Desktop: Computer Use / Browser Use PiP paints large black box when hovering close (X) control

What version of the Codex App are you using?

26.707.51957 (build 5175)

What subscription do you have?

N/A (reported with repro screenshots)

Which OS are you seeing the problem on?

macOS 15.7.7 (24G720), Apple Silicon

Bug summary

When Codex shows a floating Computer Use / Browser Use PiP overlay (e.g. iOS Simulator preview or browser use live view), hovering the close (X) control paints a large solid black rectangle over the top of the preview. The X / pop-out controls sit on top of that black box and the preview is partially obscured.

This is a pure UI glitch on the remote-hosted PiP control chrome — dismissing still works, but the hover feedback is broken.

Steps to reproduce

1. Open Codex Desktop on macOS.
2. Start a task that surfaces a live overlay:

• Computer Use with iOS Simulator, or
• Browser Use PiP / live screenshot overlay.

1. Wait until the floating preview appears (phone frame / browser snapshot).
2. Move the cursor over the overlay so the hide (X) and pop-out controls appear.
3. Hover specifically over the X close control.

Expected

Hover on X should show a small, translucent / frosted control highlight (or none), without covering a large region of the preview with opaque black.

Actual

A large solid black rectangular region appears over the top of the PiP (including device chrome). White X + pop-out icons remain visible on top of the black box. Moving the cursor away restores the normal soft control fog / shadow.

Screenshots

1. Normal overlay (no hover on X):

!Normal PiP overlay

2. Hovering the X control — large black box (bug):

!Black box on X hover

3. Controls visible with soft circular shadow (hover near phone, not on X):

!Soft control shadow

4. Hover near controls, black box not fully triggered:

!Hover near controls

Technical investigation notes (for maintainers)

This overlay is not implemented in the public openai/codex CLI sources. On macOS it is rendered by the Desktop app’s remote-hosted PiP stack:

| Layer | Location |
| --- | --- |
| Native PiP host | Contents/Resources/native/sky.node |
| Controller | PIPStackController |
| Content view | PIPStackContentView (updateHoverFromCurrentMouseLocation, updateHoverAtContentPoint:) |
| Close control | _hideControlLayer / _hideControlIconLayer / _hideControlFrame |
| Pop-out control | _placementControlLayer + assets remote-hosted-pip/pop-out-window-egg@3x.png |
| Control material | _controlFogContainerLayer, _controlFogBackdropLayer, _controlFogBlurMaskSourceLayer, _controlFogDynamicShadowBackdropLayer* |
| Per-item hover | PIPStackItem._hoverOverlayLayer |

Likely failure mode: when hoveredControlIdentifier becomes the hide (X) control, either:

1. _hoverOverlayLayer / control-fog shape frame (_controlFogShapeFrame) expands to a large solid black fill instead of a small frosted pill, or
2. the dynamic shadow / blur-mask (_controlFogDynamicShadowBackdrop*, CABackdropLayer / CIGaussianBlur) fails and falls back to an opaque black backdrop while control icons are forced light (setControlIconWhiteAmount: / contrast sampling).

Electron glue also references this stack via:

• remote-hosted-pip-* IPC messages
• browser-use-pip / codex/toolSurface presentation upsert
• feature flag cuaPIP

A public PR against openai/codex cannot fix this: the bug lives in the closed-source Desktop native module (sky.node / PIP stack), not the open-source CLI.

Suggested fix direction (internal)

1. Reproduce with Computer Use PiP + Simulator (or Browser Use PiP) on macOS.
2. In PIPStackController, inspect setHoveredControlIdentifier: / updateHoverAtContentPoint: when identifier == hide control.
3. Verify _controlFogShapeFrame and fog mask layers stay sized to the control chrome, not a large top rect.
4. Ensure backdrop/blur failure does not paint opaque blackColor under the full fog container.
5. Confirm _hoverOverlayLayer on PIPStackItem is not incorrectly sized when only the hide control is hovered.

Impact

• Blocks clean interaction with live PiP previews (Simulator / Browser Use).
• Looks like a serious rendering failure; easy to hit during normal “close the overlay” usage.
• Does not appear to crash or break dismiss functionality, but is highly visible.

Related (different bugs)

Other “black box/overlay” reports exist for plugins page / pets / Windows chrome, but none describe PiP close-control hover specifically. Happy to close as duplicate if an internal ticket already tracks the control-fog hover regression.