Andrej Karpathy, the former OpenAI co-founder and Tesla AI director who recently joined Anthropic, said X has become so toxic he prefers to hang out on Anthropic's Slack channel. In a post, Karpathy stated he has been on Twitter for almost 2 decades and can say with confidence that it has never been this toxic and Reddit-like, blaming the platform's recommendation algorithm for encouraging hostile behaviour and saying users get "RL'd" by it. Elon Musk responded directly to the post, writing: "We need a complete overhaul of the algorithm." The discussion began after Karpathy argued that Anthropic's newly introduced Claude Tag workflow represents a major shift in how people interact with AI, describing it as a new way of working where the assistant is integrated across tools, memory, compute environments and workflows.