Inspired by ChatGPT Work: convert large pastes into .txt attachments in the Desktop composer

Pasting more than 10k characters of plain text into the Desktop composer
now converts the content into a 'Pasted content (NN KB)' .txt attachment
chip instead of flooding the input, mirroring ChatGPT's large-paste
handling (OpenAI release notes, Aug 4 2026). Short pastes stay inline;
the exact text is preserved byte-for-byte in a Hermes-managed
composer-pastes file and rides the existing @file: attachment pipeline.
If the desktop bridge is missing or the write fails, the paste falls
back to inline insertion so nothing is ever lost.

Implements #66622.

apps/desktop/electron/main.ts

@@ -4863,6 +4863,20 @@ async function writeComposerImage(buffer, ext = '.png') {
   return filePath
 }
 
+// Large plain-text pastes are persisted as .txt files so the composer can
+// show them as an attachment chip instead of flooding the input (ChatGPT
+// Work-style large-paste handling). Mirrors writeComposerImage above.
+async function writeComposerPaste(text) {
+  const dir = path.join(app.getPath('userData'), 'composer-pastes')
+  await fs.promises.mkdir(dir, { recursive: true })
+  const stamp = new Date().toISOString().replace(/[:.]/g, '-').replace('T', '_').replace('Z', '')
+  const random = crypto.randomBytes(3).toString('hex')
+  const filePath = path.join(dir, `pasted_content_${stamp}_${random}.txt`)
+  await fs.promises.writeFile(filePath, text, 'utf8')
+
+  return filePath
+}
+
 function previewLabelForUrl(url) {
   return `${url.host}${url.pathname === '/' ? '' : url.pathname}`
 }
@@ -10549,6 +10563,16 @@ ipcMain.handle('hermes:saveImageBuffer', async (_event, payload) => {
   return writeComposerImage(buffer, payload?.ext || '.png')
 })
 
+ipcMain.handle('hermes:savePastedText', async (_event, payload) => {
+  const text = typeof payload?.text === 'string' ? payload.text : ''
+
+  if (!text) {
+    throw new Error('savePastedText: missing text')
+  }
+
+  return writeComposerPaste(text)
+})
+
 ipcMain.handle('hermes:saveClipboardImage', async () => {
   const image = clipboard.readImage()
 

apps/desktop/electron/preload.ts

@@ -120,6 +120,7 @@ contextBridge.exposeInMainWorld('hermesDesktop', {
   readClipboard: () => ipcRenderer.invoke('hermes:readClipboard'),
   saveImageFromUrl: url => ipcRenderer.invoke('hermes:saveImageFromUrl', url),
   saveImageBuffer: (data, ext) => ipcRenderer.invoke('hermes:saveImageBuffer', { data, ext }),
+  savePastedText: text => ipcRenderer.invoke('hermes:savePastedText', { text }),
   saveClipboardImage: () => ipcRenderer.invoke('hermes:saveClipboardImage'),
   getPathForFile: file => {
     try {

apps/desktop/src/app/chat/composer/index.tsx

@@ -54,6 +54,7 @@ import { useEmojiCompletions } from './hooks/use-emoji-completions'
 import { useComposerMicroActions } from './hooks/use-micro-actions'
 import { useSlashCompletions } from './hooks/use-slash-completions'
 import { useSessionStatusPresence } from './hooks/use-status-presence'
+import { shouldConvertPasteToAttachment } from './large-paste'
 import { ActionBadges } from './micro-actions'
 import { chipTypedPathOnSpace, pathifyRefs } from './path-refs'
 import { QueuePanel } from './queue-panel'
@@ -91,6 +92,7 @@ export function ChatBar({
   onAddUrl,
   onAttachDroppedItems,
   onAttachImageBlob,
+  onAttachPastedText,
   onPasteClipboardImage,
   onPickFiles,
   onPickFolders,
@@ -488,6 +490,30 @@ export function ChatBar({
 
     event.preventDefault()
 
+    // ChatGPT Work-style large-paste handling: a paste past the threshold
+    // becomes a `.txt` attachment chip instead of flooding the composer.
+    // The instruction the user types stays in the input; the pasted source
+    // material rides along as a file. Falls back to inline insertion if the
+    // attachment can't be created (missing bridge, write failure) so the
+    // paste is never lost.
+    if (onAttachPastedText && shouldConvertPasteToAttachment(pastedText)) {
+      const editor = event.currentTarget
+
+      void Promise.resolve(onAttachPastedText(pastedText)).then(attached => {
+        if (attached) {
+          triggerHaptic('selection')
+
+          return
+        }
+
+        recordUndoPoint()
+        insertComposerContentsAtCaret(editor, pathifyRefs(linkifyUrls(pastedText)), openDirectiveScope(editor))
+        scheduleFlushEditorToDraft(editor)
+      })
+
+      return
+    }
+
     // Links in the paste land as `@url:` chips rather than a wall of URL text —
     // the same reference the "Add URL" dialog inserts, parsed in place so a link
     // mid-sentence keeps its position. Bare `@path` tokens promote the same way.

apps/desktop/src/app/chat/composer/large-paste.test.ts

@@ -0,0 +1,33 @@
+import { describe, expect, it } from 'vitest'
+
+import { LARGE_PASTE_ATTACHMENT_THRESHOLD, shouldConvertPasteToAttachment } from './large-paste'
+
+describe('shouldConvertPasteToAttachment', () => {
+  it('keeps short pastes inline', () => {
+    expect(shouldConvertPasteToAttachment('hello world')).toBe(false)
+    expect(shouldConvertPasteToAttachment('')).toBe(false)
+  })
+
+  it('keeps a paste exactly at the threshold inline', () => {
+    expect(shouldConvertPasteToAttachment('a'.repeat(LARGE_PASTE_ATTACHMENT_THRESHOLD))).toBe(false)
+  })
+
+  it('converts a paste one character past the threshold', () => {
+    expect(shouldConvertPasteToAttachment('a'.repeat(LARGE_PASTE_ATTACHMENT_THRESHOLD + 1))).toBe(true)
+  })
+
+  it('honors a custom threshold', () => {
+    expect(shouldConvertPasteToAttachment('abcdef', 5)).toBe(true)
+    expect(shouldConvertPasteToAttachment('abcde', 5)).toBe(false)
+  })
+
+  it('never converts when the threshold is disabled (non-positive)', () => {
+    expect(shouldConvertPasteToAttachment('a'.repeat(50_000), 0)).toBe(false)
+    expect(shouldConvertPasteToAttachment('a'.repeat(50_000), -1)).toBe(false)
+  })
+
+  it('rejects non-string input defensively', () => {
+    expect(shouldConvertPasteToAttachment(undefined as unknown as string)).toBe(false)
+    expect(shouldConvertPasteToAttachment(null as unknown as string)).toBe(false)
+  })
+})

apps/desktop/src/app/chat/composer/large-paste.ts

@@ -0,0 +1,40 @@
+/**
+ * Large-paste-to-attachment policy.
+ *
+ * Inspired by ChatGPT Work's composer behavior (OpenAI release notes,
+ * Aug 4 2026): pasting more than ~10k characters converts the content into a
+ * text attachment instead of inserting it inline, keeping the composer clean
+ * and preventing a single paste from flooding the input. Short pastes stay
+ * inline; the threshold lives here so every paste handler shares one policy.
+ */
+
+/** Characters beyond which a plain-text paste becomes a `.txt` attachment. */
+export const LARGE_PASTE_ATTACHMENT_THRESHOLD = 10_000
+
+/**
+ * True when a plain-text paste should be converted into a text attachment
+ * rather than inserted inline. Only sheer size qualifies — rich clipboard
+ * data, images, and files never route through this path (they have their own
+ * pipelines upstream of this check).
+ */
+export function shouldConvertPasteToAttachment(
+  text: string,
+  threshold: number = LARGE_PASTE_ATTACHMENT_THRESHOLD
+): boolean {
+  return typeof text === 'string' && threshold > 0 && text.length > threshold
+}
+
+/** Human-readable size of a paste's UTF-8 bytes, for the attachment chip. */
+export function pasteSizeLabel(text: string): string {
+  const bytes = new TextEncoder().encode(text).length
+
+  if (bytes < 1024) {
+    return `${bytes} B`
+  }
+
+  if (bytes < 1024 * 1024) {
+    return `${(bytes / 1024).toFixed(1)} KB`
+  }
+
+  return `${(bytes / (1024 * 1024)).toFixed(1)} MB`
+}

apps/desktop/src/app/chat/composer/types.ts

@@ -46,6 +46,7 @@ export interface ChatBarProps {
   onAddUrl?: (url: string) => void
   onAttachImageBlob?: (blob: Blob) => Promise<boolean | void> | boolean | void
   onAttachDroppedItems?: (candidates: DroppedFile[]) => Promise<boolean | void> | boolean | void
+  onAttachPastedText?: (text: string) => Promise<boolean> | boolean
   onPasteClipboardImage?: (opts?: { silent?: boolean }) => Promise<boolean> | void
   onPickFiles?: () => void
   onPickFolders?: () => void

apps/desktop/src/app/chat/hooks/use-composer-actions.ts

@@ -2,6 +2,7 @@ import { useCallback } from 'react'
 
 import { requestComposerFocus, requestComposerInsert, requestComposerInsertRefs } from '@/app/chat/composer/focus'
 import { droppedFileInlineRef } from '@/app/chat/composer/inline-refs'
+import { pasteSizeLabel } from '@/app/chat/composer/large-paste'
 import { formatRefValue } from '@/components/assistant-ui/directive-text'
 import { useI18n } from '@/i18n'
 import { attachmentId, contextPath, pathLabel } from '@/lib/chat-runtime'
@@ -517,6 +518,48 @@ export function useComposerActions({
     [attachImagePath, copy.clipboard, copy.clipboardPasteFailed, copy.noClipboardImage]
   )
 
+  /**
+   * Convert a very large plain-text paste into a `.txt` attachment chip
+   * (ChatGPT Work-style). The exact pasted text is written to a
+   * Hermes-managed composer-pastes file via the main process, then attached
+   * through the same `@file:` pipeline as a manually attached text file.
+   * Returns false (paste stays inline) when the desktop bridge is missing
+   * or the write fails.
+   */
+  const attachPastedText = useCallback(
+    async (text: string) => {
+      const save = window.hermesDesktop?.savePastedText
+
+      if (!text || !save) {
+        return false
+      }
+
+      try {
+        const savedPath = await save(text)
+
+        if (!savedPath) {
+          return false
+        }
+
+        attachToMain({
+          id: attachmentId('file', savedPath),
+          kind: 'file',
+          label: `${copy.pastedContent} (${pasteSizeLabel(text)})`,
+          detail: contextPath(savedPath, currentCwd),
+          refText: `@file:${formatRefValue(savedPath)}`,
+          path: savedPath
+        })
+
+        return true
+      } catch (err) {
+        notifyError(err, copy.pasteAttachFailed)
+
+        return false
+      }
+    },
+    [attachToMain, copy.pasteAttachFailed, copy.pastedContent, currentCwd]
+  )
+
   const attachContextFolderPath = useCallback(
     (folderPath: string) => {
       if (!folderPath) {
@@ -653,6 +696,7 @@ export function useComposerActions({
     attachDroppedItems,
     attachImageBlob,
     attachImagePath,
+    attachPastedText,
     insertContextPathInlineRef,
     pasteClipboardImage,
     pickContextPaths,

apps/desktop/src/app/chat/index.tsx

@@ -78,6 +78,7 @@ interface ChatViewProps extends Omit<React.ComponentProps<'div'>, 'onSubmit'> {
   maxVoiceRecordingSeconds?: number
   onAttachImageBlob: (blob: Blob) => Promise<boolean | void> | boolean | void
   onAttachDroppedItems: (candidates: DroppedFile[]) => Promise<boolean | void> | boolean | void
+  onAttachPastedText?: (text: string) => Promise<boolean> | boolean
   onPasteClipboardImage: (opts?: { silent?: boolean }) => Promise<boolean> | void
   onPickFiles: () => void
   onPickFolders: () => void
@@ -282,6 +283,7 @@ export const ChatView = memo(function ChatView({
   onAddUrl,
   onAttachImageBlob,
   onAttachDroppedItems,
+  onAttachPastedText,
   onBranchInNewChat,
   maxVoiceRecordingSeconds,
   onPasteClipboardImage,
@@ -609,6 +611,7 @@ export const ChatView = memo(function ChatView({
               onAddUrl={onAddUrl}
               onAttachDroppedItems={onAttachDroppedItems}
               onAttachImageBlob={onAttachImageBlob}
+              onAttachPastedText={onAttachPastedText}
               onCancel={onCancel}
               onPasteClipboardImage={onPasteClipboardImage}
               onPickFiles={onPickFiles}

apps/desktop/src/app/chat/session-tile.tsx

@@ -199,6 +199,7 @@ function TileChat({
           onAddUrl={onAddUrl}
           onAttachDroppedItems={composer.attachDroppedItems}
           onAttachImageBlob={composer.attachImageBlob}
+          onAttachPastedText={composer.attachPastedText}
           onCancel={actions.cancelRun}
           onDeleteSelectedSession={noop}
           onDismissError={actions.dismissError}

apps/desktop/src/app/contrib/types.ts

@@ -32,6 +32,7 @@ export type ChatActions = Pick<
   | 'onAddUrl'
   | 'onAttachDroppedItems'
   | 'onAttachImageBlob'
+  | 'onAttachPastedText'
   | 'onBranchInNewChat'
   | 'onCancel'
   | 'onDeleteSelectedSession'

apps/desktop/src/app/contrib/wiring.tsx

@@ -861,6 +861,7 @@ export function ContribWiring({ children }: { children: ReactNode }) {
     onArchiveSession: sessionId => void archiveSession(sessionId),
     onAttachDroppedItems: composer.attachDroppedItems,
     onAttachImageBlob: composer.attachImageBlob,
+    onAttachPastedText: composer.attachPastedText,
     onBranchInNewChat: messageId => void branchInNewChat(messageId),
     onBranchSession: sessionId => void branchStoredSession(sessionId),
     onCancel: cancelRun,

apps/desktop/src/global.d.ts

@@ -139,6 +139,7 @@ declare global {
       readClipboard: () => Promise<string>
       saveImageFromUrl: (url: string) => Promise<boolean>
       saveImageBuffer: (data: ArrayBuffer | Uint8Array, ext: string) => Promise<string>
+      savePastedText: (text: string) => Promise<string>
       saveClipboardImage: () => Promise<string>
       getPathForFile: (file: File) => string
       normalizePreviewTarget: (target: string, baseDir?: string) => Promise<HermesPreviewTarget | null>

apps/desktop/src/i18n/ar.ts

@@ -2571,6 +2571,8 @@ export const ar = defineLocale({
     imageAttach: 'إرفاق الصورة',
     imageWriteFailed: 'فشل كتابة الصورة',
     imageAttachFailed: 'فشل إرفاق الصورة',
+    pastedContent: 'محتوى ملصق',
+    pasteAttachFailed: 'تعذر إرفاق النص الملصق',
     attachImages: 'إرفاق الصور',
     clipboard: 'الحافظة',
     noClipboardImage: 'لا توجد صورة في الحافظة',

apps/desktop/src/i18n/en.ts

@@ -2942,6 +2942,8 @@ export const en: Translations = {
     imageAttach: 'Image attach',
     imageWriteFailed: 'Failed to write image to disk.',
     imageAttachFailed: 'Image attach failed',
+    pastedContent: 'Pasted content',
+    pasteAttachFailed: 'Could not attach pasted text',
     attachImages: 'Attach images',
     clipboard: 'Clipboard',
     noClipboardImage: 'No image found in clipboard',

apps/desktop/src/i18n/ja.ts

@@ -2782,6 +2782,8 @@ export const ja = defineLocale({
     imageAttach: '画像を添付',
     imageWriteFailed: '画像のディスクへの書き込みに失敗しました。',
     imageAttachFailed: '画像の添付に失敗しました',
+    pastedContent: '貼り付けた内容',
+    pasteAttachFailed: '貼り付けたテキストを添付できませんでした',
     attachImages: '画像を添付',
     clipboard: 'クリップボード',
     noClipboardImage: 'クリップボードに画像が見つかりません',

apps/desktop/src/i18n/types.ts

@@ -2495,6 +2495,8 @@ export interface Translations {
     imageAttach: string
     imageWriteFailed: string
     imageAttachFailed: string
+    pastedContent: string
+    pasteAttachFailed: string
     attachImages: string
     clipboard: string
     noClipboardImage: string

apps/desktop/src/i18n/zh-hant.ts

@@ -2668,6 +2668,8 @@ export const zhHant = defineLocale({
     imageAttach: '附加圖片',
     imageWriteFailed: '無法將圖片寫入磁碟。',
     imageAttachFailed: '附加圖片失敗',
+    pastedContent: '貼上內容',
+    pasteAttachFailed: '無法附加貼上的文字',
     attachImages: '附加圖片',
     clipboard: '剪貼簿',
     noClipboardImage: '剪貼簿中沒有圖片',

apps/desktop/src/i18n/zh.ts

@@ -3103,6 +3103,8 @@ export const zh: Translations = {
     imageAttach: '附加图片',
     imageWriteFailed: '无法将图片写入磁盘。',
     imageAttachFailed: '附加图片失败',
+    pastedContent: '粘贴内容',
+    pasteAttachFailed: '无法附加粘贴的文本',
     attachImages: '附加图片',
     clipboard: '剪贴板',
     noClipboardImage: '剪贴板中没有图片',