Elon Musk's SpaceX—which merged with xAI earlier this year—is teaming up with Anthropic to help power Claude, creating an unusual partnership between companies that have found themselves on opposite sides of President Donald Trump's administration.

The companies announced Wednesday that Anthropic will gain access to Colossus 1, xAI's massive AI supercomputer cluster built to train and run advanced AI models. Anthropic said the agreement will give it access to more than 300 megawatts of additional compute capacity and help improve service for Claude Pro and Claude Max subscribers.

"In the next few days, we'll be ramping up Claude inference on Colossus. Grateful to be partnering with SpaceX here," Anthropic co-founder Tom Brown wrote on X. "We are going to need to move a lot of atoms in order to keep up with AI demand, and there's nobody better at quickly moving atoms (on or off planet Earth)."

In a follow-up post on X, Musk said conversations with senior Anthropic staff helped convince him the company was approaching AI development responsibly.

"Everyone I met was highly competent and cared a great deal about doing the right thing," Musk wrote. "No one set off my evil detector. So long as they engage in critical self-examination, Claude will probably be good."

Musk added that "SpaceXAI" had already moved training to Colossus 2, a much larger next-generation AI supercomputer cluster designed to surpass Colossus 1's roughly 220,000 Nvidia GPUs and support future Grok models.

The partnership comes as Musk and Anthropic CEO Dario Amodei have increasingly represented different camps inside the AI industry. Musk has aligned himself closely with Trump and the U.S. Departments of Justice and Defense. At the same time, Anthropic has positioned itself as one of the industry's strongest advocates for responsible AI safety standards.

That stance recently put the company in conflict with the Trump administration and the Pentagon after Anthropic refused demands to allow unrestricted military use of Claude. The dispute centered on safeguards blocking the model from being used for mass domestic surveillance or fully autonomous weapons. Trump later ordered federal agencies to phase out Anthropic's technology, while Pentagon officials argued military contractors must permit "any lawful use" of AI systems used by the government.

The agreement underscores how the race for computing power is reshaping alliances across Silicon Valley. In February, Elon Musk folded xAI into SpaceX, arguing that electricity demand and cooling requirements are limiting the growth of Earth-based AI data centers. Musk clarified on X on Wednesday that the xAI entity will be dissolved, and that part of the business will be known as "SpaceXAI" going forward.

Also in March, Musk accused Anthropic of being "misanthropic" after the Claude developer raised $30 billion in funding at a $380 billion post-money valuation.

Despite his previous harsh words, Anthropic said the SpaceX deal adds to a growing list of infrastructure partnerships that already includes Amazon, Google, Broadcom, Microsoft, and Nvidia.