SpaceXAI releases Grok 4.5 at $2/$6 per million tokens, trained with Cursor on NVIDIA GB300 GPUs

SpaceXAI has released Grok 4.5, its first model after rebranding from xAI and the first trained in partnership with AI coding company Cursor. The model is priced at $2 per million input tokens and $6 per million output tokens.

Training infrastructure and focus

According to SpaceXAI, Grok 4.5 was trained across tens of thousands of NVIDIA GB300 GPUs on datasets focused on coding, science, engineering, and math. The company designed the model specifically "to excel at coding, agentic tasks and knowledge work."

SpaceXAI claims Grok 4.5 outperforms other leading models at real engineering tasks and can create functional applications with minimal instructions. The company demonstrated the model generating an interactive solar system simulation from a single prompt.

Pricing comparison

Grok 4.5's pricing positions it between OpenAI's GPT-5.6 variants:

• Grok 4.5: $2 input / $6 output per million tokens
• GPT-5.6 Sol (most powerful): $5 input / $30 output per million tokens
• GPT-5.6 Luna (most affordable): $1 input / $6 output per million tokens

SpaceXAI claims Grok 4.5 responds faster than "flash" models while delivering results "at far lower costs," though specific benchmark comparisons were not provided.

Availability and integration

Grok 4.5 is now the default model for Grok Build, SpaceXAI's terminal-based AI coding agent that handles coding, Excel, PowerPoint, and Word tasks. The model is available through the SpaceXAI console and integrated into all Cursor plans.

The model is not yet accessible in the European Union, with availability expected in mid-July.

SpaceXAI-Cursor partnership details

In April, SpaceXAI and Cursor announced a partnership to develop AI together. The deal structure involves either a $10 billion investment by SpaceXAI into Cursor, or a full acquisition of Cursor for $60 billion "later this year." The companies have not yet disclosed which option they will pursue.

Cursor stated on X: "We've partnered with SpaceXAI to train Grok 4.5. It's our most powerful model yet and the first we've built for more than software engineering."

What this means

Grok 4.5 represents the first concrete output from the SpaceXAI-Cursor partnership and signals SpaceXAI's focus on coding and engineering applications post-rebrand. The pricing undercuts OpenAI's premium GPT-5.6 variant significantly, though it matches the output pricing of OpenAI's budget option. The model's performance claims and "flash" speed assertions require independent verification through benchmarks, as SpaceXAI has not yet published standardized evaluation scores. The pending $10-60 billion deal between SpaceXAI and Cursor makes this release a critical test of their collaborative capabilities.