OpenAI Codex will be powered by the next-generation flagship model, GPT-5.6 Sol Ultra.

According to DataBeat monitoring, Thibault Sottiaux, the Head of Core Products at OpenAI, has confirmed on social media that the next-generation flagship model, GPT-5.6 Sol, will integrate Codex.

Previously, some users complained that not including GPT-5.5 Pro in Codex was a major oversight by OpenAI. If GPT-5.6 Ultra can be integrated, developers may not even need to pay for Claude anymore. Sottiaux promptly confirmed publicly that the Ultra version is indeed planned for Codex.