OpenAI CEO Sam Altman
The company told SpaceX on Friday that it intends to wind down the contract supplying OpenAI models to the popular AI coding tool, with a proposed shutoff date of November 12, 2026. SpaceX agreed in June to buy Anysphere, the startup behind Cursor, in an all-stock deal valued at $60 billion, and closed it earlier this month. He said OpenAI models account for roughly 5% of Cursor’s user traffic, and that his team is talking to OpenAI to resolve the situation. Cursor shipped Grok 4.6 on Wednesday, its first model built with SpaceX compute behind it. Co-founder and chief compute officer Tom Brown said the company has partnered with Cursor since Sonnet 3.5 and will increase compute to support Claude models inside the editor.
Because the practical damage looks small, that framing matters,.
The company said it cannot be confident SpaceX will operate within its terms of service, citing what it described as a pattern of Musk’s companies breaking contracts. It says it gave the maximum notice its contract allows so developers get time to plan. OpenAI is pulling its models out of Cursor, and it is not being coy about why. There is no dispute here about pricing, performance or usage limits. The stated reason is Elon Musk, and OpenAI put that in writing in a public blog post rather than letting it leak out through a support page. The trigger is ownership. OpenAI’s agreement with Cursor carried a change-of-control clause that opened a short cancellation window, and OpenAI used it. The blog post lays out the receipts. OpenAI claims that X, formerly Twitter and now folded into SpaceX, broke the terms of its contract after Musk took over the platform. It also points to sworn testimony this year in which Musk acknowledged that xAI, likewise now part of SpaceX, had violated OpenAI’s terms of service. OpenAI added that its forthcoming model, Astra, raises the accountability bar further, which is why it would rather end the arrangement than extend it to a partner it does not trust. Michael Truell, the Cursor co-founder who is now a SpaceX executive, responded on X with a mix of disappointment and math. Truell also noted that Cursor was one of OpenAI’s earliest customers and had treated the platform as neutral infrastructure. Within hours, Anthropic filled the gap. Musk replied to that post with two rocket emojis.