[derangedHorse]

For hard problems you’ll have to use the GPT 5.5 pro model (available via api if you don’t want to spend $100 on the monthly subscription)

[bottlepalm]

I have that but don’t see any ‘pro’ option.

[ValentineC]

GPT 5.5 Pro is only in chat/API, not Codex.

[Supermancho]

From https://openai.com/index/introducing-gpt-5-5/

In Codex, GPT‑5.5 is available for Plus, Pro, Business, Enterprise, Edu, and Go plans with a 400K context window.

[artdigital]

He’s talking about “gpt-5.5-pro”. This model is not part of the subscription plans in codex. It’s a different model than gpt-5.5-xhigh

You can use Pro on the web if you’re on the Pro plan but not in Codex

[trollbridge]

It's just the $20 a month sub (for chat), or else use the API.