NOTE: There is currently a breaking issue affecting the current version of Codex CLI and the CBorg API Server. We are monitoring the situation and will update this page when it is fixde.

1. Configure OpenAI keys

export OPENAI_API_KEY=$CBORG_API_KEY
export OPENAI_BASE_URL=https://api.cborg.lbl.gov

2. Restart shell and verify key settings

env | grep OPENAI

3. Start Codex

cd my-project
codex

Note: The default model is o4-mini.

The gpt-5-codex model is also supported and is recommended for best performance.

The model can be configured in a .codex file or passing the –model argument., e.g.

alias codex=codex -m gpt-5-codex

For more information see OpenAI Codex Github