diff --git a/codex-rs/tui/src/app/input.rs b/codex-rs/tui/src/app/input.rs
index 4675d78f2b..b24410da1e 100644
--- a/codex-rs/tui/src/app/input.rs
+++ b/codex-rs/tui/src/app/input.rs
@@ -308,42 +308,11 @@ impl App {
         }
 
         let app_keymap_shortcuts_available = self.app_keymap_shortcuts_available();
-
-        let side_toggle_bindings = &self.keymap.app.toggle_side_conversation;
         if app_keymap_shortcuts_available
-            && (side_toggle_bindings.is_pressed(key_event)
-                || side_toggle_bindings.contains(&crate::key_hint::ctrl(KeyCode::Char('/')))
-                    && crate::key_hint::ctrl(KeyCode::Char('7')).is_press(key_event))
+            && self
+                .handle_shared_app_keymap_action(tui, app_server, key_event)
+                .await
         {
-            if let Err(err) = self.toggle_side_conversation(tui, app_server).await {
-                self.chat_widget
-                    .add_error_message(format!("Failed to switch side conversation: {err}"));
-            }
-            return;
-        }
-
-        if app_keymap_shortcuts_available && self.keymap.app.toggle_vim_mode.is_pressed(key_event) {
-            self.chat_widget.toggle_vim_mode_and_notify();
-            return;
-        }
-
-        if app_keymap_shortcuts_available
-            && self.keymap.app.toggle_fast_mode.is_pressed(key_event)
-            && self.chat_widget.can_toggle_fast_mode_from_keybinding()
-        {
-            self.chat_widget.toggle_fast_mode_from_ui();
-            return;
-        }
-
-        if app_keymap_shortcuts_available && self.keymap.app.toggle_raw_output.is_pressed(key_event)
-        {
-            let enabled = !self.chat_widget.raw_output_mode();
-            self.apply_raw_output_mode(tui, enabled, /*notify*/ false);
-            return;
-        }
-
-        if app_keymap_shortcuts_available && self.keymap.app.open_agents.is_pressed(key_event) {
-            self.open_agents_overview(app_server);
             return;
         }
 
@@ -356,27 +325,7 @@ impl App {
             return;
         }
 
-        if app_keymap_shortcuts_available
-            && self.keymap.app.open_external_editor.is_pressed(key_event)
-        {
-            // Only launch the external editor if there is no overlay and the bottom pane is not in use.
-            // Note that it can be launched while a task is running to enable editing while the previous turn is ongoing.
-            if self.overlay.is_none()
-                && self.chat_widget.can_launch_external_editor()
-                && self.chat_widget.external_editor_state() == ExternalEditorState::Closed
-            {
-                self.request_external_editor_launch(tui);
-            }
-            return;
-        }
-
-        if !self.chat_widget.has_active_view()
-            && self
-                .current_displayed_thread_id()
-                .is_some_and(|id| self.thread_unavailable(id))
-            && !(key_event.modifiers.contains(KeyModifiers::CONTROL)
-                && matches!(key_event.code, KeyCode::Char('c' | 'd')))
-        {
+        if self.should_handle_unavailable_thread_key(key_event) {
             self.chat_widget.handle_disconnected_key(key_event);
             return;
         }
@@ -399,22 +348,6 @@ impl App {
         }
 
         match key_event {
-            _ if app_keymap_shortcuts_available
-                && self.keymap.app.clear_terminal.is_pressed(key_event) =>
-            {
-                if !self.chat_widget.can_run_ctrl_l_clear_now() {
-                    return;
-                }
-                if let Err(err) = self.clear_terminal_ui(tui, /*redraw_header*/ false) {
-                    tracing::warn!(error = %err, "failed to clear terminal UI");
-                    self.chat_widget
-                        .add_error_message(format!("Failed to clear terminal UI: {err}"));
-                } else {
-                    self.reset_app_ui_state_after_clear();
-                    self.queue_clear_ui_header(tui);
-                    tui.frame_requester().schedule_frame();
-                }
-            }
             // Enter confirms backtrack when primed + count > 0. Otherwise pass to widget.
             KeyEvent {
                 code: KeyCode::Enter,
@@ -447,6 +380,89 @@ impl App {
         };
     }
 
+    pub(crate) async fn handle_shared_app_keymap_action(
+        &mut self,
+        tui: &mut tui::Tui,
+        app_server: &mut AppServerSession,
+        key_event: KeyEvent,
+    ) -> bool {
+        let side_toggle_bindings = &self.keymap.app.toggle_side_conversation;
+        if side_toggle_bindings.is_pressed(key_event)
+            || side_toggle_bindings.contains(&crate::key_hint::ctrl(KeyCode::Char('/')))
+                && crate::key_hint::ctrl(KeyCode::Char('7')).is_press(key_event)
+        {
+            if let Err(err) = self.toggle_side_conversation(tui, app_server).await {
+                self.chat_widget
+                    .add_error_message(format!("Failed to switch side conversation: {err}"));
+            }
+            return true;
+        }
+
+        if self.keymap.app.toggle_vim_mode.is_pressed(key_event) {
+            self.chat_widget.toggle_vim_mode_and_notify();
+            return true;
+        }
+
+        if self.keymap.app.toggle_fast_mode.is_pressed(key_event)
+            && self.chat_widget.can_toggle_fast_mode_from_keybinding()
+        {
+            self.chat_widget.toggle_fast_mode_from_ui();
+            return true;
+        }
+
+        if self.keymap.app.toggle_raw_output.is_pressed(key_event) {
+            let enabled = !self.chat_widget.raw_output_mode();
+            self.apply_raw_output_mode(tui, enabled, /*notify*/ false);
+            return true;
+        }
+
+        if self.keymap.app.open_agents.is_pressed(key_event) {
+            self.open_agents_overview(app_server);
+            return true;
+        }
+
+        if self.keymap.app.open_external_editor.is_pressed(key_event) {
+            if self.overlay.is_none()
+                && self.chat_widget.can_launch_external_editor()
+                && self.chat_widget.external_editor_state() == ExternalEditorState::Closed
+            {
+                self.request_external_editor_launch(tui);
+            }
+            return true;
+        }
+
+        if self.keymap.app.clear_terminal.is_pressed(key_event) {
+            // Leave cached history intact and let the unavailable-thread input path handle this key.
+            if self.should_handle_unavailable_thread_key(key_event) {
+                return false;
+            }
+            if !self.chat_widget.can_run_ctrl_l_clear_now() {
+                return true;
+            }
+            if let Err(err) = self.clear_terminal_ui(tui, /*redraw_header*/ false) {
+                tracing::warn!(error = %err, "failed to clear terminal UI");
+                self.chat_widget
+                    .add_error_message(format!("Failed to clear terminal UI: {err}"));
+            } else {
+                self.reset_app_ui_state_after_clear();
+                self.queue_clear_ui_header(tui);
+                tui.frame_requester().schedule_frame();
+            }
+            return true;
+        }
+
+        false
+    }
+
+    fn should_handle_unavailable_thread_key(&self, key_event: KeyEvent) -> bool {
+        !self.chat_widget.has_active_view()
+            && self
+                .current_displayed_thread_id()
+                .is_some_and(|id| self.thread_unavailable(id))
+            && !(key_event.modifiers.contains(KeyModifiers::CONTROL)
+                && matches!(key_event.code, KeyCode::Char('c' | 'd')))
+    }
+
     pub(super) fn should_handle_backtrack_esc(&self, key_event: KeyEvent) -> bool {
         !self.chat_widget.side_conversation_active()
             && self.chat_widget.is_normal_backtrack_mode()
diff --git a/codex-rs/tui/src/app/tests.rs b/codex-rs/tui/src/app/tests.rs
index 3a9b3db5a9..6971dab720 100644
--- a/codex-rs/tui/src/app/tests.rs
+++ b/codex-rs/tui/src/app/tests.rs
@@ -38,6 +38,8 @@ mod startup;
 mod stream_animation_tests;
 #[path = "tests/thread_usage.rs"]
 mod thread_usage;
+#[path = "tests/transcript_composer.rs"]
+mod transcript_composer;
 #[path = "tests/turn_submission.rs"]
 mod turn_submission;
 
diff --git a/codex-rs/tui/src/app/tests/key_chords.rs b/codex-rs/tui/src/app/tests/key_chords.rs
index 62210a3476..647aa437c7 100644
--- a/codex-rs/tui/src/app/tests/key_chords.rs
+++ b/codex-rs/tui/src/app/tests/key_chords.rs
@@ -115,6 +115,30 @@ async fn completed_global_chord_reuses_the_existing_action_handler() -> Result<(
     Ok(())
 }
 
+#[tokio::test]
+async fn completed_global_chords_toggle_output_and_request_external_editor() -> Result<()> {
+    let (mut app, mut tui, mut app_server) = chord_app().await?;
+    let config = toml::from_str(
+        "[global]\ntoggle_raw_output = [\"ctrl-x r\"]\nopen_external_editor = [\"ctrl-x e\"]",
+    )?;
+    app.keymap = RuntimeKeymap::from_config(&config).expect("valid global chords");
+    app.chat_widget.apply_keymap_update(config, &app.keymap);
+
+    for key in [ctrl('x'), KeyCode::Char('r').into()] {
+        press(&mut app, &mut tui, &mut app_server, key).await?;
+    }
+    assert!(app.chat_widget.raw_output_mode());
+
+    for key in [ctrl('x'), KeyCode::Char('e').into()] {
+        press(&mut app, &mut tui, &mut app_server, key).await?;
+    }
+    assert_eq!(
+        app.chat_widget.external_editor_state(),
+        super::ExternalEditorState::Requested
+    );
+    Ok(())
+}
+
 #[tokio::test]
 async fn wrong_second_stroke_passes_through_but_escape_is_consumed() -> Result<()> {
     let (mut app, mut tui, mut app_server) = chord_app().await?;
diff --git a/codex-rs/tui/src/app/tests/navigation_reconnect_tests.rs b/codex-rs/tui/src/app/tests/navigation_reconnect_tests.rs
index d8b59813c2..84f3728d96 100644
--- a/codex-rs/tui/src/app/tests/navigation_reconnect_tests.rs
+++ b/codex-rs/tui/src/app/tests/navigation_reconnect_tests.rs
@@ -390,7 +390,19 @@ async fn reconnect_daemon_command_center_after_socket_replacement_without_a_conv
             let history = drain_history(&mut app, &mut tui, &mut session, &mut events).await?;
             assert!(history.contains("Cached previous conversation"));
 
-            let content = &history[history.find("Cached previous conversation").unwrap()..];
+            app.handle_tui_event(
+                &mut tui,
+                &mut session,
+                TuiEvent::Key(KeyEvent::new(KeyCode::Char('l'), KeyModifiers::CONTROL)),
+            )
+            .await?;
+            let preserved_history =
+                drain_history(&mut app, &mut tui, &mut session, &mut events).await?;
+            assert_eq!(preserved_history, history);
+
+            let content = &preserved_history[preserved_history
+                .find("Cached previous conversation")
+                .unwrap()..];
             assert_snapshot!(
                 "reconnected_unavailable_conversation",
                 format!(
diff --git a/codex-rs/tui/src/app/tests/snapshots/codex_tui__app__tests__transcript_composer__transcript_flag_off_viewer.snap b/codex-rs/tui/src/app/tests/snapshots/codex_tui__app__tests__transcript_composer__transcript_flag_off_viewer.snap
new file mode 100644
index 0000000000..8a310ff6bc
--- /dev/null
+++ b/codex-rs/tui/src/app/tests/snapshots/codex_tui__app__tests__transcript_composer__transcript_flag_off_viewer.snap
@@ -0,0 +1,15 @@
+---
+source: tui/src/app/tests/transcript_composer.rs
+expression: text
+---
+/ T R A N S C R I P T / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / /
+
+› first
+
+
+
+› second
+
+───────────────────────────────────────────────────────────────────────────────────────────── 100% ─
+ ↑/↓ to scroll   pgup/pgdn to page   home/end to jump
+ q to quit   esc to edit prev
diff --git a/codex-rs/tui/src/app/tests/transcript_composer.rs b/codex-rs/tui/src/app/tests/transcript_composer.rs
new file mode 100644
index 0000000000..358e05d031
--- /dev/null
+++ b/codex-rs/tui/src/app/tests/transcript_composer.rs
@@ -0,0 +1,109 @@
+//! Regression coverage for transcript viewer input and prompt selection.
+//!
+//! The default-off feature must leave the existing viewer and its draft intact.
+
+use super::*;
+use crossterm::event::KeyCode;
+use crossterm::event::KeyEvent;
+use crossterm::event::KeyModifiers;
+use pretty_assertions::assert_eq;
+
+async fn press_key(
+    app: &mut App,
+    tui: &mut crate::tui::Tui,
+    app_server: &mut AppServerSession,
+    code: KeyCode,
+) -> Result<()> {
+    app.handle_tui_event(
+        tui,
+        app_server,
+        TuiEvent::Key(KeyEvent::new(code, KeyModifiers::NONE)),
+    )
+    .await?;
+    Ok(())
+}
+
+#[tokio::test]
+async fn transcript_flag_off_preserves_viewer_and_backtracking() -> Result<()> {
+    let (mut app, mut app_event_rx, _op_rx) = make_test_app_with_channels().await;
+    let keymap_config = toml::from_str("[composer]\nsubmit = [\"ctrl-x enter\"]")?;
+    app.keymap =
+        crate::keymap::RuntimeKeymap::from_config(&keymap_config).expect("valid composer chord");
+    app.chat_widget
+        .apply_keymap_update(keymap_config, &app.keymap);
+    let mut app_server = start_config_write_test_app_server(&app).await?;
+    let mut tui = crate::tui::test_support::make_test_tui()?;
+    let session = test_thread_session(ThreadId::new(), app.config.cwd.to_path_buf());
+    app.chat_widget.handle_thread_session(session);
+    app.transcript_cells = ["first", "second"]
+        .map(|message| {
+            Arc::new(UserHistoryCell {
+                message: message.into(),
+                text_elements: Vec::new(),
+                local_image_paths: Vec::new(),
+                remote_image_urls: Vec::new(),
+            }) as Arc<dyn HistoryCell>
+        })
+        .to_vec();
+    app.chat_widget
+        .apply_external_edit("preserved draft".into());
+    app.open_transcript_overlay(&mut tui);
+    for event in [
+        TuiEvent::Paste("not composer input".into()),
+        TuiEvent::Key(KeyEvent::new(KeyCode::Char('j'), KeyModifiers::NONE)),
+    ] {
+        app.handle_tui_event(&mut tui, &mut app_server, event)
+            .await?;
+    }
+    assert_eq!(
+        app.chat_widget.composer_text_with_pending(),
+        "preserved draft"
+    );
+    let chord_prefix = KeyEvent::new(KeyCode::Char('x'), KeyModifiers::CONTROL);
+    app.handle_tui_event(&mut tui, &mut app_server, TuiEvent::Key(chord_prefix))
+        .await?;
+    assert!(!app.key_chord_matcher.is_pending());
+    assert!(!app.backtrack.overlay_preview_active);
+    let area = Rect::new(
+        /*x*/ 0, /*y*/ 0, /*width*/ 100, /*height*/ 12,
+    );
+    let mut buffer = ratatui::buffer::Buffer::empty(area);
+    let Some(Overlay::Transcript(overlay)) = &mut app.overlay else {
+        panic!("viewer closed")
+    };
+    overlay.render(area, &mut buffer);
+    let text = buffer
+        .content()
+        .chunks(usize::from(area.width))
+        .map(|row| {
+            row.iter()
+                .map(ratatui::buffer::Cell::symbol)
+                .collect::<String>()
+                .trim_end()
+                .to_string()
+        })
+        .collect::<Vec<_>>()
+        .join("\n");
+    insta::assert_snapshot!("transcript_flag_off_viewer", text);
+    for (key, selected) in [
+        (KeyCode::Esc, 1),
+        (KeyCode::Esc, 0),
+        (KeyCode::Right, 1),
+        (KeyCode::Right, 1),
+    ] {
+        press_key(&mut app, &mut tui, &mut app_server, key).await?;
+        assert_eq!(app.backtrack.nth_user_message, selected);
+    }
+    press_key(&mut app, &mut tui, &mut app_server, KeyCode::Enter).await?;
+    assert!(app.overlay.is_none());
+    assert!(
+        std::iter::from_fn(|| app_event_rx.try_recv().ok()).any(|event| matches!(
+            event,
+            AppEvent::ForkSessionForPromptEdit {
+                nth_user_message: 1,
+                ..
+            }
+        ))
+    );
+    Ok(())
+}
diff --git a/codex-rs/tui/src/app_backtrack.rs b/codex-rs/tui/src/app_backtrack.rs
index 6f36701033..242b0215c6 100644
--- a/codex-rs/tui/src/app_backtrack.rs
+++ b/codex-rs/tui/src/app_backtrack.rs
@@ -21,6 +21,8 @@
 //! `TranscriptOverlay::sync_live_tail`. This preserves the invariant that the overlay reflects
 //! both committed history and in-flight activity without changing flush or coalescing behavior.
 
+mod legacy_input;
+
 use std::any::TypeId;
 use std::sync::Arc;
 
@@ -93,79 +95,7 @@ impl App {
         app_server: &mut AppServerSession,
         event: TuiEvent,
     ) -> Result<bool> {
-        if let TuiEvent::Key(key_event) = &event
-            && let Some(Overlay::Transcript(overlay)) = self.overlay.as_ref()
-            && (overlay.should_load_older(*key_event)
-                || (self.backtrack.overlay_preview_active
-                    && self.backtrack.nth_user_message == 0
-                    && matches!(key_event.code, KeyCode::Esc | KeyCode::Left)
-                    && matches!(key_event.kind, KeyEventKind::Press | KeyEventKind::Repeat)))
-            && let Some(thread_id) = self.chat_widget.thread_id()
-            && app_server.has_older_history(thread_id)
-            && self.request_older_history_page(app_server, thread_id)
-        {
-            if let Some(Overlay::Transcript(overlay)) = self.overlay.as_mut() {
-                overlay.set_history_state(if overlay.should_load_from_start(*key_event) {
-                    TranscriptHistoryState::LoadingBeginning
-                } else {
-                    TranscriptHistoryState::LoadingOlder
-                });
-            }
-            tui.frame_requester().schedule_frame();
-        }
-        if self.backtrack.overlay_preview_active {
-            match event {
-                TuiEvent::Key(KeyEvent {
-                    code: KeyCode::Esc,
-                    kind: KeyEventKind::Press | KeyEventKind::Repeat,
-                    ..
-                }) => {
-                    self.overlay_step_backtrack(tui, event)?;
-                    Ok(true)
-                }
-                TuiEvent::Key(KeyEvent {
-                    code: KeyCode::Left,
-                    kind: KeyEventKind::Press | KeyEventKind::Repeat,
-                    ..
-                }) => {
-                    self.overlay_step_backtrack(tui, event)?;
-                    Ok(true)
-                }
-                TuiEvent::Key(KeyEvent {
-                    code: KeyCode::Right,
-                    kind: KeyEventKind::Press | KeyEventKind::Repeat,
-                    ..
-                }) => {
-                    self.overlay_step_backtrack_forward(tui, event)?;
-                    Ok(true)
-                }
-                TuiEvent::Key(KeyEvent {
-                    code: KeyCode::Enter,
-                    kind: KeyEventKind::Press,
-                    ..
-                }) => {
-                    self.overlay_confirm_backtrack(tui);
-                    Ok(true)
-                }
-                _ => {
-                    self.overlay_forward_event(tui, event)?;
-                    Ok(true)
-                }
-            }
-        } else if let TuiEvent::Key(KeyEvent {
-            code: KeyCode::Esc,
-            kind: KeyEventKind::Press | KeyEventKind::Repeat,
-            ..
-        }) = event
-        {
-            // First Esc in transcript overlay: begin backtrack preview at latest user message.
-            self.begin_overlay_backtrack_preview(tui);
-            Ok(true)
-        } else {
-            // Not in backtrack mode: forward events to the overlay widget.
-            self.overlay_forward_event(tui, event)?;
-            Ok(true)
-        }
+        self.handle_legacy_transcript_event(tui, app_server, event)
     }
 
     /// Handle global Esc presses for backtracking when no overlay is present.
diff --git a/codex-rs/tui/src/app_backtrack/legacy_input.rs b/codex-rs/tui/src/app_backtrack/legacy_input.rs
new file mode 100644
index 0000000000..c36e83bd76
--- /dev/null
+++ b/codex-rs/tui/src/app_backtrack/legacy_input.rs
@@ -0,0 +1,74 @@
+//! Input routing for the read-only transcript viewer.
+//!
+//! Preview selection is shared with the interactive transcript path so both
+//! modes retain the same prompt navigation and confirmation behavior.
+
+use super::*;
+
+impl App {
+    pub(super) fn handle_legacy_transcript_event(
+        &mut self,
+        tui: &mut tui::Tui,
+        app_server: &mut AppServerSession,
+        event: TuiEvent,
+    ) -> Result<bool> {
+        if let TuiEvent::Key(key_event) = &event
+            && let Some(Overlay::Transcript(overlay)) = self.overlay.as_ref()
+            && (overlay.should_load_older(*key_event)
+                || (self.backtrack.overlay_preview_active
+                    && self.backtrack.nth_user_message == 0
+                    && matches!(key_event.code, KeyCode::Esc | KeyCode::Left)
+                    && matches!(key_event.kind, KeyEventKind::Press | KeyEventKind::Repeat)))
+            && let Some(thread_id) = self.chat_widget.thread_id()
+            && app_server.has_older_history(thread_id)
+            && self.request_older_history_page(app_server, thread_id)
+        {
+            if let Some(Overlay::Transcript(overlay)) = self.overlay.as_mut() {
+                overlay.set_history_state(if overlay.should_load_from_start(*key_event) {
+                    TranscriptHistoryState::LoadingBeginning
+                } else {
+                    TranscriptHistoryState::LoadingOlder
+                });
+            }
+            tui.frame_requester().schedule_frame();
+        }
+        if self.backtrack.overlay_preview_active {
+            return self.handle_backtrack_preview_event(tui, event);
+        }
+        match event {
+            TuiEvent::Key(KeyEvent {
+                code: KeyCode::Esc,
+                kind: KeyEventKind::Press | KeyEventKind::Repeat,
+                ..
+            }) => self.begin_overlay_backtrack_preview(tui),
+            event => self.overlay_forward_event(tui, event)?,
+        }
+        Ok(true)
+    }
+
+    pub(super) fn handle_backtrack_preview_event(
+        &mut self,
+        tui: &mut tui::Tui,
+        event: TuiEvent,
+    ) -> Result<bool> {
+        match event {
+            TuiEvent::Key(KeyEvent {
+                code: KeyCode::Esc | KeyCode::Left,
+                kind: KeyEventKind::Press | KeyEventKind::Repeat,
+                ..
+            }) => self.overlay_step_backtrack(tui, event)?,
+            TuiEvent::Key(KeyEvent {
+                code: KeyCode::Right,
+                kind: KeyEventKind::Press | KeyEventKind::Repeat,
+                ..
+            }) => self.overlay_step_backtrack_forward(tui, event)?,
+            TuiEvent::Key(KeyEvent {
+                code: KeyCode::Enter,
+                kind: KeyEventKind::Press,
+                ..
+            }) => self.overlay_confirm_backtrack(tui),
+            event => self.overlay_forward_event(tui, event)?,
+        }
+        Ok(true)
+    }
+}