OpenAI just cut off Cursor. You have until Nov 12

At 8:46 PM on a Friday, right when everyone logged off work, OpenAI posted that it is ending its partnership with Cursor, the most popular AI code editor, with a proposed shutoff date of November 12. The reason, in their own words: they cannot be confident SpaceX will use their technology within their terms of service, "based on our experience with Elon Musk's companies violating contracts." SpaceX closed its $60 billion all-stock acquisition of Cursor two weeks before.

I read the full decision on camera, then went through the tweets that actually explain what happens to people who use this thing every day, because the announcement itself is short on detail.

What OpenAI actually said

The post is short, so I read it verbatim in the video. The mechanism is a change-of-control clause: OpenAI's customer agreement with Cursor gives it a limited window to cancel after a change in ownership, and SpaceX buying Cursor opened that window. OpenAI says it is giving the maximum notice the contract allows, which is how you get November 12.

The tell is the last part: OpenAI says it decided to hold the cancellation to the latest date it can "while not providing future models to Cursor." Their upcoming model, Astra, is never coming to Cursor. Read together, this is not just winding down a contract. It is making sure the newest models never sit inside a company owned by Elon Musk, because in their view that risks the models being distilled.

My pushback, which I stand by: OpenAI and Anthropic built their models by scraping everything, research papers, libraries, books, the entire internet. Musk saying distillation is general practice is self-serving, but so is OpenAI acting like its outputs are sacred when the whole industry, Chinese open-weight labs included, trains on whatever it can reach. It is a weird finger to point. That said, the risk they are mitigating is real, and as a company answering to shareholders, I understand the move even if the beef underneath it is childish.

The receipts OpenAI is pointing at

Two things sit behind that "violating contracts" line. After Musk acquired Twitter, now part of SpaceX, OpenAI says the company broke the terms of their contract. And under oath on April 30, in the Musk v. Altman trial, Musk was asked whether xAI, also now part of SpaceX, used distillation techniques on OpenAI's models to train Grok. He called it general practice among AI companies, and when asked if that meant yes, he said "partly."

One piece of context from the research that is not in the video: Musk's $150 billion suit against OpenAI was dismissed in May as time-barred. The jury never ruled on the merits. The feud is very much alive, and Musk's reaction to the Cursor news was that he "couldn't care less."

The 5% number nobody can verify

Cursor's founder Michael Truell, whose company now sits inside SpaceX, responded that OpenAI models serve about 5% of Cursor's user traffic and that they are speaking with OpenAI to resolve it. That number did a lot of work in the coverage, and it deserved pushback.

It got some, from inside OpenAI. Tibo (Thibault Sottiaux), who leads Codex, replied that the 5% should come with strong caveats he would love Truell to share: tokens are not a proxy for revenue or value created, and OpenAI's models sit at the frontier of token efficiency, so a traffic-share measure undercounts them by construction. Smaller or less efficient models burn more tokens per task and inflate their share. He is right that it needs clarification, and none has come. Even if you are generous and call it 10 or 20 percent, that is a lot of real users caught in someone else's feud.

What still works after November 12

The most useful thing anyone posted came from Tibo as well. Two things keep working inside Cursor: your own OpenAI API key, and the Codex IDE extension running alongside it. What likely goes away is the built-in subscription routing, the thing that made the partnership convenient in the first place. With the amount of tokens serious use burns through the API, losing subscription pricing changes the math for a lot of people.

And where is Anthropic in all this? Sitting comfortably. Tom Brown, Anthropic's chief compute officer, posted that Cursor has been a trusted partner since Sonnet 3.5 and that they will keep increasing compute for Claude models in Cursor. Generous, until you remember two things people immediately pointed out under that post: Anthropic pulled Claude from Windsurf in 2025 when OpenAI was the one buying it, and Anthropic now buys compute from SpaceX. Every lab pulls this lever when it suits them. This week it was OpenAI's turn to pull it and Anthropic's turn to look magnanimous.

Own your tool

The summary I gave on camera is that the dads are fighting and Cursor is caught in the middle. It is objectively a good product. I have used it and enjoyed it. And none of that protected its users from a decision made over their heads for reasons that have nothing to do with them.

The lesson is not "never use commercial tools." It is that the more of your stack you own, the less any of this touches you. Open harnesses and editors have gotten genuinely good, they are auditable, customizable, and nobody can revoke them: Jean, T3 Code, Superset, Herdr, OpenCode, the DeepSeek harness I reviewed, plugins you control inside VS Code. Personal impact of this news on my setup: none. That is not luck, it is the setup.