SpaceXAI launches Grok 4.5, its first built with Cursor's help - Engadget

It’s now the default model for AI coding agent Grok Build. SpaceXAI has launched the first Grok model after its rebranding from xAI and the first one it trained with AI company Cursor. The company says Grok 4.5 is its smartest model yet, built specifically "to excel at coding, agentic tasks and knowledge work." It was trained across tens of thousands of NVIDIA GB300 GPUs on datasets full of coding, science, engineering and math information. The model, SpaceX claims, outdoes other leading models at real engineering tasks and is highly proficient at creating functional apps with minimal instructions. In the example above, Grok 4.5 was able to generate an interactive simulation of the solar system with a single prompt. SpaceXAI also says that it was designed to respond faster than "flash" models and to deliver results "at far lower costs." It's priced at $2 per million input tokens and $6 per million output tokens. For comparison, OpenAI GPT-5.6's most powerful variant, Sol, costs $5 per million input tokens and $30 per million output. However, its most affordable variant, Luna, only costs $1 per million input tokens and $6 per million output. Grok 4.5 is now the default model powerin