SpaceXAI released Grok 4.5, claiming top performance on Harvey's Legal Agent Benchmark and strong capabilities in coding, Excel modeling, and knowledge work. The model was trained on tens of thousands of Nvidia GB300 GPUs, with a focus on data quality and reinforcement learning to reduce thinking tokens. Grok 4.5 is priced at $2 per million input tokens and $6 per million output tokens, significantly undercutting GPT-5.5's $5 input and $30 output rates.