xAI Launches Grok 4.5 Publicly — Opus-Class Performance at a Quarter of the Price

Summary: xAI released Grok 4.5 publicly on July 8, co-trained with Cursor and targeting real-world engineering tasks. Elon Musk positions it as Opus-class — but at a fraction of the cost.

Key Facts

• Architecture: Built on xAI's 1.5T-parameter V9 foundation, trained across tens of thousands of NVIDIA GB300 GPUs
• Pricing: $2/M input tokens, $6/M output tokens — 76% cheaper than Claude Opus 4.8 ($5/$25)
• Access: Available in Grok Build, Cursor (all plans), and the xAI console API; EU availability expected mid-July
• New integrations: Notion (knowledge management) and Convex (full-stack development) support announced July 9
• A separate private-beta Grok 4.5 continues running internally at SpaceX and Tesla

Why It Matters

The frontier AI competition is shifting from raw benchmark performance toward price-efficiency. Grok 4.5's Cursor co-training signals a move toward real-world developer workflows over synthetic benchmarks. With Anthropic's Fable 5 export-control ban now lifted, all major labs are back in the public market simultaneously — intensifying the pricing race.

Read More

• Introducing Grok 4.5 — xAI Official Blog
• Elon describes it as 'Opus-class model' — TechCrunch