SAN FRANCISCO — Daniela Amodei has an energy that’s hard to place — warm, unhurried, immediately present. She swept into a sunlit room on the ground floor of Anthropic’s headquarters in December, sat down, and immediately apologized for her mug.

“Is my, like, gigantic novelty mug going to be distracting if I have it?” she said. “I’ll defer to the wise camera people in terms of what’s in the shot.”

It was a disarming kind of normal for someone operating at this level.

Five years ago, she and her brother, Anthropic CEO Dario Amodei, led an exodus from OpenAI.

They took a core group of senior researchers and started Anthropic with a contrarian bet: That safety and business success weren’t in tension, that the real money wasn’t in viral consumer products, and that the artificial intelligence race would be won by the company that knew when to slow down.