OpenAI is winding down its partnership with Cursor after SpaceX acquired the AI coding startup, according to WIRED, cutting off a customer the company had recently estimated could generate more than $1 billion in annualized revenue. WIRED reports that OpenAI announced the move in a late-night blog post last Friday. OpenAI’s stated reason, as quoted by WIRED, was that it could not be confident SpaceX would use OpenAI technology within its terms of service, citing the company’s experience with Elon Musk’s companies “violating contracts.” OpenAI declined to comment to WIRED, and representatives for SpaceX and Cursor did not immediately respond to WIRED’s requests for comment. The reported economics make the decision notable. Cursor has paid OpenAI to make the ChatGPT maker’s models available inside its AI coding editor, according to WIRED. People familiar with the matter told the outlet that Cursor was one of OpenAI’s top five customers by revenue at the start of 2026. By spring, OpenAI had estimated that the partnership would bring in more than $1 billion in annualized revenue, based on its performance at that time, WIRED reports. SpaceX recently acquired Cursor in a $60 billion deal, according to WIRED. Cursor founder and CEO Michael Truell, who WIRED says is now leading teams at SpaceX, responded publicly to OpenAI’s announcement on X by saying OpenAI’s models serve about 5% of Cursor user traffic. Thibault Sottiaux, OpenAI’s head of core products, replied that token usage is not a proxy for revenue or value created and asked Truell to share the math behind the figure, WIRED reports. The breakup also lands in a competitive overlap. WIRED says Cursor leaders had hoped to remain a platform for third-party AI models from OpenAI and Anthropic after the SpaceX acquisition. At the same time, OpenAI has been building Codex into a larger AI coding business, putting it increasingly in competition with Cursor for customers. WIRED reports that OpenAI is trying to show investors a more stable business as it prepares to go public next year. The outlet notes that OpenAI reportedly now generates more than $40 billion in annualized revenue across several lines of business, including subscriptions, ads in ChatGPT, and access to Codex. That broader revenue base may make the loss of a large Cursor relationship easier to absorb than it once would have been, but the reported size of the account shows that OpenAI was willing to give up a material customer relationship. The developer impact is less settled. WIRED reports that OpenAI acknowledged ending the partnership could hurt its standing with developers by removing a major channel through which they accessed OpenAI models. Cursor, meanwhile, publicly suggested OpenAI accounted for a small share of user traffic. Those two claims are not necessarily inconsistent, but they point to the central open question: whether the value of OpenAI’s Cursor relationship was concentrated in high-value usage rather than broad traffic share. Who benefits: OpenAI’s stated rationale is that ending the Cursor relationship avoids a use of its technology by SpaceX that it said it could not be confident would stay within its terms of service. Who's exposed: Developers who used Cursor as a channel to access OpenAI models may be affected by the wind-down. OpenAI is also exposed to developer backlash, which WIRED says the company acknowledged as a possible consequence.