Musk walks back the Anthropic Colossus deal to a six-month lease

SpaceX did not commit to a multi-year lease of its Memphis Colossus 1 cluster to Anthropic, Elon Musk said on Wednesday, describing the agreement as 180 days with a 90-day mutual cancellation right.

Elon Musk has clarified that SpaceX did not commit to a multi-year lease of its Colossus 1 data centre to Anthropic, contradicting widely reported framing of the deal as a $1.25bn-per-month, three-year arrangement running through May 2029.

The agreement, Musk said in posts on his X account on Wednesday, is in fact a 180-day base lease with a mutual 90-day cancellation right on either side after that.

“The short term was our request, not Anthropic’s,” Musk wrote. “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.”

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The clarification matters because it lands inside the SpaceX IPO roadshow window. The company filed for its public listing last week.

The S-1 mentions a 90-day mutual cancellation provision on the Anthropic agreement but does not, as initially reported, anchor the deal at the six-month base term Musk has now publicly named.

The disclosure gap, combined with the visible revision of the deal duration in public Musk statements, will be one of the questions analysts and prospective LPs press on during the roadshow that starts in earnest in June.

The underlying transaction is itself worth recapping. Anthropic announced earlier this month that it had taken access to the full compute capacity of Colossus 1, the Memphis facility built originally to train xAI’s Grok. Colossus 1 houses more than 220,000 Nvidia GPUs and provides over 300 megawatts of compute capacity.

The published monthly rent figure was $1.25bn. Anthropic immediately used the new compute headroom to raise rate limits on Claude Code and Opus API customers, citing the SpaceX deal specifically.

xAI had by then moved its own model training to Colossus 2, a newer and larger facility, leaving Colossus 1 available for external lease.

What changed today is the lease-term reading. A 180-day base term with 90-day post-base cancellation is a meaningfully different commercial commitment from a 36-month contract.

For SpaceX, the short term retains flexibility to reclaim compute if Grok training demand or other internal SpaceX-xAI requirements spike.

For Anthropic, it means the Colossus capacity is a useful near-term bridge rather than the structural data-centre anchor analysts had read it as.

Anthropic’s public posture around the deal, particularly the Claude rate-limit increases announced earlier this month, presumed a longer-term arrangement than Musk has now confirmed.

The IPO-disclosure question is the part SEC lawyers will care about. SpaceX is a private company filing for a public listing. Material commercial agreements with revenue impact are required disclosure.

A 36-month deal worth $45bn cumulative ($1.25bn × 36) is structurally different from a 6-month deal with mutual cancellation worth at most $7.5bn ($1.25bn × 6) if no extension is negotiated.

The S-1’s mention of the 90-day cancellation provision but not the 180-day base term sits in the gap between the two readings.

The Musk-Anthropic relationship is itself the contextual oddity. Musk has spent the past two years publicly describing Anthropic as “Misanthropic” and as a competitor to xAI.

All 11 xAI co-founders have departed over the past year, and xAI itself lost $6.4bn from operations on $3.2bn of revenue in 2025, with growth well below the rates Anthropic and OpenAI have posted.

The Colossus 1 rental to Anthropic was already commercially logical given xAI’s capacity utilisation and SpaceX’s IPO timing. Today’s revision suggests Musk now wants the flexibility to walk it back if circumstances change.

Neither SpaceX nor Anthropic separately commented on the lease-term clarification through formal channels. The SpaceX IPO roadshow is scheduled to begin on 8 June.