OpenAI is winding down the contract that puts its models inside Cursor. The proposed shutoff is Nov. 12, 2026, after SpaceX closed a $60 billion all-stock acquisition of Anysphere, the startup behind the coding tool, on Aug. 14.
“Today, we notified SpaceX that we intend to wind down our contract providing OpenAI models to Cursor,” OpenAI wrote Friday. It said Nov. 12 is the maximum notice the contract allows, and that the decision was “incredibly tough” because it wants developers to keep using its models.
The reason is ownership, not the product. “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 that after Musk acquired Twitter, now part of SpaceX, the company broke OpenAI’s contract. It also said Musk admitted under oath this year that xAI, now also part of SpaceX, had violated OpenAI’s terms of service. The Cursor agreement, OpenAI said, gives it a limited window to cancel after a change of control. Future models, including Astra, will not go to Cursor.
Cursor CEO Michael Truell posted that OpenAI models account for about 5% of Cursor user traffic and that the companies are speaking. “We’ve trusted their platform to be neutral infrastructure for our business,” he wrote. OpenAI has not withdrawn the notice.
Elon Musk’s reply on X: “I couldn’t care less.” He also called OpenAI’s Sam Altman and Greg Brockman “utterly untrustworthy.”
Anthropic, which already sells Claude into Cursor, went the other way. Co-founder Tom Brown said Cursor has been a partner since Sonnet 3.5 and that Anthropic “will continue to increase compute to support Claude models in Cursor.”
OpenAI said the people most affected are developers who rely on its models in Cursor, and that it is ready to support them through the transition.