modelstudioai · DragonnZhang · Jul 6, 2026 · Jul 6, 2026 · Jul 16, 2026
diff --git a/apps/electron/src/renderer/components/app-shell/ChatDisplay.tsx b/apps/electron/src/renderer/components/app-shell/ChatDisplay.tsx
@@ -1699,8 +1699,11 @@ export const ChatDisplay = React.forwardRef<ChatDisplayHandle, ChatDisplayProps>
               }}
             >
               <ScrollArea className="h-full min-w-0" viewportRef={scrollViewportRef}>
-              <div className={cn(
-                CHAT_LAYOUT.maxWidth,
+              <div
+                data-testid="chat-messages-container"
+                style={compactMode ? undefined : { maxWidth: 'var(--chat-content-max-width, 840px)' }}
+                className={cn(
+                compactMode && CHAT_LAYOUT.maxWidth,
                 "mx-auto min-w-0",
                 compactMode ? "px-3 py-4 space-y-2" : [CHAT_LAYOUT.containerPadding, CHAT_LAYOUT.messageSpacing]
               )}>

diff --git a/apps/electron/src/renderer/components/app-shell/input/ChatInputZone.tsx b/apps/electron/src/renderer/components/app-shell/input/ChatInputZone.tsx
@@ -83,8 +83,9 @@ export function ChatInputZone({
 
   return (
     <div
+      style={compactMode ? undefined : { maxWidth: 'var(--chat-content-max-width, 840px)' }}
       className={cn(
-        CHAT_LAYOUT.maxWidth,
+        compactMode && CHAT_LAYOUT.maxWidth,
         'mx-auto w-full mt-1',
         compactMode ? 'px-2 pb-3' : 'px-3 @xs/panel:px-4 pb-4',
         className,

diff --git a/apps/electron/src/renderer/components/settings/SettingsSegmentedControl.tsx b/apps/electron/src/renderer/components/settings/SettingsSegmentedControl.tsx
@@ -28,6 +28,8 @@ export interface SettingsSegmentedControlProps<T extends string = string> {
   size?: 'sm' | 'md'
   /** Additional className */
   className?: string
+  /** Optional test id — applied to the group and, suffixed with `-<value>`, to each option */
+  testId?: string
 }
 
 /**
@@ -50,10 +52,12 @@ export function SettingsSegmentedControl<T extends string = string>({
   options,
   size = 'md',
   className,
+  testId,
 }: SettingsSegmentedControlProps<T>) {
   return (
     <div
       role="radiogroup"
+      data-testid={testId}
       className={cn('inline-flex gap-1', className)}
     >
       {options.map((option) => {
@@ -65,6 +69,8 @@ export function SettingsSegmentedControl<T extends string = string>({
             type="button"
             role="radio"
             aria-checked={isSelected}
+            data-testid={testId ? `${testId}-${option.value}` : undefined}
+            data-value={option.value}
             onClick={() => onValueChange(option.value)}
             className={cn(
               'flex items-center gap-1.5 rounded-lg transition-all',

diff --git a/apps/electron/src/renderer/context/ConversationWidthContext.tsx b/apps/electron/src/renderer/context/ConversationWidthContext.tsx
@@ -0,0 +1,96 @@
+/**
+ * ConversationWidthContext
+ *
+ * App-wide "Conversation width" preference — controls the reading-column width
+ * of the chat transcript and composer, mirroring the width controls in
+ * comparable desktop clients (Claude Desktop, ChatGPT desktop, Codex / VS Code).
+ *
+ * Three modes:
+ *  - `comfortable` (default) — the classic ~840px reading column;
+ *  - `wide` — a roomier 1100px column for code-heavy conversations;
+ *  - `full` — no max-width, uses the full available panel width.
+ *
+ * When applied it:
+ *  - sets `data-conversation-width="<mode>"` on `<html>` (for CSS hooks + tests);
+ *  - drives a CSS custom property `--chat-content-max-width` on `<html>`
+ *    (`840px` / `1100px` / `none`). The transcript container and composer read
+ *    it via `max-width: var(--chat-content-max-width, 840px)`, so the fallback
+ *    keeps the shared web viewer (`packages/ui`) unchanged at 840px.
+ *
+ * The preference is persisted in `localStorage` (renderer-only, no backend),
+ * mirroring the other lightweight UI prefs in `lib/local-storage.ts`.
+ */
+
+import React, {
+  createContext,
+  useContext,
+  useState,
+  useEffect,
+  useCallback,
+  type ReactNode,
+} from 'react'
+import * as storage from '@/lib/local-storage'
+
+export type ConversationWidth = 'comfortable' | 'wide' | 'full'
+
+/** Resolved CSS `max-width` value for each mode. */
+const MAX_WIDTH_BY_MODE: Record<ConversationWidth, string> = {
+  comfortable: '840px',
+  wide: '1100px',
+  full: 'none',
+}
+
+const CONVERSATION_WIDTH_ATTR = 'data-conversation-width'
+const MAX_WIDTH_VAR = '--chat-content-max-width'
+
+const DEFAULT_WIDTH: ConversationWidth = 'comfortable'
+
+function isConversationWidth(value: unknown): value is ConversationWidth {
+  return value === 'comfortable' || value === 'wide' || value === 'full'
+}
+
+interface ConversationWidthContextType {
+  conversationWidth: ConversationWidth
+  setConversationWidth: (value: ConversationWidth) => void
+}
+
+const ConversationWidthContext = createContext<ConversationWidthContextType | null>(null)
+
+/** Reflect the preference onto <html> so CSS + the transcript/composer can react. */
+function applyConversationWidth(mode: ConversationWidth): void {
+  const root = document.documentElement
+  root.setAttribute(CONVERSATION_WIDTH_ATTR, mode)
+  root.style.setProperty(MAX_WIDTH_VAR, MAX_WIDTH_BY_MODE[mode])
+}
+
+export function ConversationWidthProvider({ children }: { children: ReactNode }) {
+  const [conversationWidth, setConversationWidthState] = useState<ConversationWidth>(() => {
+    const stored = storage.get<ConversationWidth>(storage.KEYS.conversationWidth, DEFAULT_WIDTH)
+    return isConversationWidth(stored) ? stored : DEFAULT_WIDTH
+  })
+
+  // Keep the DOM in sync (also covers the initial value on mount).
+  useEffect(() => {
+    applyConversationWidth(conversationWidth)
+  }, [conversationWidth])
+
+  const setConversationWidth = useCallback((value: ConversationWidth) => {
+    setConversationWidthState(value)
+    storage.set(storage.KEYS.conversationWidth, value)
+    applyConversationWidth(value)
+  }, [])
+
+  return (
+    <ConversationWidthContext.Provider value={{ conversationWidth, setConversationWidth }}>
+      {children}
+    </ConversationWidthContext.Provider>
+  )
+}
+
+export function useConversationWidth(): ConversationWidthContextType {
+  const ctx = useContext(ConversationWidthContext)
+  if (!ctx) {
+    throw new Error('useConversationWidth must be used within a ConversationWidthProvider')
+  }
+  return ctx
+}
diff --git a/apps/electron/src/renderer/lib/local-storage.ts b/apps/electron/src/renderer/lib/local-storage.ts
@@ -56,6 +56,7 @@ export const KEYS = {
   // Appearance
   showConnectionIcons: 'show-connection-icons',
   reduceMotion: 'reduce-motion', // Minimize animations/transitions app-wide
+  conversationWidth: 'conversation-width', // Chat reading-column width: comfortable | wide | full
 
   // What's New
   whatsNewLastSeenVersion: 'whats-new-last-seen-version',

diff --git a/apps/electron/src/renderer/main.tsx b/apps/electron/src/renderer/main.tsx
@@ -7,6 +7,7 @@ import { Provider as JotaiProvider, useAtomValue } from 'jotai'
 import App from './App'
 import { ThemeProvider } from './context/ThemeContext'
 import { ReduceMotionProvider } from './context/ReduceMotionContext'
+import { ConversationWidthProvider } from './context/ConversationWidthContext'
 import { windowWorkspaceIdAtom } from './atoms/sessions'
 import { Toaster } from '@/components/ui/sonner'
 import { PetWindowController } from '@/components/pet/PetWindowController'
@@ -108,9 +109,11 @@ function Root() {
   return (
     <ThemeProvider activeWorkspaceId={workspaceId}>
       <ReduceMotionProvider>
-        <App />
-        <Toaster />
-        <PetWindowController />
+        <ConversationWidthProvider>
+          <App />
+          <Toaster />
+          <PetWindowController />
+        </ConversationWidthProvider>
       </ReduceMotionProvider>
     </ThemeProvider>
   )

diff --git a/apps/electron/src/renderer/pages/settings/AppearanceSettingsPage.tsx b/apps/electron/src/renderer/pages/settings/AppearanceSettingsPage.tsx
@@ -15,6 +15,7 @@ import { HeaderMenu } from '@/components/ui/HeaderMenu'
 import { EditPopover, EditButton, getEditConfig } from '@/components/ui/EditPopover'
 import { useTheme } from '@/context/ThemeContext'
 import { useReduceMotion } from '@/context/ReduceMotionContext'
+import { useConversationWidth } from '@/context/ConversationWidthContext'
 import { useAppShellContext } from '@/context/AppShellContext'
 import { routes } from '@/lib/navigate'
 import { FolderOpen, Monitor, RefreshCw, Sun, Moon } from 'lucide-react'
@@ -143,6 +144,9 @@ export default function AppearanceSettingsPage() {
   // Reduce motion toggle (renderer-only preference, persisted in localStorage)
   const { reduceMotion, setReduceMotion } = useReduceMotion()
 
+  // Conversation width (renderer-only preference, persisted in localStorage)
+  const { conversationWidth, setConversationWidth } = useConversationWidth()
+
   // Pet companion settings + custom pets (synced via shared Jotai atoms)
   const {
     pets,
@@ -387,6 +391,21 @@ export default function AppearanceSettingsPage() {
                     onCheckedChange={setReduceMotion}
                     testId="reduce-motion-toggle"
                   />
+                  <SettingsRow
+                    label={t("settings.appearance.conversationWidth")}
+                    description={t("settings.appearance.conversationWidthDesc")}
+                  >
+                    <SettingsSegmentedControl
+                      value={conversationWidth}
+                      onValueChange={setConversationWidth}
+                      testId="conversation-width-control"
+                      options={[
+                        { value: 'comfortable', label: t("settings.appearance.conversationWidthComfortable") },
+                        { value: 'wide', label: t("settings.appearance.conversationWidthWide") },
+                        { value: 'full', label: t("settings.appearance.conversationWidthFull") },
+                      ]}
+                    />
+                  </SettingsRow>
                 </SettingsCard>
               </SettingsSection>
 

diff --git a/docs/loop/feature-ledger.md b/docs/loop/feature-ledger.md
@@ -32,7 +32,12 @@ log, not the system of record.
 
 | slug | title | source | feasibility | status | issue | pr | branch | updated | notes |
 | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- |
-| copy-message | "Copy" (copy-as-Markdown) action on assistant/agent responses | Codex desktop "Copy as Markdown" (openai/codex #2880, #17241) + Claude/ChatGPT desktop per-message copy | frontend-only | pr-open | [#70](https://github.com/modelstudioai/openwork/issues/70) | [#71](https://github.com/modelstudioai/openwork/pull/71) | loop/copy-message | 2026-07-08 | User messages + code blocks were already copyable, but full assistant responses had only a pop-out button — no copy. Extracted `AssistantMessage` component in `ChatDisplay.tsx` (owns `copied` state, mirrors the existing `ErrorMessage` extraction) with a hover copy button next to pop-out; copies raw `message.content` via `navigator.clipboard.writeText`, 2s "copied" check state, `toast.copyFailed` on error. **Zero new i18n keys** (reuses `common.copy`/`common.copied`/`toast.copyFailed`). Added a general `seed` hook to the e2e harness (`app.ts`/`runner.ts`) so assertions can pre-seed an on-disk session the embedded `SessionManager` loads on boot (no backend). typecheck:all zero-delta; `bun test` 56-failure set byte-identical to main; renderer build ✅; i18n parity ✅ (1544 keys); eslint 0 errors. CDP assertion (`copy-message.assert.ts`) seeds a user+assistant session, opens it, clicks the copy button, and asserts the exact response markdown reaches the (stubbed) clipboard + the button enters its copied state; **could not run locally** (org egress policy 403s the Electron binary download — same block as prior rounds). |
+| conversation-width | "Conversation width" (Comfortable / Wide / Full) setting in Appearance | Claude Desktop wider-chat / ChatGPT desktop width / Codex & VS Code content width | frontend-only | pr-open | [#62](https://github.com/modelstudioai/openwork/issues/62) | [#63](https://github.com/modelstudioai/openwork/pull/63) | loop/conversation-width | 2026-07-06 | Renderer-only pref (localStorage `craft-conversation-width`). New `ConversationWidthProvider` in `main.tsx` sets `data-conversation-width` on `<html>` + drives CSS var `--chat-content-max-width` (840px/1100px/none). Transcript container (`ChatDisplay`) + composer (`ChatInputZone`) read it via `max-width: var(--chat-content-max-width, 840px)`; fallback keeps shared web viewer unchanged. Segmented control in Appearance→Interface; added `testId` to `SettingsSegmentedControl`; 5 new i18n keys ×7 locales. typecheck/`bun test` zero-delta vs main (56-failure set byte-identical); renderer build ✅; i18n parity ✅. CDP assertion `e2e/assertions/conversation-width.assert.ts` included; **could not run locally** (egress 403 blocks Electron binary + `libsignal-node`/`eslint-config` git-tarball deps — same env blocker as #51). |
+| composer-count | Live word / character count indicator in the chat composer | Codex desktop / VS Code / Google Docs status bars | frontend-only | pr-open | [#60](https://github.com/modelstudioai/openwork/issues/60) | [#61](https://github.com/modelstudioai/openwork/pull/61) | loop/composer-count | 2026-07-05 | Opened by a prior run. Draft word count + tooltip (words/chars/lines) in composer toolbar. Awaiting review. |
+| shortcuts-search | Search box on the Settings → Keyboard Shortcuts page | Claude Code Desktop / VS Code keybinding search | frontend-only | pr-open | [#58](https://github.com/modelstudioai/openwork/issues/58) | [#59](https://github.com/modelstudioai/openwork/pull/59) | loop/shortcuts-search | 2026-07-04 | Opened by a prior run. Awaiting review. |
+| recent-commands | Surface recently-used commands in the Command Palette (⌘K) | Claude Code Desktop / VS Code recently-used | frontend-only | pr-open | [#56](https://github.com/modelstudioai/openwork/issues/56) | [#57](https://github.com/modelstudioai/openwork/pull/57) | loop/recent-commands | 2026-07-04 | Opened by a prior run. Awaiting review. |
+| thinking-shortcut | Keyboard shortcut (⌘⇧E) to open the composer's thinking menu | Claude Code Desktop effort menu ⌘⇧E | frontend-only | pr-open | [#54](https://github.com/modelstudioai/openwork/issues/54) | [#55](https://github.com/modelstudioai/openwork/pull/55) | loop/thinking-shortcut | 2026-07-03 | Opened by a prior run. Awaiting review. |
+| prompt-history | Recall previously-sent prompts in the composer with Up / Down arrows | Claude Code / shell / ChatGPT prompt history | frontend-only | pr-open | [#52](https://github.com/modelstudioai/openwork/issues/52) | [#53](https://github.com/modelstudioai/openwork/pull/53) | loop/prompt-history | 2026-07-03 | Opened by a prior run. Awaiting review. |
 | reduce-motion | "Reduce motion" accessibility setting in Appearance | Claude desktop / macOS / Windows reduce-motion + `prefers-reduced-motion` | frontend-only | merged | [#50](https://github.com/modelstudioai/openwork/issues/50) | [#51](https://github.com/modelstudioai/openwork/pull/51) | loop/reduce-motion | 2026-07-08 | **Merged** into `main` (2026-07-06). Renderer-only pref (localStorage) applied app-wide via `<MotionConfig reducedMotion>` + `data-reduce-motion` on `<html>` + global CSS guard. Off ⇒ `reducedMotion="user"` (still honors OS). New `ReduceMotionProvider` in `main.tsx`; toggle in Appearance→Interface; 2 new i18n keys ×7 locales. |
 | composer-expand | Expand / collapse (maximize) toggle for the chat composer | Claude/ChatGPT/Codex desktop composer maximize | frontend-only | pr-open | [#48](https://github.com/modelstudioai/openwork/issues/48) | [#49](https://github.com/modelstudioai/openwork/pull/49) | loop/composer-expand | 2026-07-03 | Opened by a prior run. Adds `isComposerExpanded` toggle in `FreeFormInput`; 2 new i18n keys. Awaiting review. |
 | scroll-to-bottom | "Jump to latest" (scroll-to-bottom) button in the chat transcript | Claude Code / ChatGPT / Codex desktop | frontend-only | pr-open | [#46](https://github.com/modelstudioai/openwork/issues/46) | [#47](https://github.com/modelstudioai/openwork/pull/47) | loop/scroll-to-bottom | 2026-07-02 | Opened by a prior run. Floating jump button in `ChatDisplay` + `seed()` harness hook. Awaiting review. |