https://openai.com/o1 

We’re releasing a preview of OpenAI o1—a new series of AI models designed to spend more time thinking before they respond. This new series of AI models can reason through complex tasks and solve harder problems than previous models in science, coding, and math. 

Rolling out today in ChatGPT to all Plus and Team users, and in the API for developers on tier 5: www.openai.com...