Details of the transaction emerged from SpaceX’s S-1 filing with the SEC. The deal, the company said, “allows us to monetize unused compute capacity in our infrastructure.” The terms of the deal allow either side to terminate the contract with 90 days’ notice.

“We expect to enter into additional similar services contracts,” the filing stated.

The move has given xAI a hybrid stance in the AI market. Most players either build data centers for themselves or build data centers for others to use — rarely both simultaneously. This emerging model, sometimes called a “neocloud,” lets AI companies offset infrastructure costs by acting as a cloud provider when their own usage falls short of capacity.

SpaceX argues the arrangement is a savvy use of resources. “We believe our dual monetization strategy provides multiple pathways to generate returns on invested capital,” it wrote. But the subtext is hard to miss: xAI appears to have overbuilt its compute capacity and needed to find a way to monetize it ahead of a public offering. Usage of Grok — xAI’s flagship AI assistant — has dropped significantly in recent months, freeing up servers that the company is now selling to one of its closest competitors.