OpenAI Founding Member Andrej Karpathy Joins Anthropic, Returns to LLM Research

OpenAI was founded in 2015, and Dario Amodei joined in 2016 before becoming vice president of research. He later fell out with CEO Sam Altman over model development, safety governance and the distribution of power. Dario, his sister Daniela and others founded Anthropic in 2021. The company raised $30 billion at a $380 billion valuation in February 2026, turning a clash of principles into a broader contest over the direction of AI.

A Wall Street Journal investigation published on March 28, 2026, traced nearly a decade of conflict between the two sides. The latest flashpoint came on February 26, when Anthropic rejected a U.S. Department of Defense demand to make Claude available for “all lawful purposes.” It insisted on retaining bans on mass domestic surveillance and fully autonomous weapons, putting a $200 million contract at risk of cancellation. OpenAI secured a defense agreement with similar guardrails the next day, after which Amodei accused the company’s account of being “a complete and utter lie.”