Legion LegalTech says the export directive that shut down Fable 5 and Mythos 5 worldwide has done “immediate, irreparable, and existential” harm to its business.

US legal-technology company has sued the federal government over the directive that, two weeks ago, forced Anthropic to switch off its two most capable AI models for everyone on Earth.

Legion LegalTech Corp filed its complaint on Tuesday in federal court in Washington, DC, asking a judge to vacate the order and signalling that it will seek an injunction to stop the administration from enforcing it.

The order at the heart of the case came from the Commerce Department’s Bureau of Industry and Security on June 12.

Citing national security, it required Anthropic to disable Fable 5 and Mythos 5 for “any foreign national,” inside or outside the United States, including the company’s own foreign-national staff.

Because Anthropic could not reliably check nationality in real time, the only way to comply was to turn both models off for every customer the same day. The company has called the action disproportionate.

Legion is the unlikely plaintiff the order seems almost calculated to produce. The San Jose company builds drafting and case-management tools for attorneys and depends on Anthropic’s models for its platform.

It is American, but its software-development team includes Canadian nationals who work from Canada, exactly the category the directive targets. When access vanished, so did the team’s ability to do its job.

The language in the filing is not that of a routine procurement dispute. “The harm to Legion is immediate, irreparable, and existential,” the complaint says.

“The pace of frontier AI advancement is blistering, and competitive ground lost during a suspension cannot be regained after the fact.”

The company is asking the court to set aside the directive and says it will seek a preliminary order barring enforcement while the case proceeds.

Anthropic is not a party to the lawsuit. Asked to comment, it pointed to a prior statement saying it was “grateful to the administration for their ongoing partnership in working to get this matter resolved as quickly as possible.”

The Commerce Department and the White House did not immediately comment.

The government has not spelled out its concern in public. Its understanding, by Anthropic’s account, is that someone found a way to bypass, or “jailbreak,” Fable 5.

Anthropic says it has seen only a narrow technique that amounts to asking the model to read a codebase and fix its flaws, and that the vulnerabilities surfaced were minor and already publicly known.

The episode is notable because it is the first time Washington has used export controls to pull a commercial AI product, rather than hardware, off the market.

What makes the Legion suit sharper than a single customer’s grievance is the legal posture it joins.

Anthropic and the US are already locked in litigation in Washington and California after the company sued over the Pentagon’s move to brand it a national security supply-chain risk, which followed Anthropic’s refusal to let the military use Claude for autonomous weapons or domestic surveillance.

The administration that restricted the models is the same one that has urged banks to adopt the technology and, before that, opposed expanding civilian access to Mythos even as the NSA kept using it.

The collateral damage reached beyond US borders. The directive cut off allied users, including the UK’s AI Security Institute, one of the leading bodies for testing frontier models, which had been actively evaluating the systems it lost access to.

That is part of why the case is being watched outside the courtroom: it tests whether a security order aimed at foreign nationals can be squared with a model deployed to hundreds of millions of people, many of them paying customers with no plausible link to the concern.

For now, the questions are procedural. Legion wants the directive vacated and, in the meantime, frozen. The government has yet to respond. And the models remain offline, which means the clock the company calls existential is still running while the lawyers argue.