SpaceXAI, Elon Musk's company, launched Grok 4.5, its smartest model yet and its first release since going public and acquiring the AI coding startup Cursor. The new model is pitched as a coding and agentic-work tool, with Musk stating it is "maximally truth-seeking" compared to competitors. The company says Grok 4.5, trained alongside Cursor, outperforms comparable models on engineering and knowledge work. "It is an Opus-class model, but faster, more token-efficient and lower cost," wrote Musk on X. A chart says the model outperforms Opus 4.8 on several key benchmarks. Grok 4.5 is available today in Grok Build, in Cursor on all plans, and from the SpaceXAI console, but not yet in the EU. SpaceXAI claims it outperforms some OpenAI and Anthropic models on speed, price and performance, but not the largest, latest models from those competitors. Grok 4.5 is priced at $2 per million input tokens and $6 per million output tokens; Claude's Opus 4.8 is $5 per million input tokens and $25 per million output tokens; OpenAI's GPT 5.6 Luna is $1 input / $6 output. The model was trained using the same compute capacity SpaceXAI leases to competitors Anthropic and Google. SpaceXAI is positioning Grok as a serious contender for business use that can be cheaper than