This week, SpaceXAI, created by Elon Musk, has released its most important update ever since the company has agreed to purchase Cursor for 60 billion dollars back in June. The most impressive thing about Grok 4.5 is that it has been trained using Cursor’s dataset which consists of trillions of tokens collected from the actual users. These include code bases as well as interactions between developers and agents. It is quite a different release from what we have seen before.
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There are some aspects about this release that you need to know to understand the significance of it. In June, SpaceXAI has announced that it will purchase an AI coding startup called Cursor for 60 billion dollars. The startup itself has been developing an in-house model which is specifically designed for coding – Composer 2.5. But Grok 4.5 goes way further than that. It includes STEM and research paper tasks together with all the Cursor data which allows the model to cover such areas as finance, law and general tasks. According to Elon Musk, “it’s an Opus-class model, but faster, more token-efficient and lower cost”.
Does this signify Grok making its way into the mainstream of vibe coding? It doesn’t, at least not yet, and the narrative can use some challenging here. Grok 4.5 is not taking any place from GPT-5.6, Opus 4.8, and Cursor’s own Composer 2.5 in the pool; rather, it receives default visibility: double usage limits in the first week, availability on desktop, web, iOS, CLI, and the SDK, so millions of real-life developers who don’t necessarily seek Grok 4.5 out will encounter it. This might be distribution, but it’s often the first step toward mainstream.
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It should be noted right away that there is a catch regarding the benchmark charts. An accidental inclusion of the previous version of the codebase of the same company in the training dataset of Grok 4.5 made the score on the internal benchmark of Cursor significantly higher, and the company decided to exclude the metric altogether from public comparison. Moreover, some of the metrics used to demonstrate superiority to the competition are reported by the company itself and/or obtained in the internal testing of Cursor. None of that erases what’s genuinely interesting here, but it does mean the “beats Opus 4.8” framing floating around deserves a raised eyebrow rather than a retweet.
The more durable story is structural. SpaceXAI trained this model partly on the same compute it rents out to Anthropic and Google for close to a billion dollars a month, and now owns the IDE where a meaningful chunk of professional coding actually happens. Musk has built himself a data flywheel: buy the tool, train on the usage, ship the model back into the tool. Whether Grok 4.5 wins developers on merit is still an open question. Whether Musk has built the pipes to keep trying is not.
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