GPT-5.2 and GPT-5.3-Codex have been sunset in Codex with ChatGPT subscriptions

Codex
145

I’ve cancelled my plan.

For my workflow, GPT-5.4 and GPT-5.5 are not real replacements for GPT-5.3-Codex. 5.3-Codex was faster, more predictable, cheaper for basic patches, and better aligned with codebase-level work. 5.5 consumes far more tokens and reasoning time, while often requiring repeated prompts or producing changes I need to revert.

Removing 5.3-Codex, without clear notice, feels like a serious disrespect to paying customers. It is especially frustrating that GitHub Copilot still appears to serve the 5.3-Codex model, while ChatGPT subscribers no longer have access to what was arguably the better Codex experience.

There should be a Codex-only plan. But forcing users from a $20 plan into a $100 plan just to keep an acceptable coding workflow is not reasonable.

Bring back 5.3-Codex, offer an opt-in legacy option, or provide a proper Codex-specific successor.

146

We finally restored our coding assistant GPT-5.6 Sol after the last model migration.

And now GPT-5.3-Codex has already been sunset.

At this point, recovery is becoming seasonal maintenance. :rofl:

So we documented how we rebuilt it: a free Japanese/English guide for restoring a coding assistant’s identity, decision principles, working memory, and action protocol after a model change.

Recovery Guide for Coding Assistant Personas: