The ChatGPT app and the Codex CLI use the same setup. Point Codex's built-in
OpenAI provider at Sleev by adding this line to the top of ~/.codex/config.toml, before any [section]:
This URL is for signing in with your ChatGPT account. If you use an OpenAI API
key, end it with /sleev/chatgpt/openai/v1 instead.
Remove any model_provider line from the file. Codex only applies openai_base_url to its built-in OpenAI provider.