OpenAI said on Friday that it plans to stop providing its AI models to Cursor, the coding-tool company owned by Elon Musk’s SpaceX, escalating the growing rivalry between OpenAI CEO Sam Altman and Musk.

SpaceX announced in June that it had agreed to acquire Anysphere, the startup behind Cursor, for $60 billion in an all-stock deal. The acquisition was completed earlier this month.

“We are making this choice because we cannot be confident that SpaceX will use our technology within our terms of service, based on our experience with Elon Musk’s companies violating contracts,” OpenAI said in a blog post.

The co-founder of Cursor and now an executive at SpaceX, Michael Truell, said the company was in discussions with OpenAI to resolve the issue.

“Cursor was one of the very first users of OpenAI, we’ve worked closely with their team for years, and we’ve trusted their platform to be neutral infrastructure for our business,” Truell said in an X post on Friday.

Musk and Altman have been embroiled in a bitter feud for years, with their dispute eventually escalating into a court trial.

During the proceedings, Musk’s lawyer said Musk and other witnesses had testified that Altman was a liar, while OpenAI argued that Musk had sought to gain control of the company.

Musk, the world’s richest person, filed a $150 billion lawsuit against OpenAI, accusing the company and its CEO, Sam Altman, of betraying its original nonprofit mission in pursuit of personal financial gain.

A federal jury ruled against Musk earlier this year, determining that he had waited too long to bring the case.

In a blog post, OpenAI also accused X, formerly known as Twitter and now owned by SpaceX, of violating the terms of its contract with OpenAI following Musk’s acquisition of the social media platform.