[OpenAI to Decommission GPT-5.5 on October 14] According to Deep Tide TechFlow, on September 16, OpenAI announced that starting October 14, GPT-5.5 will no longer be available across all plans of ChatGPT, ChatGPT Work, and Codex. Users utilizing GPT-5.5 in Codex will need to switch to GPT-5.6 Sol or GPT-6 Astra.