High CPU usage on macOS after updating Codex VS Code extension to 0.50.x+ (0.4.49 works fine)

[voltCore]

What version of Codex is running?

Codex 0.4.50+

What subscription do you have?

ChatGPT Plus

Which model were you using?

GPT-5.2 (also reproduced with GPT-5.1)

What platform is your computer?

MacBook with Apple Silicon (M2) MacOS Tahoe 26.2

What issue are you seeing?

After updating the Codex VS Code extension to version 0.50.x +, CPU usage increases significantly on macOS only when a prompt is sent and Codex starts processing it.

While Codex is actively thinking or generating a response, a single process — "Code Helper (Plagin)" — consumes excessive CPU (up to 300–350%) on Apple Silicon.

The editor remains responsive, but system performance degrades noticeably during prompt processing.

Downgrading the extension to version 0.4.49 resolves the issue completely, with CPU usage remaining at normal levels during prompt execution.

What steps can reproduce the bug?

1. Install Codex VS Code extension version 0.50.x +
2. Launch VS Code on macOS (Apple Silicon)
3. Open any project (JavaScript, Python, or mixed)
4. Open the Codex chat panel and switch agent (Full access) GPT-5.1-Codex-Max High
5. Enter any prompt and send it
6. While Codex is processing the prompt, observe system CPU usage in Activity Monitor

Result:
During prompt processing, the "Code Helper (Plugin)" process spikes to 300–350% CPU and my laptop freezing

Workaround:
Downgrading the extension to version 0.4.49 eliminates the high CPU usage during prompt processing.

What is the expected behavior?

During prompt processing, Codex should utilize system resources efficiently and keep CPU usage within reasonable limits.

CPU usage should scale proportionally to the complexity of the prompt and should not saturate multiple CPU cores on Apple Silicon for simple or medium-sized requests.

Additional information

No response

[github-actions]

Potential duplicates detected. Please review them and close your issue if it is a duplicate.

• Codex app-server stuck at 100% CPU on macOS Apple Silicon when opening VS Code ChatGPT extension #7456
• Codex hung on macOS #7822

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[etraut-openai]

Does this happen for all sessions, or is it just in specific sessions? In your repro steps, you said "enter any prompt". Does it occur only for prompts that result in tool execution? For example, if your prompt is simply "Hi!", does the problem occur?

Please use the /feedback command to upload logs for a session where this occurs and post the thread ID here.

[michaelsthr]

I have the same issue since the update. CPU usage spikes extremly high after prompting anything

[etraut-openai]

@michaelsthr, please use the /feedback command to upload logs for a session where this occurs and post the thread ID here.

[andrewlm6]

Also seeing this issue, thread id below. Seems to be worse on long threads, backing out of it fixes it, even though Codex continues running. M5 Macbook

019bdec8-8c64-7b80-aca9-6123a7bb2268

Update: Latest version fixed this issue.

[doggie1989]

50% cpu ... m4max with 128g ram

[ManuCatZe]

Same Problem here

[tom10271]

Same here, I have to shut down VS Code from time to time to save battery power after getting Codex response. CPU usage stays low before I ask anything for Codex

[ljantos]

Same here, with the same strategy of @tom10271

[vidstige]

VS Code burning through massive amount of CPU. Almost unusable as the battery drains so fast. In the Process Explorer the "window" process name that using the CPU. If I kill that process the Codex panel goes completely gray.

[jinranh]

Same here

[ssinha2103]

Is there any suggestion to fix it urgently ?