GPT-6.1 Sol arrives in Codex

What changed

GPT-6.1 Sol (gpt-6.1-sol) was added to Codex and ChatGPT Work for long-running work across code, apps and documents. Availability depends on plan, client and workspace settings, and Enterprise and Edu need admin enablement. OpenAI’s models page now recommends it as the GPT-5.5 replacement on Plus, Pro, Business, Enterprise and Edu.

Who it affects

Paid ChatGPT plans, depending on plan, client and workspace settings.

What to do

Select gpt-6.1-sol, and switch any GPT-5.5 configs to it.

Source: https://learn.chatgpt.com/docs/changelog#codex-2026-09-29-gpt-61-sol