SpaceXAI Prices 1.5T MoE Grok 4.5 at $2 Per Million Input

On July 8, 2026, Cursor and SpaceXAI officially released Grok 4.5. This launch represents the first joint model release since SpaceX acquired the AI coding startup for approximately $60 billion in June. Built on a new foundation architecture, the model targets enterprise developers by heavily undercutting the pricing of competing frontier models while offering comparable reasoning capabilities.

V9 Architecture and Context Limits

Grok 4.5 utilizes the V9 foundation architecture, scaling up to roughly 1.5 trillion parameters. This is a three-fold increase from the 500 billion parameter v8-small production models. The system relies on a Mixture-of-Experts (MoE) design, trained across tens of thousands of NVIDIA GB300 GPUs. For developers building multi-agent systems, the model introduces a notable shift in token efficiency. SpaceXAI claims the new architecture requires half the steps to solve complex reasoning tasks compared to earlier generations.

One distinct change is the context window. Grok 4.5 supports 500K tokens, which is a reduction from the 1 million-plus token windows seen in prior iterations. This constraint suggests a deliberate engineering tradeoff prioritizing inference efficiency and stability over maximum recall length. Practitioners have noted this likely relies on techniques like Grouped Query Attention (GQA) to manage memory bandwidth during high-volume enterprise generation.

Developer and Professional Benchmarks

The model diverges from pure coding optimization, incorporating high-quality STEM research and legal documents alongside trillions of tokens of proprietary Cursor codebase navigation data. This data mix positions the model directly against Anthropic’s Claude Opus 4.8.

On the DeepSWE 1.0 benchmark, Grok 4.5 places strictly in the middle of the frontier pack.

Model	DeepSWE 1.0 Score
Fable	66.10%
GPT-5.5	64.31%
Grok 4.5	62.00%
Claude Opus 4.8	55.75%

Beyond software engineering, Grok 4.5 secured the top rank on Harvey’s Legal Agent Benchmark. This performance profile indicates optimization for long-running, tool-using tasks in finance, data science, and cybersecurity workflows.

Market Positioning and API Pricing

The most aggressive aspect of the release is the cost structure. SpaceXAI priced Grok 4.5 significantly below competing models in the same performance tier. If you need to reduce LLM API costs for high-throughput applications, the economics of this release alter the baseline calculations.

Provider	Model	Input Price (Per 1M)	Output Price (Per 1M)
SpaceXAI	Grok 4.5	$2.00	$6.00
Anthropic	Opus 4.8	$5.00	$25.00
OpenAI	GPT-5.5	$5.00	$30.00

The model is currently live for users in the United States on Cursor, Grok Build, and the SpaceXAI console. Cursor users receive double usage limits during the first week of availability. A public rollout on the X platform is scheduled for July 9, 2026, with European Union access anticipated in mid-July.

The combination of a 1.5 trillion parameter MoE architecture and $2 per million input pricing forces a reevaluation of default routing logic. Developers currently defaulting to Opus 4.8 or GPT-5.5 for agentic workflows should benchmark Grok 4.5 against their specific evals to determine if the 500K context limit accommodates their retrieval strategy.