('uses the localized view menu label', async () => {
    await setSettingsState({ ...settingsInitialState, locale: 'zh' })
    await setWorkspaceState((state) => ({
--- a/desktop/src/components/workspace/WorkspacePanel.tsx
+++ b/desktop/src/components/workspace/WorkspacePanel.tsx
@ -82,6 +82,7 @@ const FILE_STATUS_META: Record<WorkspaceFileStatus, { label: string; className:
 const EMPTY_TREE_BY_PATH: Record<string, WorkspaceTreeResult | undefined> = {}
 const EMPTY_PREVIEW_TABS: WorkspacePreviewTab[] = []
 const EMPTY_EXPANDED_PATHS: string[] = []
+const SELECTION_MENU_OFFSET = 8
 const FILE_BADGE_META: Record<string, { label: string; className: string }> = {
  ts: { label: 'TS', className: 'bg-[var(--color-secondary)]/14 text-[var(--color-secondary)]' },
  tsx: { label: 'TSX', className: 'bg-[var(--color-secondary)]/14 text-[var(--color-secondary)]' },
@ -207,6 +208,138 @@ function treeEntryMatchesFilter(
  return childTree.entries.some((child) => treeEntryMatchesFilter(child, query, treeByPath))
 }

+type WorkspaceTextSelection = {
+  text: string
+  startLine?: number
+  endLine?: number
+}
+
+type FloatingSelectionMenuState = WorkspaceTextSelection & {
+  x: number
+  y: number
+}
+
+type SelectionPointer = {
+  clientX: number
+  clientY: number
+}
+
+function getElementForNode(node: Node | null): Element | null {
+  if (!node) return null
+  return node.nodeType === Node.ELEMENT_NODE ? node as Element : node.parentElement
+}
+
+function getLineNumberFromNode(node: Node | null, root: HTMLElement) {
+  const element = getElementForNode(node)
+  const row = element?.closest('[data-workspace-line-number]')
+  if (!row || !root.contains(row)) return undefined
+  const line = Number(row.getAttribute('data-workspace-line-number'))
+  return Number.isFinite(line) ? line : undefined
+}
+
+function clampValue(value: number, min: number, max: number) {
+  return Math.max(min, Math.min(value, max))
+}
+
+function getSelectionPosition(range: Range, root: HTMLElement, pointer?: SelectionPointer) {
+  const rect = typeof range.getBoundingClientRect === 'function'
+    ? range.getBoundingClientRect()
+    : null
+  const rootRect = root.getBoundingClientRect()
+  const pointerInsideRoot = pointer
+    && pointer.clientX >= rootRect.left
+    && pointer.clientX <= rootRect.right
+    && pointer.clientY >= rootRect.top
+    && pointer.clientY <= rootRect.bottom
+  const fallbackX = rect && rect.width > 0
+    ? rect.left + rect.width / 2
+    : rect?.left ?? rootRect.left + 24
+  const fallbackY = rect
+    ? rect.bottom + SELECTION_MENU_OFFSET
+    : rootRect.top + 24
+  const unclampedX = pointerInsideRoot ? pointer.clientX : fallbackX
+  const unclampedY = pointerInsideRoot ? pointer.clientY + SELECTION_MENU_OFFSET : fallbackY
+  const minX = Math.max(12, rootRect.left + 8)
+  const maxX = Math.max(minX, Math.min(window.innerWidth - 160, rootRect.right - 136))
+  const minY = Math.max(12, rootRect.top + 8)
+  const maxY = Math.max(minY, Math.min(window.innerHeight - 48, rootRect.bottom - 40))
+
+  return {
+    x: clampValue(unclampedX, minX, maxX),
+    y: clampValue(unclampedY, minY, maxY),
+  }
+}
+
+function getTextSelectionFromContainer(
+  root: HTMLElement | null,
+  resolveLines?: (text: string, range: Range) => { startLine?: number; endLine?: number },
+  pointer?: SelectionPointer,
+): FloatingSelectionMenuState | null {
+  if (!root) return null
+
+  const selection = window.getSelection()
+  if (!selection || selection.isCollapsed || selection.rangeCount === 0) return null
+
+  const range = selection.getRangeAt(0)
+  const startElement = getElementForNode(range.startContainer)
+  const endElement = getElementForNode(range.endContainer)
+  if (!startElement || !endElement || !root.contains(startElement) || !root.contains(endElement)) {
+    return null
+  }
+
+  const text = selection.toString().trim()
+  if (!text) return null
+
+  const nodeLines = {
+    startLine: getLineNumberFromNode(range.startContainer, root),
+    endLine: getLineNumberFromNode(range.endContainer, root),
+  }
+  const resolvedLines = resolveLines?.(text, range) ?? nodeLines
+  const startLine = resolvedLines.startLine ?? nodeLines.startLine
+  const endLine = resolvedLines.endLine ?? nodeLines.endLine ?? startLine
+  const orderedStart = startLine && endLine ? Math.min(startLine, endLine) : startLine
+  const orderedEnd = startLine && endLine ? Math.max(startLine, endLine) : endLine
+
+  return {
+    ...getSelectionPosition(range, root, pointer),
+    text,
+    ...(orderedStart ? { startLine: orderedStart } : {}),
+    ...(orderedEnd ? { endLine: orderedEnd } : {}),
+  }
+}
+
+function getLineRangeForText(value: string, text: string) {
+  const index = value.indexOf(text)
+  if (index < 0) return {}
+  const startLine = value.slice(0, index).split('\n').length
+  const endLine = startLine + text.split('\n').length - 1
+  return { startLine, endLine }
+}
+
+function FloatingSelectionMenu({
+  selection,
+  onAdd,
+}: {
+  selection: FloatingSelectionMenuState | null
+  onAdd: () => void
+}) {
+  const t = useTranslation()
+  if (!selection) return null
+
+  return (
+    <button
+      type="button"
+      onMouseDown={(event) => event.preventDefault()}
+      onClick={onAdd}
+      className="fixed z-50 inline-flex h-8 items-center gap-1.5 rounded-[8px] border border-[var(--color-border)] bg-[var(--color-surface-container-lowest)] px-2.5 text-[12px] font-medium text-[var(--color-text-primary)] shadow-[var(--shadow-dropdown)] transition-colors hover:bg-[var(--color-surface-hover)] focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-[var(--color-brand)]/35"
+      style={{ left: selection.x, top: selection.y }}
+    >
+      <span aria-hidden="true" className="material-symbols-outlined text-[15px] text-[var(--color-text-tertiary)]">person_add</span>
+      <span>{t('workspace.addSelectionToChat')}</span>
+    </button>
+  )
+}
+
 function PanelMessage({
  icon,
  message,
@ -308,15 +441,19 @@ function CodeSurface({
  value,
  language,
  onAddLineComment,
+  onAddSelection,
 }: {
  value: string
  language: string
  onAddLineComment: (line: number, note: string, quote: string) => void
+  onAddSelection: (selection: WorkspaceTextSelection) => void
 }) {
  const t = useTranslation()
+  const surfaceRef = useRef<HTMLDivElement>(null)
  const [commentLine, setCommentLine] = useState<number | null>(null)
  const [commentDraft, setCommentDraft] = useState('')
  const [showAllLines, setShowAllLines] = useState(false)
+  const [selectionMenu, setSelectionMenu] = useState<FloatingSelectionMenuState | null>(null)
  const lines = value.split('\n')
  const visibleLines = showAllLines ? lines : lines.slice(0, WORKSPACE_PREVIEW_LINE_LIMIT)
  const activeQuote = commentLine ? visibleLines[commentLine - 1] ?? '' : ''
@ -327,6 +464,7 @@ function CodeSurface({
    setShowAllLines(false)
    setCommentLine(null)
    setCommentDraft('')
+    setSelectionMenu(null)
  }, [language, value])

  const submitLineComment = () => {
@ -336,6 +474,30 @@ function CodeSurface({
    setCommentDraft('')
  }

+  const handleSelectionMouseUp = (event: MouseEvent<HTMLDivElement>) => {
+    const selection = getTextSelectionFromContainer(surfaceRef.current, undefined, event)
+    if (!selection?.startLine || !selection.endLine || selection.startLine === selection.endLine) {
+      setSelectionMenu(selection)
+      return
+    }
+
+    setSelectionMenu({
+      ...selection,
+      text: visibleLines.slice(selection.startLine - 1, selection.endLine).join('\n').trim(),
+    })
+  }
+
+  const addCurrentSelectionToChat = () => {
+    if (!selectionMenu) return
+    onAddSelection({
+      text: selectionMenu.text,
+      startLine: selectionMenu.startLine,
+      endLine: selectionMenu.endLine,
+    })
+    setSelectionMenu(null)
+    window.getSelection()?.removeAllRanges()
+  }
+
  const renderLineCommentEditor = (lineNumber: number) => {
    if (commentLine !== lineNumber) return null

@ -398,7 +560,14 @@ function CodeSurface({
  )

  return (
-    <div className="min-h-0 flex-1 overflow-auto bg-[var(--color-code-bg)]">
+    <div
+      ref={surfaceRef}
+      className="min-h-0 flex-1 overflow-auto bg-[var(--color-code-bg)]"
+      onMouseUp={handleSelectionMouseUp}
+      onKeyDown={(event) => {
+        if (event.key === 'Escape') setSelectionMenu(null)
+      }}
+    >
      <div className="relative min-w-max py-2">
        {usePlainLargePreview ? (
          <pre
@ -411,7 +580,10 @@ function CodeSurface({
              const lineNumber = index + 1
              return (
                <div key={lineNumber}>
-                  <div className="group grid grid-cols-[48px_minmax(0,1fr)] gap-3 px-3 hover:bg-[var(--color-surface-hover)]">
+                  <div
+                    className="group grid grid-cols-[48px_minmax(0,1fr)] gap-3 px-3 hover:bg-[var(--color-surface-hover)]"
+                    data-workspace-line-number={lineNumber}
+                  >
                    {renderLineNumberButton(lineNumber)}
                    <span className="whitespace-pre pr-6">{line || ' '}</span>
                  </div>
@ -440,6 +612,7 @@ function CodeSurface({
                    <div key={String(lineKey)}>
                      <div
                        {...lineProps}
+                        data-workspace-line-number={lineNumber}
                        className="group grid grid-cols-[48px_minmax(0,1fr)] gap-3 px-3 hover:bg-[var(--color-surface-hover)]"
                      >
                        {renderLineNumberButton(lineNumber)}
@ -475,13 +648,53 @@ function CodeSurface({
          </div>
        )}
      </div>
+      <FloatingSelectionMenu selection={selectionMenu} onAdd={addCurrentSelectionToChat} />
    </div>
  )
 }

-function MarkdownSurface({ value }: { value: string }) {
+function MarkdownSurface({
+  value,
+  onAddSelection,
+}: {
+  value: string
+  onAddSelection: (selection: WorkspaceTextSelection) => void
+}) {
+  const surfaceRef = useRef<HTMLDivElement>(null)
+  const [selectionMenu, setSelectionMenu] = useState<FloatingSelectionMenuState | null>(null)
+
+  useEffect(() => {
+    setSelectionMenu(null)
+  }, [value])
+
+  const handleSelectionMouseUp = (event: MouseEvent<HTMLDivElement>) => {
+    setSelectionMenu(getTextSelectionFromContainer(
+      surfaceRef.current,
+      (text) => getLineRangeForText(value, text),
+      event,
+    ))
+  }
+
+  const addCurrentSelectionToChat = () => {
+    if (!selectionMenu) return
+    onAddSelection({
+      text: selectionMenu.text,
+      startLine: selectionMenu.startLine,
+      endLine: selectionMenu.endLine,
+    })
+    setSelectionMenu(null)
+    window.getSelection()?.removeAllRanges()
+  }
+
  return (
-    <div className="min-h-0 flex-1 overflow-auto bg-[var(--color-surface)]">
+    <div
+      ref={surfaceRef}
+      className="min-h-0 flex-1 overflow-auto bg-[var(--color-surface)]"
+      onMouseUp={handleSelectionMouseUp}
+      onKeyDown={(event) => {
+        if (event.key === 'Escape') setSelectionMenu(null)
+      }}
+    >
      <div className="mx-auto w-full max-w-[860px] px-6 py-5">
        <MarkdownRenderer
          content={value}
@ -489,6 +702,7 @@ function MarkdownSurface({ value }: { value: string }) {
          className="workspace-markdown-preview prose-p:text-[14px] prose-p:leading-7 prose-h1:text-[24px] prose-h2:text-[18px] prose-h3:text-[15px] prose-code:text-[12px] prose-pre:my-4"
        />
      </div>
+      <FloatingSelectionMenu selection={selectionMenu} onAdd={addCurrentSelectionToChat} />
    </div>
  )
 }
@ -815,6 +1029,18 @@ export function WorkspacePanel({ sessionId }: WorkspacePanelProps) {
    })
  }

+  const addSelectionToChat = (path: string, selection: WorkspaceTextSelection) => {
+    addWorkspaceReference(sessionId, {
+      kind: 'code-selection',
+      path,
+      absolutePath: resolveWorkspaceAttachmentPath(status?.workDir, path),
+      name: path.split('/').pop() || path,
+      lineStart: selection.startLine,
+      lineEnd: selection.endLine,
+      quote: selection.text,
+    })
+  }
+
  const handleSetActiveView = (view: 'changed' | 'all') => {
    setActiveView(sessionId, view)
    setIsViewMenuOpen(false)
@ -996,12 +1222,16 @@ export function WorkspacePanel({ sessionId }: WorkspacePanelProps) {
            path={activePreviewTab.path}
          />
        ) : state === 'ok' && isMarkdownPreview(activePreviewTab) ? (
-          <MarkdownSurface value={activePreviewTab.content ?? ''} />
+          <MarkdownSurface
+            value={activePreviewTab.content ?? ''}
+            onAddSelection={(selection) => addSelectionToChat(activePreviewTab.path, selection)}
+          />
        ) : state === 'ok' ? (
          <CodeSurface
            value={activePreviewTab.content ?? ''}
            language={activePreviewTab.language ?? 'text'}
            onAddLineComment={(line, note, quote) => addLineCommentToChat(activePreviewTab.path, line, note, quote)}
+            onAddSelection={(selection) => addSelectionToChat(activePreviewTab.path, selection)}
          />
        ) : (
          <PanelMessage
--- a/desktop/src/i18n/locales/en.ts
+++ b/desktop/src/i18n/locales/en.ts
@ -85,6 +85,7 @@ export const en = {
  'workspace.showAllLoadedLines': 'Show all loaded lines',
  'workspace.collapsePreview': 'Collapse preview',
  'workspace.addToChat': 'Add to chat',
+  'workspace.addSelectionToChat': 'Add to chat',
  'workspace.copyPath': 'Copy path',
  'workspace.localComment': 'Local comment',
  'workspace.commentLine': 'Comment line {line}',
@ -806,6 +807,10 @@ export const en = {
  '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.contextReferencesOnly': 'Added {count} references',
+  'chat.addSelectionToChat': 'Add to chat',
+  'chat.userMessageReference': 'User message',
+  'chat.assistantMessageReference': 'Assistant message',
  'chat.slashCommands': 'Slash commands',
  'slash.mcp.title': 'Available MCP tools',
  'slash.mcp.subtitle': 'Global and current-project MCP servers available in this chat context.',
--- a/desktop/src/i18n/locales/zh.ts
+++ b/desktop/src/i18n/locales/zh.ts
@ -87,6 +87,7 @@ export const zh: Record<TranslationKey, string> = {
  'workspace.showAllLoadedLines': '显示全部已加载行',
  'workspace.collapsePreview': '收起预览',
  'workspace.addToChat': '添加到聊天',
+  'workspace.addSelectionToChat': '添加至对话',
  'workspace.copyPath': '复制路径',
  'workspace.localComment': '本地评论',
  'workspace.commentLine': '评论第 {line} 行',
@ -808,6 +809,10 @@ export const zh: Record<TranslationKey, string> = {
  '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.contextReferencesOnly': '已添加 {count} 个引用',
+  'chat.addSelectionToChat': '添加至对话',
+  'chat.userMessageReference': '用户消息',
+  'chat.assistantMessageReference': 'AI 回复',
  '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。',
--- a/desktop/src/stores/chatStore.test.ts
+++ b/desktop/src/stores/chatStore.test.ts
@ -449,7 +449,7 @@ describe('chatStore history mapping', () => {

    useChatStore.getState().sendMessage(
      TEST_SESSION_ID,
-      'Notes for attached workspace files:\n- src/App.tsx:L4\n  Comment: tighten this',
+      'Referenced workspace context:\n@"src/App.tsx:L4":\nComment: tighten this\n```tsx\nconst value = 1\n```',
      [{
        type: 'file',
        name: 'App.tsx',
@ -477,7 +477,7 @@ describe('chatStore history mapping', () => {
      {
        type: 'user_text',
        content: '改这里',
-        modelContent: '@"/repo/src/App.tsx" Notes for attached workspace files:\n- src/App.tsx:L4\n  Comment: tighten this',
+        modelContent: '@"/repo/src/App.tsx" Referenced workspace context:\n@"src/App.tsx:L4":\nComment: tighten this\n```tsx\nconst value = 1\n```',
        attachments: [{
          type: 'file',
          name: 'App.tsx',
@ -493,7 +493,7 @@ describe('chatStore history mapping', () => {
      TEST_SESSION_ID,
      {
        type: 'user_message',
-        content: 'Notes for attached workspace files:\n- src/App.tsx:L4\n  Comment: tighten this',
+        content: 'Referenced workspace context:\n@"src/App.tsx:L4":\nComment: tighten this\n```tsx\nconst value = 1\n```',
        attachments: [{
          type: 'file',
          name: 'App.tsx',
--- a/desktop/src/stores/workspaceChatContextStore.test.ts
+++ b/desktop/src/stores/workspaceChatContextStore.test.ts
@ -45,14 +45,54 @@ describe('workspaceChatContextStore', () => {
      },
    ])

-    expect(prompt).toContain('Notes for attached workspace files:')
-    expect(prompt).toContain('- src/App.tsx:L12')
+    expect(prompt).toContain('Referenced workspace context:')
+    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).toContain('```tsx\nconst value = 1\n```')
    expect(prompt).not.toContain('Use the Read tool')
    expect(prompt).not.toContain('Path: /repo/src/App.tsx')
  })

+  it('formats selected code without requiring a comment', () => {
+    const prompt = formatWorkspaceReferencePrompt([
+      {
+        id: 'ref-1',
+        kind: 'code-selection',
+        path: 'src/App.tsx',
+        absolutePath: '/repo/src/App.tsx',
+        name: 'App.tsx',
+        lineStart: 10,
+        lineEnd: 12,
+        quote: 'const value = 1\nreturn value',
+      },
+    ])
+
+    expect(prompt).toContain('Referenced workspace context:')
+    expect(prompt).toContain('@"src/App.tsx:L10-L12":')
+    expect(prompt).toContain('```tsx\nconst value = 1\nreturn value\n```')
+    expect(prompt).not.toContain('Comment:')
+  })
+
+  it('formats selected chat messages as chat context instead of file context', () => {
+    const prompt = formatWorkspaceReferencePrompt([
+      {
+        id: 'chat-ref-1',
+        kind: 'chat-selection',
+        path: 'chat://assistant/assistant-1',
+        name: 'Assistant message',
+        messageId: 'assistant-1',
+        sourceRole: 'assistant',
+        quote: 'Use the workspace panel selection menu.',
+      },
+    ])
+
+    expect(prompt).toContain('Referenced chat context:')
+    expect(prompt).toContain('Assistant message:')
+    expect(prompt).toContain('```\nUse the workspace panel selection menu.\n```')
+    expect(prompt).not.toContain('@"chat://assistant/assistant-1"')
+    expect(prompt).not.toContain('Referenced workspace context:')
+  })
+
  it('does not add prompt text for plain file attachments', () => {
    const prompt = formatWorkspaceReferencePrompt([
      {
--- a/desktop/src/stores/workspaceChatContextStore.ts
+++ b/desktop/src/stores/workspaceChatContextStore.ts
@ -1,6 +1,6 @@
 import { create } from 'zustand'

-export type WorkspaceChatReferenceKind = 'file' | 'code-comment'
+export type WorkspaceChatReferenceKind = 'file' | 'code-comment' | 'code-selection' | 'chat-selection'

 export type WorkspaceChatReference = {
  id: string
@ -13,6 +13,8 @@ export type WorkspaceChatReference = {
  lineEnd?: number
  note?: string
  quote?: string
+  sourceRole?: 'user' | 'assistant'
+  messageId?: string
 }

 type WorkspaceChatContextStore = {
@ -29,17 +31,29 @@ type WorkspaceChatContextStore = {
 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) : ''
+    : reference.messageId ?? 'file'
+  const notePart = (reference.note?.trim() || reference.quote?.trim() || '').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 ?? ''}`
+  return [
+    reference.kind,
+    reference.path,
+    reference.messageId ?? '',
+    reference.sourceRole ?? '',
+    reference.lineStart ?? '',
+    reference.lineEnd ?? '',
+    reference.note?.trim() ?? '',
+    reference.quote?.trim() ?? '',
+  ].join(':')
 }

 export function formatWorkspaceReferenceLocation(reference: WorkspaceChatReference) {
+  if (reference.kind === 'chat-selection') {
+    return reference.sourceRole === 'assistant' ? 'Assistant message' : 'User message'
+  }
  if (!reference.lineStart) return reference.path
  const lineEnd = reference.lineEnd && reference.lineEnd !== reference.lineStart
    ? `-L${reference.lineEnd}`
@ -47,27 +61,79 @@ export function formatWorkspaceReferenceLocation(reference: WorkspaceChatReferen
  return `${reference.path}:L${reference.lineStart}${lineEnd}`
 }

+function getFenceForQuote(quote: string) {
+  const runs = quote.match(/`+/g) ?? []
+  const longestRun = runs.reduce((max, run) => Math.max(max, run.length), 0)
+  return '`'.repeat(Math.max(3, longestRun + 1))
+}
+
+function getLanguageHint(reference: WorkspaceChatReference) {
+  if (reference.kind === 'chat-selection') return ''
+  const extension = reference.name.split('.').pop()?.toLowerCase()
+  if (!extension || extension === reference.name.toLowerCase()) return ''
+  const aliases: Record<string, string> = {
+    js: 'javascript',
+    jsx: 'jsx',
+    ts: 'typescript',
+    tsx: 'tsx',
+    md: 'markdown',
+    py: 'python',
+    rb: 'ruby',
+    rs: 'rust',
+    sh: 'bash',
+    yml: 'yaml',
+  }
+  return aliases[extension] ?? extension
+}
+
 export function formatWorkspaceReferencePrompt(references: WorkspaceChatReference[]) {
-  const referencesWithContext = references.filter((reference) =>
+  const workspaceReferencesWithContext = references.filter((reference) =>
    reference.kind === 'code-comment' ||
+    reference.kind === 'code-selection' ||
    !!reference.lineStart ||
    !!reference.note?.trim() ||
    !!reference.quote?.trim(),
+  ).filter((reference) => reference.kind !== 'chat-selection')
+  const chatReferencesWithContext = references.filter((reference) =>
+    reference.kind === 'chat-selection' && !!reference.quote?.trim(),
  )
-  if (referencesWithContext.length === 0) return ''
+  if (workspaceReferencesWithContext.length === 0 && chatReferencesWithContext.length === 0) return ''

-  const lines = [
-    'Notes for attached workspace files:',
-    ...referencesWithContext.map((reference) => {
+  const workspaceLines = workspaceReferencesWithContext.length > 0
+    ? [
+        'Referenced workspace context:',
+        ...workspaceReferencesWithContext.map((reference) => {
+          const location = formatWorkspaceReferenceLocation(reference)
+          const parts = [`@"${location}":`]
+          if (reference.note?.trim()) parts.push(`Comment: ${reference.note.trim()}`)
+          if (reference.quote?.trim()) {
+            const fence = getFenceForQuote(reference.quote)
+            const languageHint = getLanguageHint(reference)
+            parts.push(`${fence}${languageHint}`)
+            parts.push(reference.quote.trim())
+            parts.push(fence)
+          }
+          return parts.join('\n')
+        }),
+      ]
+    : []
+  const chatLines = chatReferencesWithContext.length > 0
+    ? [
+        'Referenced chat context:',
+        ...chatReferencesWithContext.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: ${reference.quote.trim()}`)
-      return parts.join('\n  ')
-    }),
-  ]
+          const fence = getFenceForQuote(reference.quote ?? '')
+          return [
+            `${location}:`,
+            fence,
+            reference.quote?.trim() ?? '',
+            fence,
+          ].join('\n')
+        }),
+      ]
+    : []

-  return lines.join('\n')
+  return [...workspaceLines, ...chatLines].join('\n')
 }

 export const useWorkspaceChatContextStore = create<WorkspaceChatContextStore>((set) => ({