xAI launches Grok 4.5 in private beta with SpaceX and Tesla, powered by a 1.5 trillion parameter V9 model that rivals Anthropic's Claude Opus.

xAI's Grok 4.5, a 1.5 trillion parameter model built on V9 with Cursor data, enters private beta at SpaceX and Tesla with performance rivaling Anthropic's

Musk said reinforcement learning is continuing to improve the model and that "Grok Build," xAI's coding-agent harness, is being refined daily. He framed the SpaceX and Tesla…