xAI Ships Grok 4.5, a Cursor-Trained Coding Model Priced Below Rivals

xAI released Grok 4.5 on July 8, its first model built from the start for software engineering and autonomous agents. The training run was conducted alongside the code editor Cursor. The model is available in Cursor on every plan, in xAI's build tools, and through the application programming interface (API) at $2 per million input tokens and $6 per million output tokens, roughly half the price of comparable frontier models, and it runs at about 80 tokens per second.

The benchmark results are mixed, and they come from xAI's own numbers, which no third party has yet reproduced. On SWE-Bench Pro xAI reports Grok 4.5 at 64.7 percent, behind Anthropic's Opus 4.8 at 69.2 percent and the Fable line above it, though it leads on the longer-horizon SWE Marathon test at 29.0 percent. The more consequential claim is efficiency. xAI says Grok 4.5 completes SWE-Bench Pro tasks using an average of 15,954 output tokens against 67,020 for Opus 4.8. That is a 4.2-times gap, and if it holds outside the vendor's own test setup, it changes the cost of running an agent far more than a few points of accuracy do.

The release comes the same week that Anthropic shipped Sonnet 5 and OpenAI questioned the reliability of SWE-Bench Pro itself, so the headline percentages should be read with the benchmark's known problems in mind. What is verifiable now is the price and the token accounting. The capability ranking is asserted by the vendor and awaits independent runs.