GPT-5.5 has been deployed to Codex, but OpenAI has not made an official announcement yet.

According to Cognizant Beating monitoring, GPT-5.5 has appeared in the model selector dropdown of OpenAI Codex, located at the top of the list.

OpenAI has not yet released any official announcement or documentation regarding GPT-5.5.

Earlier, several media outlets reported that the next-generation cutting-edge model at OpenAI, internally codenamed "Spud," completed pre-training at the end of March. It is widely speculated that its official name will be GPT-5.5 or GPT-6, with an expected release in the second quarter.