codex app cpu 100%

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

26.602.40724

What subscription do you have?

gpt plus

What platform is your computer?

mac os

What issue are you seeing?

The persisted UI state in ~/.codex/.codex-global-state.json conflicted with
the current Codex App and existing local data when loaded together. This
triggered a JavaScript main-thread loop in the Renderer, preventing the page
from loading and keeping CPU usage near 100%.

On June 8, 2026, Codex App showed the following symptoms:

• The application launched, but the page never finished loading.
• One Codex (Renderer) process continuously consumed approximately 99% to 100% CPU.
• Force-quitting and reopening the application reproduced the issue.
• Resetting the UI state restored the application, but the sidebar workspace or conversation list might need to be recovered.

What steps can reproduce the bug?

copy long text to code app

What is the expected behavior?

_No response_

Additional information

The Codex App global UI state file, ~/.codex/.codex-global-state.json, became invalid or incompatible with the existing local data. This file stores workspace information, page state, and composer drafts.

When Codex loaded the old UI state, the Codex (Renderer) JavaScript main thread entered an infinite loop. As a result, the Renderer continuously consumed approximately 100% CPU and the page could not finish loading.

The investigation confirmed that network requests, the Codex backend service, plugins, caches, and SQLite databases were functioning normally. The old UI state contained an abnormally large 4,175-character composer draft, which was the most suspicious trigger, although it was not proven to be the sole cause.

The issue was resolved by backing up and resetting .codex-global-state.json, allowing Codex to generate a clean UI state file. After the reset, Renderer CPU usage dropped from approximately 100% to 0%, and the application loaded normally.

The complete conversation history was not deleted. It remains stored in ~/.codex/state_5.sqlite and ~/.codex/sessions/.

After resetting the UI state, the sidebar conversation list may temporarily appear empty because the workspace-to-thread UI mappings were reset. Reopening previously used project directories should allow Codex to rebuild the sidebar conversation list automatically.

Do not restore the entire old .codex-global-state.json file, as this may reintroduce the high-CPU issue. If manual recovery is required, restore only the workspace and thread mapping fields while excluding electron-persisted-atom-state.