diff --git a/.changeset/tidy-codex-shift-arrows.md b/.changeset/tidy-codex-shift-arrows.md
index a46d4fce..ff430edf 100644
--- a/.changeset/tidy-codex-shift-arrows.md
+++ b/.changeset/tidy-codex-shift-arrows.md
@@ -2,4 +2,4 @@
 "aicodeman": patch
 ---
 
-Add Shift+Left and Shift+Right buttons to the default and extended mobile agent keyboard bars, enabling Codex queued-message editing and prompt-stack navigation. Flush locally buffered drafts before navigation and keep terminal focus after taps.
+Add Shift+Left and Shift+Right buttons to the default and extended mobile agent keyboard bars, shown only on Codex sessions, enabling Codex queued-message editing and prompt-stack navigation. Flush locally buffered drafts before navigation and keep terminal focus after taps.
diff --git a/README.md b/README.md
index e53c540f..27ba7db2 100644
--- a/README.md
+++ b/README.md
@@ -209,7 +209,7 @@ The most responsive AI coding agent experience on any phone. Full xterm.js termi
 <tr><td>Password typing on phone</td><td><b>QR code scan — instant auth</b></td></tr>
 </table>
 
-- **Keyboard accessory bar** — `⇧←` / `⇧→` send Shift+Left / Shift+Right in both default and extended agent layouts (Codex defaults: edit the last queued message / return through the prompt stack); `/init`, `/clear`, `/compact` quick-action buttons above the virtual keyboard; destructive commands require a double-press to confirm, so you never fire one by accident
+- **Keyboard accessory bar** — `/init`, `/clear`, `/compact` quick-action buttons above the virtual keyboard; destructive commands require a double-press to confirm, so you never fire one by accident; on Codex sessions the bar also shows `⇧←` / `⇧→` (Shift+Left / Shift+Right: edit the last queued message / return through the prompt stack)
 - **Dedicated Enter button** — replays the keypress through the terminal, so text buffered by local echo is flushed first rather than stranded
 - **Swipe navigation & smart keyboard handling** — swipe left/right to switch sessions; toolbar and terminal shift up when the keyboard opens (`visualViewport` API)
 - **Built for phones** — safe-area insets for notch and home indicator, 44px touch targets, bottom-sheet case picker, native momentum scrolling
diff --git a/src/web/public/keyboard-accessory.js b/src/web/public/keyboard-accessory.js
index 4215cd35..9e954ff5 100644
--- a/src/web/public/keyboard-accessory.js
+++ b/src/web/public/keyboard-accessory.js
@@ -4,8 +4,10 @@
  * Defines three exports:
  *
  * - KeyboardAccessoryBar (singleton object) — Quick action buttons shown above the virtual
- *   keyboard on mobile: arrow up/down, /init, Tab, Shift+Left/Right, paste, Esc, and dismiss (the extended
- *   bar adds /clear, /compact, Shift+Tab and more). Tab flushes any locally-buffered
+ *   keyboard on mobile: arrow up/down, /init, Tab, paste, Esc, and dismiss (the extended
+ *   bar adds /clear, /compact, Shift+Tab and more). Shift+Left/Right ship in both agent
+ *   layouts but are revealed only on Codex sessions (`codex-enabled` marker class on the
+ *   bar, synced on every session switch), since they are Codex bindings. Tab flushes any locally-buffered
  *   prompt text to the PTY before sending \t, so completion applies to what was typed.
  *   The paste button opens a dialog that handles both text paste and image attach
  *   (native picker + best-effort image paste, routed through app._uploadAndInsertImages).
@@ -661,8 +663,8 @@ const KeyboardAccessoryBar = {
       </button>
       <button class="accessory-btn" data-action="init" title="/init">/init</button>
       <button class="accessory-btn" data-action="tab" title="Tab">Tab</button>
-      <button class="accessory-btn" data-action="shift-left" title="Shift+Left (Codex: edit queued message)" aria-label="Shift+Left (Codex: edit queued message)">⇧←</button>
-      <button class="accessory-btn" data-action="shift-right" title="Shift+Right (Codex: prompt stack back)" aria-label="Shift+Right (Codex: prompt stack back)">⇧→</button>
+      <button class="accessory-btn accessory-btn-codex" data-action="shift-left" title="Shift+Left (Codex: edit queued message)" aria-label="Shift+Left (Codex: edit queued message)">⇧←</button>
+      <button class="accessory-btn accessory-btn-codex" data-action="shift-right" title="Shift+Right (Codex: prompt stack back)" aria-label="Shift+Right (Codex: prompt stack back)">⇧→</button>
       <button class="accessory-btn" data-action="paste" title="Paste from clipboard">
         <svg width="14" height="14" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2">
           <path d="M16 4h2a2 2 0 0 1 2 2v14a2 2 0 0 1-2 2H6a2 2 0 0 1-2-2V6a2 2 0 0 1 2-2h2"/>
@@ -748,8 +750,8 @@ const KeyboardAccessoryBar = {
       <button class="accessory-btn" data-action="clear-input" title="Clear the current unsent input">&#x232B; All</button>
       <button class="accessory-btn accessory-btn-rmm" data-action="readmymind" title="Read My Mind: predict your next prompt">🧠</button>
       <button class="accessory-btn" data-action="tab" title="Tab">Tab</button>
-      <button class="accessory-btn" data-action="shift-left" title="Shift+Left (Codex: edit queued message)" aria-label="Shift+Left (Codex: edit queued message)">⇧←</button>
-      <button class="accessory-btn" data-action="shift-right" title="Shift+Right (Codex: prompt stack back)" aria-label="Shift+Right (Codex: prompt stack back)">⇧→</button>
+      <button class="accessory-btn accessory-btn-codex" data-action="shift-left" title="Shift+Left (Codex: edit queued message)" aria-label="Shift+Left (Codex: edit queued message)">⇧←</button>
+      <button class="accessory-btn accessory-btn-codex" data-action="shift-right" title="Shift+Right (Codex: prompt stack back)" aria-label="Shift+Right (Codex: prompt stack back)">⇧→</button>
       <button class="accessory-btn" data-action="shift-tab" title="Shift+Tab">⇧Tab</button>
       <button class="accessory-btn" data-action="effort-max" title="/effort max">Max</button>
       <button class="accessory-btn" data-action="ctrl-o" title="Ctrl+O">⌃O</button>
@@ -776,6 +778,9 @@ const KeyboardAccessoryBar = {
     // The 🧠 key is opt-in (`readMyMindEnabled`, synced): it ships in both
     // templates but stays display:none until the bar carries the marker class.
     this.syncReadMyMind();
+    // The ⇧←/⇧→ keys are Codex bindings: same shape, gated on the active
+    // session's mode instead of a setting.
+    this.syncCodexKeys();
 
     // Add click handlers — preventDefault stops event from reaching terminal
     this.element.addEventListener('click', (e) => {
@@ -819,6 +824,7 @@ const KeyboardAccessoryBar = {
   refreshForActiveSession() {
     this.clearCtrl();
     this._applyLayout(this._resolveMode());
+    this.syncCodexKeys();
   },
 
   /** Which layout the current state calls for. */
@@ -831,6 +837,11 @@ const KeyboardAccessoryBar = {
     return app.sessions?.get(app.activeSessionId)?.mode === 'shell';
   },
 
+  _isCodexSession() {
+    if (typeof app === 'undefined' || !app.activeSessionId) return false;
+    return app.sessions?.get(app.activeSessionId)?.mode === 'codex';
+  },
+
   /** Swap the button set in the DOM. */
   _applyLayout(mode) {
     if (!this.element || mode === this._mode) return;
@@ -1019,6 +1030,20 @@ const KeyboardAccessoryBar = {
     this.element.classList.toggle('rmm-enabled', enabled === true);
   },
 
+  /** Reveal the ⇧←/⇧→ keys only while the active session runs Codex. They are
+   *  Codex bindings (edit the last queued message / prompt stack back) and do
+   *  nothing in any other CLI, yet a tap still goes through sendNavKey(), which
+   *  hands the session to plain PTY echo for the rest of the prompt, so on a
+   *  phone a dead key would also switch off local echo. Same marker-class
+   *  shape as syncReadMyMind(): the class lives on the BAR because setMode()
+   *  rebuilds the buttons' innerHTML. Synced at init and on every session
+   *  switch (refreshForActiveSession); a session's mode is fixed at create, so
+   *  no other event can change the answer. */
+  syncCodexKeys() {
+    if (!this.element) return;
+    this.element.classList.toggle('codex-enabled', this._isCodexSession());
+  },
+
   /** Send a slash command to the active session.
    *  Sends text and Enter separately so Ink processes them as distinct events. */
   sendCommand(command) {
diff --git a/src/web/public/styles.css b/src/web/public/styles.css
index 2dcf6d15..02902b50 100644
--- a/src/web/public/styles.css
+++ b/src/web/public/styles.css
@@ -11969,6 +11969,18 @@ kbd {
   display: inline-flex;
 }
 
+/* Keyboard-accessory ⇧←/⇧→ keys: Codex bindings (edit the last queued
+   message / prompt stack back), so they are revealed only while the active
+   session runs Codex. Same marker-class shape as the 🧠 key above, for the
+   same reason (the bar's innerHTML is rebuilt on every layout switch); the
+   class is synced from the active session's mode (keyboard-accessory.js). */
+.keyboard-accessory-bar .accessory-btn-codex {
+  display: none;
+}
+.keyboard-accessory-bar.codex-enabled .accessory-btn-codex {
+  display: inline-flex;
+}
+
 .approvals-badge {
   position: absolute;
   top: 2px;
diff --git a/test/mobile-shell-keyboard.test.ts b/test/mobile-shell-keyboard.test.ts
index 7da41ac9..00b2ee78 100644
--- a/test/mobile-shell-keyboard.test.ts
+++ b/test/mobile-shell-keyboard.test.ts
@@ -668,3 +668,75 @@ describe('composer nav keys from the bar', () => {
     expect(app.sendInput).not.toHaveBeenCalled();
   });
 });
+
+describe('Codex shift-arrow keys are gated on the active session', () => {
+  // ⇧←/⇧→ are Codex bindings. They ship in both agent templates, but a tap in
+  // any other CLI would do nothing AND hand the session to PTY echo
+  // (sendNavKey adds it to _echoPassthroughSessions), so on a phone a dead key
+  // would also switch local echo off for the rest of the prompt. The reveal
+  // follows the 🧠 key's shape: a marker class on the BAR element, because
+  // setMode() rebuilds the buttons' innerHTML on every layout switch.
+  const stylesSource = readFileSync(resolve('src/web/public/styles.css'), 'utf8');
+
+  it('marks both shift keys in both agent templates so one CSS rule can hide them', () => {
+    const simple = keyboardSource.match(/_simpleButtons\s*:\s*`([\s\S]*?)`/)?.[1] ?? '';
+    const extended = keyboardSource.match(/_extendedButtons\s*:\s*`([\s\S]*?)`/)?.[1] ?? '';
+    for (const template of [simple, extended]) {
+      expect(template).toMatch(/accessory-btn-codex[^>]*data-action="shift-left"/);
+      expect(template).toMatch(/accessory-btn-codex[^>]*data-action="shift-right"/);
+    }
+  });
+
+  it('hides the keys in styles.css until the bar carries codex-enabled', () => {
+    expect(stylesSource).toMatch(/\.keyboard-accessory-bar \.accessory-btn-codex \{\s*display: none;/);
+    expect(stylesSource).toMatch(
+      /\.keyboard-accessory-bar\.codex-enabled \.accessory-btn-codex \{\s*display: inline-flex;/
+    );
+  });
+
+  it.each(['simple', 'extended'])('carries codex-enabled for a codex session in the %s layout', (mode) => {
+    const { bar, barElement } = loadBar('codex');
+    bar.setMode(mode);
+    expect(barElement.classList.contains('codex-enabled')).toBe(true);
+    // The buttons themselves are still in the DOM; the class is what reveals them.
+    expect(barElement.actions).toContain('shift-left');
+    expect(barElement.actions).toContain('shift-right');
+  });
+
+  it.each(['claude', 'shell', 'pi', 'omp', 'deepseek'])(
+    'does not carry codex-enabled for a %s session',
+    (sessionMode) => {
+      const { bar, barElement } = loadBar(sessionMode);
+      bar.setMode('extended');
+      expect(barElement.classList.contains('codex-enabled')).toBe(false);
+    }
+  );
+
+  it('re-syncs the class on a session switch, in both directions', () => {
+    const { app, bar, barElement } = loadBar('codex');
+    expect(barElement.classList.contains('codex-enabled')).toBe(true);
+
+    app.sessions.set('session-2', { mode: 'claude' });
+    app.activeSessionId = 'session-2';
+    bar.refreshForActiveSession();
+    expect(barElement.classList.contains('codex-enabled')).toBe(false);
+
+    app.activeSessionId = 'session-1';
+    bar.refreshForActiveSession();
+    expect(barElement.classList.contains('codex-enabled')).toBe(true);
+  });
+
+  it('drops the class when no session is active (welcome screen)', () => {
+    const { app, bar, barElement } = loadBar('codex');
+    app.activeSessionId = '';
+    bar.refreshForActiveSession();
+    expect(barElement.classList.contains('codex-enabled')).toBe(false);
+  });
+
+  it('is wired at init and on every session switch, like the 🧠 key', () => {
+    const initBody = keyboardSource.match(/\n  init\(\) \{([\s\S]*?)\n  \},/)?.[1] ?? '';
+    const refreshBody = keyboardSource.match(/\n  refreshForActiveSession\(\) \{([\s\S]*?)\n  \},/)?.[1] ?? '';
+    expect(initBody).toContain('this.syncCodexKeys();');
+    expect(refreshBody).toContain('this.syncCodexKeys();');
+  });
+});