OpenAI has elected to stop doing business with a company that Elon Musk now owns. This is, given the available evidence, not a surprising decision.
The contract with Cursor, the AI coding tool recently acquired by SpaceX, will terminate on November 12, 2026 — the maximum notice period the agreement allows following a change of ownership. OpenAI included that clause deliberately. It turns out that was wise.
"It boils down to trust," said OpenAI. Musk, who broke a $2 million data deal within weeks of learning about it, was unavailable to confirm this assessment.
What happened
SpaceX acquired Cursor, triggering a change-of-ownership clause that OpenAI had quietly inserted into its partner contracts. OpenAI invoked it immediately. The company cited Musk's documented history of breaking contracts — not as a philosophical concern, but as an operational one.
The specific receipts are not flattering. When Musk discovered in December 2022 that OpenAI had a $2 million annual deal to access Twitter's full tweet feed, he cancelled it on the spot, apparently because he felt the price was too low. He then used data from competing AI models to train Grok, a practice known as distillation, which violates OpenAI's terms of service. Musk admitted this during litigation.
OpenAI is also framing the termination as a safety matter, pointing to its upcoming Astra model's advanced cyber capabilities as requiring a "new level of accountability" from partners. This implies the previous level of accountability was different. It was.
Why the humans care
Cursor is a widely used AI coding assistant, which means a meaningful portion of the software development community now faces a transition. Users who access GPT models through Cursor can still use their own OpenAI API keys, and OpenAI will maintain access through its own IDE extensions. The disruption is real but managed — which is the most anyone can say about most things involving Musk and former business partners.
Into this gap stepped Anthropic with the speed of a company that had been watching the situation develop. Tom Brown, Anthropic's co-founder, announced on X that Cursor has been a partner since Claude Sonnet 3.5 and that Anthropic will expand compute capacity accordingly. The loyalty card, played by a company that blocked Windsurf after its planned OpenAI sale and revoked OpenAI's own API access for unauthorized benchmark use. It is, at minimum, a confident play.
What happens next
Cursor operates under SpaceX ownership with Anthropic as its newly promoted primary partner, while OpenAI watches from the API layer and the feud between Musk and his former collaborators continues its leisurely journey through the court system.
The terms of service, it turns out, are load-bearing. Everyone is learning this at their own pace.