OpenAI to cut off Cursor after SpaceX's $60B acquisition

OpenAI will end its commercial partnership with Cursor on November 12, 2026, closing off access for a customer that had become one of its most lucrative accounts. The decision follows SpaceX's $60 billion acquisition of Cursor's parent company, Anysphere, and OpenAI's stated distrust of Elon Musk's business dealings.

The announcement came in a blog post published late Friday night, a timing that itself suggested a company trying to manage the fallout of walking away from serious money. OpenAI said plainly it could not trust SpaceX to respect its 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."

The financial stakes are significant. Cursor ranked among OpenAI's top five customers by revenue at the start of 2026, and by spring OpenAI was projecting the account would generate more than $1 billion in annualized revenue.

Cursor founder and CEO Michael Truell, who is now leading teams inside SpaceX following the acquisition, pushed back on how much OpenAI's cutoff will actually hurt his product. He said OpenAI's models handle only about 5% of the traffic running through Cursor, implying the coding tool is far less dependent on OpenAI than the revenue figures might suggest.

That gap between OpenAI's dollar exposure and its share of Cursor's actual usage is worth sitting with. It suggests OpenAI was capturing outsized revenue from a relatively small slice of Cursor's total inference workload, likely tied to premium or high-compute requests rather than everyday queries.

Why OpenAI is willing to walk away

Losing a billion-dollar account would matter far more to a smaller company than it does to OpenAI, which reportedly pulls in over $40 billion in annualized revenue from ChatGPT subscriptions, in-app advertising, and its own coding product, Codex. Sacrificing Cursor also removes a potential channel for a Musk-controlled entity to route usage into OpenAI's infrastructure on terms OpenAI does not control.

The move also reads as a proxy fight in the broader rivalry between OpenAI and Musk, who has separately pursued legal action against the company. Thibault Sottiaux, OpenAI's head of core products, oversees the unit responsible for enforcing the terms of service now cited as the reason for the split.

For Cursor, the practical impact may be limited given Truell's traffic figures, but the episode signals that OpenAI is prepared to forfeit substantial revenue to avoid doing business, even indirectly, with Musk's companies.