OpenAI President Greg Brockman, who helped launch the artificial intelligence developer and has been key to developing ChatGPT and other core products, has resigned, according to a person with knowledge of the situation. The move came after the company’s board fired CEO Sam Altman earlier Friday.

Brockman was a member of the six-member board that fired Altman, after which the board said in a blog post that Altman had not been candid with them. The blog post said Brockman would step down from his role as chairman of the OpenAI board but that he would stay on in an operating role. But by Friday afternoon, he decided to resign.