OpenAI announced in a late-night blog post on Friday, September 2026, that it is ending its partnership with Cursor, one of its most valuable customers, following SpaceX’s $60 billion acquisition of the AI coding startup. The decision will cost OpenAI an estimated $1 billion or more in annualized revenue.
Cursor, the company behind a widely used AI coding editor, had been among OpenAI’s top five customers by revenue at the start of 2026. By spring of that year, OpenAI internally estimated the partnership would generate more than $1 billion in annualized revenue, according to people familiar with the matter who spoke to WIRED.
OpenAI cited distrust of Elon Musk as the reason for the split. “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,” the company wrote in its blog post. OpenAI also noted that Musk appeared to acknowledge during a deposition in his lawsuit against the company that xAI — now part of SpaceX — used OpenAI’s models to train its own. A federal jury dismissed that lawsuit earlier this year.
Cursor founder and CEO Michael Truell, who now leads teams at SpaceX, responded on X, claiming OpenAI’s models account for only about 5% of Cursor user traffic. OpenAI’s head of core products, Thibault Sottiaux, pushed back, stating that token usage is “not a proxy for revenue nor value created” and asked Truell to “share the math.”
The breakup comes as OpenAI prepares for a public offering and works to reduce dependence on any single partner or revenue stream. The company reportedly now generates more than $40 billion in annualized revenue across subscriptions, advertising in ChatGPT, and its own AI coding tool, Codex — which directly competes with Cursor.
OpenAI acknowledged in its blog post that ending the partnership may damage its standing with the developer community, which has long used Cursor as a key channel to access its models.
Source: WIRED