Codex CLI startup regressed in 0.137.0

Summary

I've noticed that with the latest update to v0.137.0 the startup of Codex CLI takes a significant amount of time. We are talking over 5 seconds. To test what is going on, I timed codex mcp list as test for this, but the same slowdown is experienced when entering TUI, across last three version (0.135.0 - 0.137.0). There appears to be a startup-time regression in Codex CLI 0.137.0.

On my machine, codex mcp list takes about 1.8s - 1.9s (which is a lot) on 0.135.0 and 0.136.0, but about 5.5s - 6.9s on 0.137.0 .

The command output is the same across versions, but total wall-clock time is significantly worse.

### Reproduction

I tested with: time codex mcp list

and switched versions with:

npm install -g @openai/codex@0.136.0
npm install -g @openai/codex@0.135.0
npm install -g @openai/codex

Results

| Version | Run | Command | User | System | CPU | Total |
|---|---|---|---:|---:|---:|---:|
| 0.137.0 / latest | Initial | codex mcp list | 0.16s | 0.06s | 3% | 5.529s |
| 0.137.0 / latest | Later retest | codex mcp list | 0.16s | 0.07s | 3% | 6.915s |
| 0.136.0 | Initial | codex mcp list | 0.16s | 0.05s | 10% | 1.944s |
| 0.135.0 | Initial | codex mcp list | 0.14s | 0.05s | 10% | 1.841s |

Expected behavior

codex mcp list should have roughly similar startup latency to 0.135.0 / 0.136.0, unless there was an intentional change.

Actual behavior

0.137.0 adds roughly 3.5s - 5s of extra wall-clock time for this command on the same machine.

Environment

• Codex CLI versions tested:
• 0.135.0
• 0.136.0
• 0.137.0 / latest

• Install method: npm install -g @openai/codex
• OS: macOS (Darwin 25.5.0 arm64 arm)
• Shell: zsh

Notes

This looks like a startup/init regression rather than actual command work, since user/system CPU time stays low while wall-clock time increases a lot.