Pick a model for the run
interactive sessions
// what it does
-m/--model overrides the configured model for one run. The current family is gpt-5.6-sol (flagship, hardest coding and security work), gpt-5.6-terra (balanced everyday), and gpt-5.6-luna (fastest and cheapest). Set a default with model= in config.toml, or switch mid-session with /model, which also sets reasoning effort.
// shell
$ codex -m gpt-5.6-sol "refactor the auth module"$ codex -m gpt-5.6-luna "quick pass over the README"// gotcha
gpt-5.2 and gpt-5.3-codex are deprecated for ChatGPT sign-in — a config file or -m that still names them fails, so update to a gpt-5.6 model.