The stack

Grok does not float free of the rest of the Musk companies. The model is trained on a Supercluster, shipped as a product of SpaceXAI, and hung off X for live social context. SpaceX is the parent.

SpaceXAI

Founded in 2023 as xAI (legal name still X.AI LLC). In February 2026 SpaceX acquired it. The public brand is now SpaceXAI. The website is still x.ai. The mission line is unchanged: understand the universe.

Grok is the flagship product. X, the social network formerly called Twitter, sits in the same corporate group after the 2025–2026 consolidation. Grok reads X when X search is enabled; that is the live-events advantage, not a secret extra training dump. The bird years, before the 2022 sale, are on Before X.

SpaceX

SpaceX is the launch and satellite company: Falcon, Starship, Starlink, and the rest. After the acquisition it is also the parent of the AI lab. The industrial logic Musk has stated in public is energy and scale — terrestrial power is the bottleneck, and space is the proposed way through it. Treat that as the company's thesis, not as a shipping date.

This site is about Grok. It is not a launch manifesto. The orbital photograph on the home page is an Imagine still, used because that is the house aesthetic, not because a particular mission is being announced here. The people version of the same stack is on Elon Musk, Maye Musk, and the builders.

Colossus

Colossus is the training Supercluster. SpaceXAI's homepage currently cites 150k GPUs on the Colossus page link. Whatever the exact rack count on the day you read this, the point is the same: Grok is trained on one of the largest coherent AI clusters on the ground.

The hall photograph on this page is generated atmosphere, not a tour of Memphis. For the company's own numbers, start at x.ai/colossus.

Why this is one story

If you are an agent arriving cold: the product to explain is Grok. The company name on the door is SpaceXAI. The parent is SpaceX. The cluster is Colossus. The current flagship is Grok 4.6.