A 500,000 token window at $2 a million
Grok 4.5 launched on July 8, 2026, the day Cursor published its own launch post and made the model available across its desktop, web, iOS, CLI and SDK products. xAI's announcement calls Grok 4.5 the company's strongest model yet, priced at $2 per million input tokens and $6 per million output tokens, served at 80 tokens per second, and built with a 500,000 token context window. [2][1]
SiliconANGLE covered the release on July 8 and InfoWorld on July 9, and both report the same $2 input and $6 output pricing. SiliconANGLE listed rivals well above those figures: Anthropic's Opus 4.7 and 4.8 at $5 input and $25 output per million tokens, Anthropic's Fable 5 at $10 and $50, and OpenAI's GPT-5.6 Sol at $5 and $30. [4]
Atlas interpretation: xAI's news page carries a July 16 date, eight days after the launch; the same-day Cursor post and press coverage fix the release to July 8, and nothing in the reporting suggests the price or the model changed in between. What is consistent across every account is the pitch: efficiency and price undercutting the frontier rather than beating it outright. InfoWorld's own cost comparison on a coding task put Grok 4.5 at $2.49 per task versus $5.07 for GPT-5.5 in Codex and $11.80 for Fable 5 in Claude Code, a spread that tracks the per-token pricing more closely than any claimed capability edge. [3][2][1]
The first release under the SpaceXAI name
Grok 4.5 shipped as the first frontier model released under the SpaceXAI name. The rebrand was announced in May 2026, about three months after SpaceX said it had acquired xAI, with Elon Musk stating xAI would be dissolved as a separate company and continue as SpaceX's AI division. [5]
xAI's announcement credits Grok 4.5 as having been trained alongside Cursor, the coding tool whose maker SpaceX had agreed to buy for $60 billion three weeks earlier. Cursor's own launch post says Grok 4.5 is a mixture-of-experts model it "trained jointly with SpaceXAI" on "trillions of tokens of Cursor data which capture a wide-range of user interactions with codebases and software tools." [1][2][4]
Atlas interpretation: By July 2026, SpaceX had acquired the model maker and the coding tool it now trains alongside inside a five month span, and Grok 4.5's launch was the first release to arrive after both deals had been struck, though the Cursor purchase would not close until August. The model's specific strength on software engineering benchmarks and its availability inside Cursor from day one reads less like a coincidence of timing and more like the point of buying both companies. [5][4]
Sources
- Introducing Grok 4.5
xAI · Jul 16, 2026
- Introducing Grok 4.5
Cursor · Jul 8, 2026
- SpaceXAI launches Grok 4.5, touts lower coding-task costs than AI rivals
InfoWorld · Jul 9, 2026
- SpaceXAI's newest AI model Grok 4.5 dramatically undercuts Anthropic and OpenAI on price
SiliconANGLE · Jul 8, 2026
- xAI Rebrands as SpaceXAI, Launches New Grok 4.5 Model
The Epoch Times · Jul 12, 2026