[Windows][Desktop] Overflowing right-pane tab strip cannot be scrolled with the mouse wheel

What version of the Codex App are you using (From “About Codex” dialog)?

OpenAI Codex 26.825.5331.0 (x64)

What subscription do you have?

ChatGPT subscription. The exact tier does not appear relevant to this UI reproduction.

What platform is your computer?

Microsoft Windows NT 10.0.26200.0 x64 (Windows 11 25H2, build 26200.9168)

What issue are you seeing?

When enough tabs are open in the Codex Desktop right-hand pane to overflow the available tab-strip width, tabs on the right become hidden with no practical way to reach them by scrolling the strip.

Placing the pointer over the tab strip and rotating the mouse wheel does not move the strip horizontally. There is also no visible horizontal scrollbar, overflow menu, or left/right control. The hidden tabs only become reachable after closing tabs that are currently visible.

This affects the shared right-pane tab strip used by in-app Browser and other pane surfaces; it is not webpage scrolling inside the selected browser tab.

What steps can reproduce the bug?

1. Open Codex Desktop on Windows and open the right-hand pane.
2. Open enough Browser, file, terminal, or other right-pane tabs for the tab strip to exceed the available pane width.
3. Confirm that one or more tabs at the right end are outside the visible strip.
4. Place the pointer directly over the tab strip.
5. Rotate the mouse wheel in both directions.
6. Try to reach the hidden tabs without closing any visible tab.

Actual result: the tab strip does not move, the hidden tabs remain unreachable, and closing visible tabs is the only discovered workaround.

What is the expected behavior?

An overflowing tab strip should remain navigable without closing tabs.

• While the pointer is over an overflowing tab strip, a vertical mouse-wheel gesture should scroll the strip horizontally. Native horizontal-wheel/touchpad deltas should continue to work.
• Wheel input should be consumed only when the tab strip can move in that direction, so reaching either end does not trap normal page scrolling.
• Selecting or opening a tab that is outside the visible range should automatically bring that tab into view using nearest-edge scrolling.
• With too few tabs to overflow, wheel input over the strip should have no side effect.
• An overflow menu or explicit left/right controls could be an additional accessibility path, but should not be required for ordinary mouse-wheel navigation.

Additional information

I searched the tracker before filing. The closest issues are:

• #23314 requested multiple visible in-app Browser tabs, which now exist; this report is specifically about navigating the resulting overflowing tab strip.
• #22808 concerns touchpad horizontal gestures for browser back/forward navigation, not scrolling the app's tab strip.
• #41653 concerns stale ghost tabs that lose their close button, not tabs hidden by normal horizontal overflow.

Suggested interaction logic for the desktop shell:

1. Keep the tab list in a horizontally scrollable container (overflow-x: auto, overflow-y: hidden).
2. On wheel, prefer a meaningful native deltaX; otherwise translate normalized deltaY into horizontal movement.
3. Call preventDefault() only if scrollLeft actually changes.
4. When the selected tab changes, call scrollIntoView({ block: "nearest", inline: "nearest" }) for that tab.

Useful regression cases:

• Overflow at the left edge: wheel toward the start does not consume the event.
• Overflow at the right edge: wheel toward the end does not consume the event.
• Mixed touchpad deltas: one gesture is applied once, without adding both axes and overscrolling.
• Non-overflowing strip: no horizontal movement and no intercepted page scroll.
• Keyboard/programmatic tab selection: a hidden selected tab becomes visible.

The public openai/codex repository does not contain the desktop tab-strip implementation, and its contribution guide says external code pull requests are not accepted, so this is provided as an implementation-ready UI report rather than a code PR.

The public openai/codex repository does not contain the desktop tab-strip implementation, and the report names no file or test entry point. Confirm the behavior in the Windows desktop shell; done means overflowing strips support wheel and native horizontal scrolling, reveal selected tabs, and preserve page scrolling at either end.