OpenAI has notified Cursor that it plans to end its agreement to supply AI models to the coding-tool provider after Elon Musk's SpaceX acquired its parent company. Musk responded with a fresh attack on OpenAI Chief Executive Sam Altman and President Greg Brockman, further escalating their long-running dispute.
OpenAI said on Aug. 29 that it had informed SpaceX of its intention to wind down the contract under which it provides models to Cursor. The company proposed Nov. 12 as the cutoff date, saying it represents the longest notice period allowed under the agreement.
“While this was a difficult decision because we deeply value enabling broad developer access to our models, 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.
The company's reference to past violations appears to concern xAI—now part of SpaceXAI—using OpenAI model outputs in the process of training its own AI models. Musk reportedly acknowledged aspects of that conduct while testifying in an OpenAI-related lawsuit in April.
OpenAI also cited Musk's acquisition of X, formerly Twitter, as another case in which one of his companies allegedly breached contractual terms.
Musk said in a post on X that he “couldn't care less” about OpenAI's decision. He called Altman “Scam Altman” and referred to Brockman as “Greg Stockman,” accusing the two executives of taking over an open-source nonprofit organization and calling them untrustworthy.
Musk was an early co-founder of OpenAI but later broke with Altman and Brockman. He sued the company and its executives for as much as $150 billion, alleging that they had abandoned OpenAI's nonprofit mission in pursuit of private gain. The lawsuit was dismissed after being filed beyond the applicable deadline.
OpenAI had previously tried to acquire Anysphere, Cursor's developer, but the effort did not succeed. SpaceX subsequently agreed in June to acquire Anysphere in an all-stock transaction valued at $60 billion and completed the deal on Aug. 14.
Michael Truell, Cursor's co-founder and now a SpaceX executive, said Cursor had trusted OpenAI's platform to serve as neutral infrastructure for its business.
“We're speaking with the OpenAI team to resolve this,” Truell said, adding that OpenAI models account for about 5% of Cursor's user traffic.
