OpenAI will wind down the contract that supplies its models to Cursor, with a proposed shutoff date of November 12 — four days from now — after SpaceX completed its $60 billion purchase of Cursor’s parent company, Anysphere, in August. OpenAI says it cannot be confident the new owner will use its technology within its terms of service. Cursor will keep working with models from Anthropic, Google and Grok, and its chief executive says OpenAI models account for about 5% of its traffic, while talks with OpenAI continue and the date itself remains a proposal rather than a confirmed deadline.
The deal behind the split
SpaceX agreed in June to buy Anysphere for $60 billion in an all-stock deal and closed the purchase on August 14. Two weeks later, on August 28, OpenAI notified SpaceX it intended to wind down the model-supply contract, calling November 12 the maximum notice its contract allows.
The move turned a corporate acquisition into a public break between two of the industry’s most powerful companies. It left Cursor — a leading AI coding editor — caught squarely between its new owner and one of its key suppliers.
Why OpenAI says it is walking away
OpenAI’s statement is unusually blunt. It says that after Musk acquired Twitter, now part of SpaceX, the company broke the terms of its contract with OpenAI, and that Musk admitted under oath earlier this year that xAI had violated OpenAI’s terms of service.
The company says its custom agreement with Cursor gives it only a limited window to cancel after a change of control. It also cites a new level of accountability for its upcoming Astra model, and says it chose the latest cancellation date the contract allows while withholding future models from Cursor in the meantime.
What changes for developers
From November 12, Cursor users will no longer get OpenAI models directly through the editor under the current arrangement. No new OpenAI models will arrive there before then, either — Cursor’s catalogue is frozen on the versions it already has.
The practical impact is limited. Cursor chief executive Michael Truell has said OpenAI models serve about 5% of Cursor traffic, and the editor keeps Anthropic, Google, Moonshot and Grok models. Anthropic has said it will keep increasing the Claude compute available to Cursor.
Users who rely on OpenAI models can switch to another model inside Cursor, use their own API key, or try its Codex extension. VS Code now runs Claude, Codex and Copilot side by side in one session, giving developers another multi-model home.
Our read: the precedent matters more than the 5%
The numbers say this is a smaller disruption than the headlines suggest: OpenAI models are only about 5% of Cursor traffic, and a four-year partnership is ending over ownership rather than product. But the precedent is the real story here.
A model provider has now shown it will cut off a leading tool over who owns it, using a change-of-control clause as the lever. That turns model access into a strategic weapon in the rivalry between labs, and it tells every tool builder that their supply of frontier models depends on their cap table as much as their product.
Cursor’s answer — leaning on Grok and its own models — shows where the market is heading: coding tools that own their models, or at least never depend on one supplier. Anthropic’s position underlines the point: the lab now carries much of Cursor’s load even as its own valuation slides toward $1.1 trillion ahead of its IPO.
Why It Matters
For developers, the deadline is practical: anyone writing code with OpenAI models inside Cursor should switch models or set up an alternative route before November 12. They should not assume the date will move — OpenAI has described it as the maximum notice available, and Cursor could end access sooner.
For the industry, the split is a warning that the AI stack is fragmenting along ownership lines. The coding assistant you use increasingly determines which models you can reach, and the companies that control the models are now willing to use that control.
Background
Cursor grew in barely two years from a small AI-first code editor into one of the defining tools of the agentic coding boom, and its rise helped make model choice inside the editor a competitive battleground for developers around the world.
SpaceX’s purchase in August folded it into Elon Musk’s empire alongside xAI and Grok, setting up the collision with OpenAI, whose chief executive Sam Altman and Musk have feuded publicly for years. OpenAI says it worked with Cursor for nearly four years and respects what its team built — but that history did not survive the change of ownership.
Source: OpenAI’s decision on Cursor and Reuters report on the split
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