Just updated codex to v0.122.0 and got a pleasant surprise!

  1. gpt-5.5 (current)        Latest frontier agentic coding model.

  2. oai-2.1                  Latest frontier agentic coding model.

  3. gpt-5.4                  Latest frontier agentic coding model.

  4. gpt-5.2-codex            Frontier agentic coding model.

  5. arcanine                 Frontier model with legendary appetite for starches

  6. glacier-alpha            intelligence that moves continents

  7. glacier-alpha-block-cy3  ice-cold intelligence

  8. glacier-alpha-block-cy4  ice-cold intelligence

I am a bit puzzled as to what these other models are for.