OpenAI president and co-founder Greg Brockman has resigned, he announced Friday, hours after the company’s board abruptly fired CEO Sam Altman and stripped Brockman of his chairman role.

Brockman said that chief scientist Ilya Sutskever informed Altman about a Friday noon call on Thursday evening, with the rest of the management team learning shortly after—except CTO Mira Murati, who was told the night before. Murati has been named interim CEO.

“Based on today’s news, i quit,” Brockman wrote in a message to the OpenAI team, which he also posted on X. He said the board wanted him to stay but he chose to leave, saddened by their direction.

The company said Altman was fired after a review found he was “not consistently candid in his communications” with the board. Neither OpenAI nor Microsoft—which owns roughly half the startup—have explained further.

Silicon Valley is in shock: Altman has been the public face of the AI boom, and his ouster, paired with Brockman’s departure, leaves the future of the company uncertain. Gartner analyst Arun Chandrasekaran said the departure is “indeed shocking” but noted OpenAI has a “deep bench of technical leaders.” Forrester analyst Rowan Curran speculated the transition is about the individual, not the technology.