Anthropic's Claude Mythos and Fable models are so far ahead of competitors that even the man providing their computing infrastructure admits it.
Elon Musk declared the AI startup the industry leader Thursday, saying on X that he was "clearly wrong about Anthropic" after spending the past year calling the company "hypocritical," "woke," and predicting its "fate is to be misanthropic."
"No company has released a model as good as Mythos/Fable and they will undoubtedly have Mythos 2 ready soon," Musk wrote. The admission carries unusual weight because SpaceXAI competes directly with Anthropic through its Grok models while simultaneously serving as Anthropic's largest computing partner.
In May, Anthropic signed a deal to lease capacity from SpaceX's Colossus 1 data center, agreeing to pay $1.25 billion per month through May 2029 in a contract worth roughly $40 billion in revenue for SpaceXAI's xAI unit. The Colossus system houses more than 220,000 Nvidia GPUs with approximately 300 megawatts of computing capacity.
Musk's praise arrived one day after SpaceXAI launched Grok 4.5, the company's first model since going public and acquiring AI coding startup Cursor. Independent analysis from Artificial Analysis ranks Grok 4.5 as the top non-Anthropic model, with two Anthropic models, Fable 5 and Opus 4.8, still occupying higher spots.
The X post was triggered by a user questioning whether Anthropic was taking a risk by relying on SpaceX infrastructure given the competitive dynamic. Musk rejected the notion entirely.
"I would never cut them off in a way that hurt them badly, even as a competitor. That's not my style," he wrote.
He pointed to Tesla's open-source patents and its Supercharger network opened to competitors as precedent. The warmer posture toward Anthropic began in May, the same day the computing deal was announced. Musk said he spent time with senior Anthropic team members and was impressed by their approach to safety.
"So long as they engage in critical self-examination, Claude will probably be good," he wrote then. But the billionaire hasn't fully abandoned the competitive edge. "Space(XAI) is only 3 years old.
That's half the age of Anthropic and quarter the age of OpenAI," he posted on May 26. "Let's see where things stand 3 years from now."
Either side can terminate the computing agreement with 90 days' notice, according to SpaceX's S-1 filing.
