How to make Codex use the macOS or Windows system proxy with respect_system_proxy

By default, Codex CLI ignores the macOS and Windows system proxy settings (respect_system_proxy is off). On a corporate network where traffic has to go through the system proxy, Codex may fail to reach the model provider. Starting with 0.167.0, you can turn this on from the experimental features menu.

1. Update Codex to 0.167.0 or later.

npm install -g @openai/codex@0.167.0

1. Inside Codex, open /experimental, check System proxy with Space, and press Enter to save. To turn it on straight from the terminal, run:

codex features enable respect_system_proxy

1. Restart Codex after changing the setting.

If codex doctor reports "provider is unreachable" and says a macOS system proxy is configured but unused, this is the fix. Codex itself suggests checking with your administrator first if you're on a company network. It's still experimental, so it appears only in the release notes and the PR, not in the docs yet.