How long is Anthropic’s lease with SpaceX? Opinions vary.

Earlier this month, xAI signed a major compute deal with Anthropic, pledging billions of dollars a month for exclusive use of the company’s Colossus cluster. It was a coup for both companies, giving xAI some much-needed revenue and helping Anthropic catch up in the never-ending race for compute.

But this morning on X, Elon Musk downplayed exactly how much SpaceX had committed to the deal.

“SpaceX has not committed to leasing Colossus for years, although it’s possible that may be what happens,” he said, replying to a user. “This is a 180 day lease with 90 day notice mutual cancellation thereafter. The short term was our request, not Anthropic’s. We won’t leave them hanging and will provide a reasonable off-ramp, but if compute gets super tight I said we might need it back at some point.”

Musk’s statement directly contradicts SpaceX’s recent S-1 filing, which confirms the standard 90-day cancellation but presents the deal as a three-year agreement. Page F-62 of the filing reads:

On May 3, 2026, the Company entered into a cloud services agreement with Anthropic PBC, an AI research and development public benefit corporation, with respect to access to compute capacity. Pursuant to this agreement, the customer has agreed to pay a monthly fee through May 2029, with capacity ramping in May 2026 at a reduced fee. The agreement may be terminated by either party upon 90 days’ notice. The customer will retain ownership and intellectual property rights in its content, AI models, and related data.

The key point here is that Anthropic “has agreed to pay a monthly fee through May 2029” — a pretty straightforward description of a three-year lease. The same language is repeated on F-96 and in slightly varied form (“the customer has agreed to pay us $1.25 billion per month through May 2029”) on pages 13 and 146, so it’s not as if there was a typo.

xAI did not respond to a request for clarification.

Maybe we can quibble about whether Anthropic agreeing to pay for a service means the same thing as SpaceX agreeing to provide that service, but that’s not usually what “lease” means. And why have a one-way lock-in if either party can terminate the deal with three months’ notice anyway?

I don’t have the deal in front of me, so I don’t know what it says — and neither SpaceX nor Anthropic is saying anything about the duration of the deal in their announcements. Still, there should be a pretty straightforward fact of the matter here, and it’s not the sort of thing you want to make false statements about during a company’s quiet period.

As always, we should note that the SEC probably will not do anything — and even if they did, Elon probably wouldn’t care. But this sort of does seem like a material misrepresentation made while marketing a security, which is bad karma at the very least.

Sean O’Kane contributed reporting to this article.