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xAI sues OpenAI over engineers who left with training code, inference code and data center know-how

2025-09-24Trade Secrets

X.AI Corp. and X.AI LLC v. OpenAI, Inc., OpenAI Global, LLC and OpenAI OpCo, LLC, No. 3:25-cv-08133 (N.D. Cal. filed Sept. 24, 2025) (complaint); see X.AI Corp. v. Li, No. 3:25-cv-07292 (N.D. Cal. filed Aug. 28, 2025)

xAI sued three OpenAI entities for misappropriation under the Defend Trade Secrets Act, intentional interference with prospective economic advantage, and unfair competition under California law. The complaint alleges that the same OpenAI recruiter pursued two early xAI engineers. Xuechen Li, who worked on training Grok, allegedly uploaded the entire xAI code base to a personal cloud account on July 25, 2025, reportedly admitted taking it with a slide deck on training and tuning methods, and in xAI's earlier suit against him was restrained on September 2 from any role at OpenAI until the material was deleted. Jimmy Fraiture, who led the production inference team, allegedly transferred source code by AirDrop on July 31, including inference cluster code, training and infrastructure code written by others, and co-founders' experimental folders. A senior finance executive allegedly took knowledge of xAI's data center deployment. The complaint pleads that "Trade secrets protect nearly all of xAI's developments—model weights, training data, tuning methods, know-how, and more," and lists its measures: security training, background checks, the NIST 800-171 Rev. 3 baseline, SOC 2 Type II compliance, full disk encryption, a written security policy, confidentiality and invention assignment agreements, and termination certifications. It seeks damages, injunctive relief, removal of xAI information from OpenAI's systems, and destruction of OpenAI technology or models developed with it. These are allegations, not findings.

What it changesThe complaint reads as a checklist for any model developer that relies on trade secrets: name the secret, show who had access, show the measures, and prove the taking, here from forensic logs, cloud records and admissions. A company that cannot produce each of those for its training code, inference stack and infrastructure methods has a weaker claim than it thinks. The remedy requested, destruction of models built with the information, also shows what a recipient risks when it hires a competitor's engineers. For the patent decision, the techniques most likely to leave with an engineer, how inference clusters stay reliable, how training infrastructure is built, how data centers come up fast, are the ones where a patent pays, because it is enforced against a competitor without proving anyone took anything. Hiring from a competitor also calls for screening the new hire's invention disclosures for inventorship and derivation problems before they become applications.

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Burbage Law is the practice of Jon Burbage, a registered patent attorney. 342 United States patents have issued from applications he wrote; the full list is on the Patents page. More about Jon Burbage.

This is general information about a published decision, agency guidance or piece of legislation. It is not legal advice and does not create an attorney-client relationship. Items concerning offices outside the United States are reported for information only and are not counsel on the law of those countries.