SAN FRANCISCO, CALIFORNIA — U.S. District Judge Rita Lin blocked enforcement of the government's supply chain risk designation against Anthropic and halted President Donald Trump's order requiring all federal agencies to immediately cease using Anthropic's technology.

"At bottom, Anthropic has shown that these broad punitive measures were likely unlawful and that it is suffering irreparable harm from them," Lin wrote in court filings. "Punishing Anthropic for bringing public scrutiny to the government's contracting position is classic illegal First Amendment retaliation," she wrote.

Lin stayed her order for seven days, allowing the government an opportunity to appeal.

Anthropic sued the federal government earlier this month. In its lawsuit, Anthropic alleged that the government's actions were an unprecedented and unlawful attempt to punish the company for exercising First Amendment rights.

The government's supply chain risk designation aimed to prevent private government contractors from using Anthropic's Claude AI model. Trump's order required all federal agencies to immediately cease using Anthropic's technology, with a six-month phase-out period for the military.

Lin wrote that the government did not demonstrate why Anthropic posed a supply chain risk and did not follow required legal processes for that designation. She wrote that Anthropic's due process rights were likely violated because the company did not have an opportunity to respond to the government's actions.

Defense Secretary Pete Hegseth described Anthropic as sanctimonious and said the company delivered a master class in arrogance.

Federal agencies other than the Pentagon quickly terminated their use of Claude following the administration's actions against Anthropic. Justice Department attorney Eric Hamilton stated that a supply chain risk designation would only prevent government contractors from using Anthropic's technology for military-related work, not their other business.

Pentagon Chief Technology Officer Emil Michael exchanged cordial contract negotiation emails with Anthropic CEO Dario Amodei while the military referred to Anthropic as a serious threat.

Lawyers for Anthropic and the federal government appeared in person at a hearing in San Francisco federal court.