Elon Musk's frontier generative AI startup xAI formally opened developer access to its Grok 4.1 Fast models last night and introduced a new Agent Tools API—but the technical milestones were ...

Update: A day after this article was published, xAI unveiled Grok 4.1 access through its API for $0.20 per 1 input million tokens (or $0.05 for cached input) and output tokens at $0.50 per million, ...