SpaceX's biggest customer isn't the US government, but Anthropic, the company behind Claude. A rocket company that derives a third of its revenue from renting out data centers. A major client, listed only as "Customer B" in SpaceX's filings last week, contributed approximately 34.5% of its third-quarter revenue. Rumors are now circulating that Customer B is Anthropic. Neither company has confirmed this. Anthropic isn't buying rocket launches; it's buying computing power. Earlier this year, it signed an agreement with SpaceX to use computing resources at SpaceX's Memphis, Tennessee data center. That's how it generated that third-quarter revenue. And this is just the beginning. According to Anthropic's IPO filings, it will pay SpaceX up to $120.5 billion by 2029, averaging about $3.1 billion per month starting this December. However, this money isn't locked in. The contract sets out exit points in January and March 2027. After these dates, Anthropic can terminate the lease with 90 days' notice. The US government, a long-time client, is now paying less than the rent a single AI company has paid.