Anthropic is SpaceX’s largest single customer, a person familiar with the matter said, accounting for more than a third of the revenue for Elon Musk’s artificial intelligence, satellite and rocket venture during the third quarter of this year.

SpaceX said in a filing last week that about 34.5% of its revenue during the last quarter came from a single client paying its AI division, now called Super Intelligence, which supplies computing power. That client, only identified as “Customer B” in the filing, is Anthropic, said the person, who declined to be identified as the details are private.

Revenue from Anthropic has surpassed payments from the U.S. federal government, previously SpaceX’s biggest single customer, and underscores the exposure to a client with the contractual ability to exit the deal as soon as next year.