xAI releases Grok V9-Medium: 1.5 trillion parameters trained on real developer sessions

My take: On June 16, xAI released Grok V9-Medium, a 1.5 trillion-parameter coding-focused model that is three times the size of its previous production model. What sets it apart: it was trained on real developer sessions from Cursor, not just public GitHub repositories, giving it exposure to live workflows instead of static code. The timing is no accident: it arrives right after SpaceX acquired Cursor for $60 billion, and the fight over AI coding tools is at its most intense.