High CPU usage / overheating on macOS when running scripts or making edits in Codex app #18481

Describe the bug

On macOS, running scripts or performing edits through the Codex desktop app causes sustained high CPU usage and noticeable overheating (fans ramping up, laptop becomes hot to the touch). The issue occurs both during active agent runs and sometimes persists after tasks complete.

Environment

• Codex.app version: 26.415.30602 (build 1773)
• codex-cli version: 0.121.0
• macOS: 26.3.1 (build 25D771280a)
• Hardware: MacBook Pro M3 Pro (Mac15,6), 11-core CPU (5P + 6E), 18 GB RAM

Steps to reproduce

1. Open Codex.app
2. Start a session that runs shell scripts or applies multiple file edits
3. Observe CPU usage in Activity Monitor and chassis temperature

Expected behavior

CPU usage should stay proportional to active work, and idle/background periods should return to low usage without sustained thermal load.

Actual behavior

• Sustained high CPU on Codex-related processes during script execution / edits
• Fans ramp up; laptop noticeably overheats
• Behavior occurs even for relatively small tasks

Additional context

Multiple Codex-related processes are typically resident (main app, SkyComputerUseService, several SkyComputerUseClient mcp instances). Happy to run powermetrics / sample / attach spindumps if helpful — please let me know which diagnostics would be most useful.