Elon Musk on Sunday announced that Grok 4.5, built on xAI's 1.5-trillion-parameter V9 foundation model, has entered private beta testing at SpaceX and Tesla. The model, also trained on additional data from SpaceX's newly acquired startup Cursor, shows "performance close to, perhaps exceeding" Claude Opus, Musk said. "New models will be released by SpaceX every month this year," he added.