OpenAI said Friday it plans to stop providing its artificial intelligence models to Cursor, the coding platform recently acquired by Elon Musk’s SpaceX, escalating a long-running dispute between Musk and OpenAI CEO Sam Altman.
OpenAI said it proposed November 12, 2026, as the cutoff date for its agreement with Cursor, arguing that it could no longer be confident SpaceX would use its technology in accordance with the company’s terms of service.
“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.
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The decision adds a new corporate dimension to the bitter rivalry between Musk and Altman. Their dispute dates back years and intensified after Musk sued OpenAI and Altman, alleging that the company had abandoned its original nonprofit mission in pursuit of commercial interests.
Musk dismissed OpenAI’s latest move in a post on X early Saturday, writing, “I couldn’t care less.”
He also accused Altman and OpenAI President Greg Brockman of being “untrustworthy” and repeated his claim that they had “stole[n] an open source nonprofit.”
Musk’s lawsuit, which sought to challenge OpenAI’s transition toward a for-profit structure, went to trial earlier this year. A federal jury ultimately ruled against Musk, finding that he had filed the case too late.
The dispute now threatens to affect Cursor, one of the most prominent AI-powered coding tools. Cursor is developed by Anysphere, which SpaceX agreed to acquire in June in a $60 billion all-stock transaction. SpaceX completed the acquisition earlier this month.
Michael Truell, a Cursor co-founder who is now a SpaceX executive, said on X that Cursor was already in discussions with OpenAI to resolve the dispute.
OpenAI said its agreement with Cursor contained a limited period during which it could terminate the contract following a “change of control,” giving the company grounds to seek an end to the arrangement after SpaceX took ownership.
The company also pointed to its previous experience with Musk-owned businesses. OpenAI said X, formerly Twitter, breached the terms of its contract with OpenAI following Musk’s acquisition of the social media platform.
“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,” OpenAI said.
The timing is notable because Cursor has become an important distribution channel for leading AI coding models. Cutting off OpenAI models could force the platform to rely more heavily on competing providers, potentially changing the competitive balance in AI-assisted software development.
Anthropic moved quickly to capitalize on the dispute. Hours after OpenAI announced its decision, Anthropic co-founder Tom Brown said the company planned to increase computing capacity to support Claude models in Cursor. Anthropic already has an ongoing partnership with SpaceX.
That response highlights the broader stakes for AI model providers. Coding platforms such as Cursor sit between frontier-model developers and millions of software developers, making access to those platforms strategically valuable as companies compete to establish their models as the preferred tools for programming and agentic software development.
The dispute also illustrates how ownership changes are becoming a fault line in the AI industry. OpenAI’s decision was not based on Cursor’s technology or its use of AI models itself, but on the identity of its new owner and concerns over contractual compliance.
However, the immediate issue for Cursor is whether it can maintain access to OpenAI models while continuing to operate under SpaceX ownership. For OpenAI, the decision signals a willingness to sacrifice an important distribution relationship rather than accept what it considers unacceptable contractual and safety risks.
The move is another escalation in the Musk-Altman confrontation, which has evolved from a dispute over OpenAI’s corporate structure into a broader contest involving AI models, software developers and powerful technology companies.