Codex Desktop: Computer Use duplicates physical keyboard and paste events system-wide on macOS

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

26.727.51351 (build 6119)

What subscription do you have?

ChatGPT paid subscription (exact tier is not exposed in the local diagnostics used for this report)

What platform is your computer?

Darwin 25.6.0 arm64 arm (macOS 26.6, build 25G72)

What issue are you seeing?

While Codex Computer Use is active and its picture-in-picture preview is visible, every physical keyboard event can be delivered twice system-wide. For example, pressing y once produces yy. Pressing Cmd+V once pastes twice, including creating two identical screenshot attachments in Codex.

The behavior affects:

• the built-in Mac keyboard and an external keyboard;
• every tested input source, including the macOS ABC source and a third-party Chinese IME;
• Codex, TextEdit, and other applications;
• both typing and keyboard shortcuts such as Cmd+V.

Stopping the active Computer Use operation and closing its preview immediately restores normal input. Re-enabling Computer Use in another Codex thread makes the problem recur.

This is not keyboard chatter or an IME-specific problem. In two observed duplicate-paste events, each pair of generated attachment files had the same byte size, SHA-256 hash, and creation second, showing that one Cmd+V action was handled twice.

What steps can reproduce the bug?

1. Open Codex Desktop on macOS.
2. Start Computer Use in any thread and let it control another desktop application (in this case, Claude Code).
3. While the Computer Use picture-in-picture preview remains active, focus a normal text field in Codex or another app.
4. Press a letter once. Intermittently but repeatedly, one keypress produces two identical letters.
5. Press Cmd+V once with an image in the clipboard. Two identical attachments may be created.
6. Stop Computer Use and close the preview. Input immediately returns to one event per physical action.
7. Start Computer Use again. The duplication returns.

The issue reproduced across multiple Codex threads and applications. It is timing-dependent, so a very short synthetic Computer Use test may not always trigger it, but normal Computer Use sessions reproduce it repeatedly.

What is the expected behavior?

Computer Use must not duplicate or forward the user's physical keyboard events. One physical keypress or keyboard shortcut should be delivered exactly once, and ending a Computer Use session should reliably remove all associated keyboard event taps.

Additional information

During a live faulty state, CGGetEventTapList showed the ChatGPT Computer Use process with five event taps, including three enabled active keyboard filters for keyDown/keyUp/flagsChanged. When the preview disappeared and input recovered, that process was absent from the event-tap list.

The helper path was:

~/.codex/computer-use/Codex Computer Use.app/Contents/MacOS/SkyComputerUseService

The same SkyComputerUseService process had remained alive since the previous day. Sending SIGTERM did not stop it. SIGKILL removed the old PID, but a new orphaned instance (PPID 1) was immediately spawned while another Codex thread was still using Computer Use. Telling that thread to stop Computer Use restored normal input.

This may be related to #25744 (Computer Use helper accumulation/HID lag), but this report is specifically about duplicated physical keyboard and paste events. It may also interact with the cross-thread Computer Use behavior in #36829.

No private screenshots are attached because the PiP preview contains user task content, but redacted diagnostics can be provided if needed.