Elon Musk’s xAI Sues Chinese Engineer, Who Joined Competitor OpenAI, for Theft

xAI has filed a lawsuit against a former engineer, accusing him of “willfully and maliciously” stealing xAI documents and seeking an emergency restraining order to prevent him from joining rival company OpenAI.
Published: 9/1/2025, 11:14:27 PM EDT

xAI has filed a lawsuit against a former engineer, accusing him of “willfully and maliciously” stealing xAI documents and seeking an emergency restraining order to prevent him from joining rival company OpenAI.

In a federal lawsuit filed on Thursday in the Northern District Court of California, xAI alleged that ex-employee Li Xuechen stole proprietary information of xAI’s advanced business model and trade secrets prior to leaving the company to work for competitor OpenAI.

xAI accuses Li of breach of contract, theft of trade secrets, fraud, and violation of California’s computer fraud statute, and seeks an emergency restraining order to prevent Li from working at OpenAI until the trade secrets issue is resolved.

Elon Musk, the owner of xAI and Tesla, said that Li didn’t just take a few files but uploaded xAI’s entire codebase. He posted on X, “He accepted an offer at OpenAI and then uploaded our entire codebase!”
Li, a Chinese national and a Stanford graduate in computer science who holds permanent residency in Canada, joined xAI in 2024 as one of its first 20 employees. He had access to xAI’s most sensitive data, including proprietary model architectures, advanced optimization algorithms, and the entire Grok codebase, court documents say.

Grok is xAI’s advanced large language model that competes with other models like OpenAI’s ChatGPT and Google’s Gemini.

In June 2025, Li sold $4.7 million in xAI shares, followed by an additional sale of $2 million in July, according to the lawsuit. It accuses Li of “willfully and maliciously” copying documents from his xAI-issued laptop onto at least one personal system on the same day his $6.7 million in cash from the sale became available.

At the same time, xAI said that Li took extensive measures to hide his actions, such as deleting browser history and system logs, renaming files, and compressing them before transferring them to his personal devices, it alleged.

On July 28, Li resigned from xAI, signing a termination certification stating he had complied with confidentiality agreements and returned or deleted all company data, xAI said.

However, xAI’s security team detected irregularities during a routine check, prompting an immediate internal investigation that pointed to Li, who was set to start at OpenAI on Aug. 19.

xAI and Li held two intense meetings with lawyers present. During one meeting, Li confessed to taking company documents and concealing his actions, documenting his "negligence" in a handwritten statement.

The lawsuit highlights the intense race for top AI talents. Musk, also a co-founder of OpenAI, has previously sued OpenAI and its CEO, Sam Altman, saying they had strayed from their mission to benefit humanity after the company shifted from its original non-profit public mission to a for-profit model with Microsoft as its main backer. OpenAI filed a countersuit in April, accusing Musk of harassment.
xAI also filed another lawsuit on Aug. 25 in Texas against OpenAI and Apple, accusing them of monopolistic practices in the AI chatbot market on Apple devices.