Elon Musk’s xAI moves into OpenAI’s old HQ San Francisco’s Mission district isn’t known for corporate offices, but it’s now home to two of the world’s most well funded AI startups. Elon Musk’s artificial intelligence startup, xAI, recently moved into a new office in the Mission: the same building that served as OpenAI’s headquarters for several years, according to the San Francisco Business Times. Musk’s lawyers recently claimed in a lawsuit that he originally leased the office back when he worked at OpenAI, and has paid the bills ever since. In August, Musk reportedly listed the building for sublease, and OpenAI moved into a new office just four blocks away. Tuesday night, xAI hosted an open house in the new office just hours after OpenAI’s DevDay. xAI employees told one attendee they had just moved into the office Monday, but would spend most of their time in xAI’s Palo Alto office.