Windows Computer Use cannot control native Windows apps — cua.getApp is not a function

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

26.831.21537

What subscription do you have?

ChatGPT Plus

What platform is your computer?

Microsoft Windows NT 10.0.26200.0 x64

What issue are you seeing?

Windows Computer Use is enabled, but native Windows application control is not functioning.

The Computer Use plugin is installed and enabled. Browser interaction through Computer Use is still functional in the “Try now” demo: it successfully opened YouTube, searched for a video, and started playback.

However, Computer Use cannot detect or control native Windows applications such as Notepad.

I reproduced this in a completely new, empty Codex conversation with no project or workspace loaded.

Actual behavior

• The Windows application list is empty.
• getApp fails with the following error:

cua.getApp is not a function

• The Computer Use tool/API documentation exposed in the Codex session lists getApp and listApps, but the actual runtime does not expose a usable getApp function.
• No usable native Windows application-control interface could be found.
• Native Windows applications such as Notepad cannot be controlled.
• Browser interaction through Computer Use is still functional in the “Try now” demo: it successfully opened YouTube, searched for a video, and started playback.

Expected behavior

Computer Use should be able to:

1. Enumerate available Windows applications.
2. Locate and open native Windows applications such as Notepad.
3. Interact with those applications through Windows Computer Use.

Troubleshooting already performed

I have already:

• Disabled the Computer Use plugin.
• Waited several seconds.
• Re-enabled the Computer Use plugin.
• Fully shut down Windows.
• Waited approximately one minute.
• Restarted Windows.
• Restarted Codex.
• Created a completely new empty Codex conversation.
• Did not load any project, workspace, or unrelated files.
• Retested Computer Use using Windows Notepad.

The issue remains exactly the same.

Important observation

This does not appear to be a complete Computer Use failure.

Browser interaction through Computer Use is still functional in the “Try now” demo: it successfully opened YouTube, searched for a video, and started playback.

The failure appears specific to the native Windows application-control layer/runtime.

The UI shows the Computer Use plugin as installed and enabled, but the actual runtime does not expose a usable cua.getApp function.

Please investigate whether the Windows Computer Use native application-control runtime or bridge is failing to load correctly.

Codex feedback report

I have also submitted this issue through the built-in Codex feedback system.

Feedback ID:

no-active-thread-01a0607c-3432-72c0-8c51-2db62c46fee3

What steps can reproduce the bug?

1. Open the Codex Windows app.

2. Confirm that the Computer Use plugin is installed and enabled.

3. Start a completely new, empty Codex conversation without loading any project or workspace.

4. Ask Computer Use to open Windows Notepad and type a short test message.

5. Computer Use fails to enumerate native Windows applications. The Windows application list is empty.

6. Attempting to access the native Windows application interface results in:

cua.getApp is not a function

7. The Computer Use tool/API documentation exposed in the Codex session lists getApp and listApps, but the actual runtime does not expose a usable getApp function.

8. As a comparison, run the Computer Use “Try now” demo. Browser interaction through Computer Use is functional in this demo: it successfully opens YouTube, searches for a video, and starts playback.

The problem persists even after disabling and re-enabling the Computer Use plugin, fully shutting down and restarting Windows, restarting Codex, and testing again in a new empty conversation.

Feedback ID:
no-active-thread-01a0607c-3432-72c0-8c51-2db62c46fee3

What is the expected behavior?

When the Computer Use plugin is installed and enabled, Codex should be able to enumerate and control native Windows applications.

In particular, Computer Use should be able to:

1. Detect the available Windows applications.
2. Locate and open Windows Notepad.
3. Send keyboard input to Notepad and interact with it normally.
4. Provide the native Windows application-control functionality represented by getApp and listApps as exposed in the Computer Use tool/API information available to the Codex session.

Browser interaction through Computer Use and native Windows application control should both be functional when the Computer Use plugin is enabled.

Additional information

Codex App version: 26.831.21537

Codex App release date shown in the About dialog:
2026-09-02

Platform:
Microsoft Windows NT 10.0.26200.0 x64

Subscription:
ChatGPT Plus

The Computer Use plugin is visibly installed and enabled in the Codex UI.

The failure appears limited to native Windows application control. Browser interaction through Computer Use is functional in the “Try now” demo: it successfully opened YouTube, searched for a video, and started playback.

The Computer Use tool/API documentation exposed in the Codex session lists getApp and listApps, but the actual runtime does not expose a usable getApp function and the Windows application list remains empty.

This suggests that the Computer Use plugin itself is being loaded at least partially, while the native Windows application-control runtime or bridge may not be loading correctly.

I also submitted the same issue through the built-in Codex feedback system with the current ChatGPT session log included.

Feedback ID:
no-active-thread-01a0607c-3432-72c0-8c51-2db62c46fee3

Start by reproducing the failure in the Codex Windows app with a new empty conversation, the Computer Use plugin enabled, and Notepad; compare native calls with the working Try now browser demo. Inspect the runtime entry points for the documented getApp and listApps interfaces and the Windows native application-control bridge; done means applications enumerate and Notepad can be opened and controlled without the reported error.