John Schulman, OpenAI co-founder and a reinforcement learning researcher central to ChatGPT's development, announced on X that he was leaving OpenAI after about nine years to join Anthropic. He said he wanted to deepen his focus on AI alignment and return to hands-on technical work, and made clear he was not leaving for lack of support for alignment at OpenAI. The same day, co-founder and president Greg Brockman announced an extended leave through the end of the year, drawing attention to the string of founder departures.