Anthropic is struggling to obtain sufficient cloud capacity from AWS, Google, and Microsoft, as these providers increasingly view the Claude developer as a rival rather than a client, according to an S-1 filing obtained by The Wall Street Journal. The leaked document adds detail to figures previously reported by Reuters and the Financial Times in late September, including Anthropic's estimate that it could spend more than $750 billion on cloud contracts—some of which remain under negotiation. Even at that scale, the capacity still falls short.

Anthropic is leasing its own data centers and partnering with third-party data center operators. However, the company is concerned that these operators have a "limited operating history," potentially making them less dependable than the major hyperscalers. This massive spending follows an $80.7 billion net loss in the first half of the year. During the same period, the company reported $16.3 billion in revenue, with just two customers accounting for roughly one-fifth of sales, according to the WSJ report.

Expanding on previously disclosed catastrophic risk warnings, the filing also cautions that Anthropic could face liability for damages resulting from harmful AI behavior at a level exceeding its available insurance coverage. Last week, the company informed prospective investors that third-quarter revenue alone has now hit $16.8 billion, a 45% increase from the prior quarter. Anthropic is reportedly aiming for a November IPO.