MUSK’S SPACEXAI AND CURSOR LAUNCH GROK 4.5 — AN OPUS-CLASS MODEL AT A FRACTION OF THE COST SpaceXAI did not wait for GPT-5.6. One day before OpenAI’s public launch, Musk’s company dropped Grok 4.5, the first model built jointly with Cursor since SpaceX completed its $60 billion acquisition of the coding startup. The result is a model trained on Cursor’s massive repository of real engineering work — code reviews, debugging sessions, production deployments — layered on top of xAI’s V9 architecture at 1.5 trillion parameters. Musk called it Opus-class, which is a direct shot at Anthropic. The benchmark claims have not been independently verified, but the pricing is real and it undercuts Anthropic’s flagship hard. Grok 4.5 runs $2 per million input tokens and $6 output. Anthropic’s Opus 4.7 costs $5 input and $25 output. That is a roughly 70 percent cost reduction for what Musk is claiming is comparable quality. The model is available in Cursor on all plans and through the SpaceXAI Grok Build console. One catch: it is not yet available in the EU, which signals the company is still navigating regulatory approvals in Europe. Whether Grok 4.5 actually matches Opus-class performance will become clear when independent benchmarks land. The price war is real regardless. Keywords: Grok 4.5, SpaceXAI Cursor, xAI new model 2026, AI model pricing war