SpaceXAI has launched Grok 4.5, the first model released since the company rebranded from xAI and the first it trained in collaboration with the AI firm Cursor. The company describes it as its smartest model to date, built specifically to excel at coding, agentic tasks and knowledge work, and claims it outperforms rival leading models on real engineering tasks while generating functional apps from minimal instructions. The launch matters because it marks the debut of a closely watched partnership that could result in SpaceXAI either investing heavily in Cursor or acquiring it outright.

Grok 4.5 was trained across tens of thousands of NVIDIA GB300 GPUs on datasets covering coding, science, engineering and maths, and is priced at $2 per million input tokens and $6 per million output tokens — cheaper than OpenAI's top GPT-5.6 variant. It is now the default model for SpaceXAI's terminal-based coding agent Grok Build, which also handles Excel, PowerPoint and Word tasks, and is available via the SpaceXAI console and across Cursor's plans. The April partnership behind it could see SpaceXAI invest $10 billion in Cursor or buy it for $60 billion later this year, with a decision still pending. The model is not yet accessible in the European Union, where availability is expected in mid-July.