OpenAI ends Cursor deal: Is Elon Musk responsible for Sam Altman's company cutting off AI models? What we know

OpenAI said on Friday that it intends to stop supplying AI models to Cursor, a coding-tool company now owned by Elon Musk’s SpaceX. The move marks another escalation in the long-running rivalry between OpenAI CEO Sam Altman and Musk.

OpenAI stated it was taking the decision because it could not be certain that SpaceX would use its technology in accordance with its terms of service. The company cited its past experience with Elon Musk’s businesses allegedly violating contractual agreements.

The dispute between Musk and Altman has persisted for years and intensified earlier this year during a trial stemming from Musk’s $150 billion lawsuit against OpenAI. During the proceedings, Musk’s lawyer said Musk and other witnesses had testified that Altman was a liar. OpenAI, meanwhile, claimed that Musk had sought to gain control of the company.

"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 mentioned in a blog post.

Musk responds

Musk responded early Saturday in a post on X, saying, "I couldn't care less."

He called Altman and OpenAI President Greg Brockman "untrustworthy" and reiterated his claim that they “stole an open source nonprofit”.

Musk, the world’s richest person, had sued OpenAI and Altman, accusing them of "stealing a charity" by abandoning the company’s original nonprofit mission in pursuit of personal financial gains. A federal jury ruled against Musk earlier this year, concluding that he had brought the lawsuit too late.

‘We typically rely on custom contracts to ensure compliance’

In its blog post, OpenAI said X, the platform formerly known as Twitter and now owned by SpaceX, had violated the terms of its agreement with OpenAI after Musk acquired the social media company.

The AI firm said that when working with major partners such as SpaceX, it generally uses customised contracts to ensure compliance with its terms of service and maintain safety at scale.

"To work with a large partner like SpaceX, we typically rely on custom contracts to ensure compliance with our terms of service and that the integration provides for safety at scale," it mentioned.

OpenAI, the company behind ChatGPT, said it had proposed November 12, 2026, as the date for cutting off access. It added that its agreement with Cursor provided only a limited period to terminate the contract following “a change of control.”

Hours after OpenAI announced its decision, Anthropic, which competes with both companies but has an existing partnership with SpaceX, said it would increase computing capacity to support its Claude models on Cursor, according to company co-founder Tom Brown.

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

Meanwhile, Michael Truell, a Cursor co-founder who is now an executive at SpaceX, said on X that the company was in discussions with OpenAI’s team to find a resolution to the issue.