Since GPT-5.4, we’ve unified Codex and the main model into a single system, so there’s no separate coding line anymore.

GPT-5.5 takes this further, with strong gains in agentic coding, computer use, and any task on a computer.

— Romain Huet (https://twitter.com/romainhuet/status/2047955381578838357), confirming OpenAI won’t release a GPT-5.5-Codex model

Tags: generative-ai (https://simonwillison.net/tags/generative-ai), gpt (https://simonwillison.net/tags/gpt), openai (https://simonwillison.net/tags/openai), ai (https://simonwillison.net/tags/ai), llms (https://simonwillison.net/tags/llms)