Codex macOS app main process spikes to 250% CPU during long local development session

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

26.506.31421

What subscription do you have?

pro

What platform is your computer?

_No response_

What issue are you seeing?

Environment

• App: Codex Desktop App
• OS: macOS
• Codex app version visible in process args: 26.506.31421
• Workflow: Long-running local development session with local server, browser/Playwright verification, large chat context, and screenshots.

Problem

Codex Desktop App CPU usage becomes extremely high during an active session. Opening a new chat often temporarily resolves the issue, suggesting the issue is tied to long session state, renderer/app process state, or accumulated context/UI work.

Observed CPU snapshot

From ps -axo pid,ppid,pcpu,pmem,etime,command | sort -k3 -nr | head -30:

• /Applications/Codex.app/Contents/MacOS/Codex: 249.4% CPU
• Codex Helper (Renderer): 15.2% CPU
• Codex Helper --type=gpu-process: 13.8% CPU
• codex app-server --analytics-default-enabled: 9.4% CPU

The project server was not the cause:

• src/app.py: 0.0% CPU
• No leftover high-CPU Playwright/Chrome process related to the test
• Local firmware updater service stayed idle

Expected behavior

Codex should not sustain extremely high CPU usage during a normal long coding session. If a browser/renderer/session becomes expensive, it should recover, throttle, or provide a way to reset that part without forcing a new chat or app restart.

Actual behavior

Codex main process spikes above 200% CPU. User frequently has to start a new chat or restart Codex to recover performance.

Notes

This is reproducible during long UI development sessions with:

• large conversation history
• screenshots/images in thread
• local browser verification
• repeated file edits and test runs

What steps can reproduce the bug?

Use Codex macOS app for a long local coding session with many screenshots, file edits, tests, and localhost browser checks in the same chat. After several hours, Codex.app main process spikes to ~250% CPU while the local project server is idle. Starting a new chat or restarting Codex temporarily fixes it.

What is the expected behavior?

_No response_

Additional information

_No response_