SpaceXAI launches Grok 4.5, an 'Opus-class' coding and agentic model

SpaceXAI released Grok 4.5 on July 8, positioning it as a frontier coding and agentic model that Elon Musk described as 'an Opus-class model, but faster, more token-efficient and lower cost.' The company claims wins over Anthropic's Opus 4.8 on several benchmarks across coding, finance, and autonomous tasks. It's built on xAI's new V9 foundation model, trained on tens of thousands of NVIDIA GB300 GPUs, and is now the default in Grok Build (xAI's CLI coding tool) as well as available in the SpaceXAI console and Cursor on all plans.

Third-party validation gave the claims unusual credibility. Perplexity CEO Aravind Srinivas posted he was 'very impressed,' saying Grok 4.5 scored highest on Perplexity's internal WANDR agentic-research benchmark 'at half the price of Claude Opus 4.8 (high)' and even beat their current GLM 5.2 post-training. On Reddit, r/singularity's thread 'Grok-4.5 on par with gpt-5.5-xhigh in coding at half the cost' drew 551 upvotes.

Skepticism persists. Gizmodo and others flagged SpaceXAI tying its brand to a 'problematic' chatbot even as it lands in Cursor, and the 'Opus-class' framing echoes marketing more than independent testing. Musk also teased gaming ambitions, saying Grok 4.5 excels at game-relevant coding with a publicly releasable AI-generated game targeted before end of 2026. The launch coincides with the company's rebrand to SpaceXAI, completing the SpaceX integration. What makes Grok 4.5 notable is the capability-per-dollar pitch landing amid GPT-5.6, Muse Spark, and DeepSeek V4 — the whole frontier converging on the same 'faster, cheaper, agentic' message in a single week.