High idle CPU (25%) in Codex IDE extension on Positron: Electron window renderer consumes CPU after opening Codex panel

What version of the IDE extension are you using?

26.5422.30944

What subscription do you have?

Plus

Which IDE are you using?

Positron

What platform is your computer?

Microsoft Windows NT 10.0.19045.0 x64

What issue are you seeing?

Summary

The Codex IDE extension causes persistent idle CPU usage (25%) in Positron on Windows after opening the Codex panel. The CPU usage appears under Positron's Electron renderer process named window, not primarily under Extension Host. Reverting the Codex extension to an older version from roughly one month ago fixes the issue completely.

This looks like a regression in the recent Codex IDE extension UI/webview path, possibly a render loop, polling loop, or retained webview state issue.

Environment

• OS: Windows
• Editor: Positron, a VS Code fork
• Workspace: local Windows folder, C:\Users\UserName\Documents\Positron_scripts
• Codex extension: openai.chatgpt
• Bad versions tested: 26.5422.30944 (most recent) , behaviour noticed with 26.417.40842 from one week ago
• Good version: older extension version 0.4.79
• Runtime mode tested:
• WSL mode
• Native Windows mode

Actual Behavior

When Codex is enabled/opened in Positron, idle CPU rises and stays high.

Observed behavior:

• Codex disabled: CPU drops to approximately 0%.
• Recent Codex extension, WSL mode: CPU rises to about 25% while idle after opening Codex.
• Recent Codex extension, native Windows mode: CPU rises to about 48% while idle (but the extension is basically disabled because I have not set up the Windows mode - no chat history, model options etc).
• Older Codex extension from about one months ago: no idle CPU usage problem.
• Older Codex extension from two weeks ago (26.409.20454) takes up to 48% cpu usage when Codex extension automatically loads on start, but drops to 0% only after I start a new chat.

In Positron's Process Explorer, the main CPU consumer is a process named window, with another entry window[1] corresponding to the Process Explorer window itself. The issue appears to be in the editor renderer/webview side rather than in Extension Host.

What steps can reproduce the bug?

Reproduction Steps

1. Open Positron on Windows.
2. Install/use the recent Codex IDE extension.
3. Open a normal local workspace.
4. Open the Codex extension/sidebar.
5. Leave Codex idle, with no active agent/task running.
6. Observe CPU usage in Task Manager and/or Positron Process Explorer.
7. Disable Codex or revert to an older Codex extension version.
8. Observe CPU usage return to idle/near-zero.

Things Tried

The following did not fix the issue:

• Starting a new Codex chat/thread.
• Disabling Codex TODO CodeLens:
• chatgpt.commentCodeLensEnabled: false
• Resetting/new chat did not resolve the issue.

Reverting the Codex extension to an older version from around one month ago did fix the issue.

What is the expected behavior?

Opening the Codex sidebar/panel should not cause persistent idle CPU usage when no Codex task is running.

Additional information

The same issue seems to happen in VS Code, some reddit users noted two days ago: https://www.reddit.com/r/codex/comments/1suvg6s/has_anyone_noticed_codex_in_vs_code_using_high/