OpenAI’s proposed cutoff for Cursor falls on Thursday 12 November 2026, two days from now, and developers who rely on OpenAI models inside the popular coding editor should plan for the change. The date was set out by OpenAI in August, and neither company has confirmed a final arrangement since.

On Friday 28 August 2026, OpenAI published a post titled “Our decision on Cursor following its acquisition by SpaceX”, announcing that it would wind down the contract under which it supplies its AI models to Cursor, made by Anysphere. OpenAI proposed 12 November as the shutoff date for existing model access and said it would not supply any future models to the platform as the agreement winds down. CNBC reported the decision the following day.

Why OpenAI is ending the deal

The trigger was ownership. SpaceX completed a reported $60 billion all-stock acquisition of Anysphere on 14 August 2026, making Cursor part of a corporate family that includes xAI and its Grok models, a direct OpenAI competitor. OpenAI said its custom agreement with Cursor gave it a limited window to cancel after a change of control, and it chose to use it.

OpenAI was unusually blunt about its reason. “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. Musk co-founded OpenAI but left its board in 2018, and later sued the company over its for-profit restructuring. He lost that lawsuit earlier in 2026 and has said he intends to appeal.

OpenAI also pointed to its upcoming model, Astra, saying tighter accountability rules around the new model made it unwilling to extend access to a partner it does not trust. The company said it was giving the maximum notice its contract allowed, to give developers as much time as possible to adjust.

What Cursor has said

Cursor chief executive Michael Truell responded on X on the night of 28 August, saying OpenAI models account for about 5% of Cursor’s user traffic and that the two companies were talking to try to resolve the dispute. “Cursor was one of the very first users of OpenAI, we’ve worked closely with their team for years, and we’ve trusted their platform to be neutral infrastructure for our business,” he wrote.

Anthropic co-founder Tom Brown posted the same evening that Anthropic would increase computing capacity to support its Claude models in Cursor. Anthropic, Google and SpaceXAI’s own Grok models remain available in Cursor, so most users will be unaffected. The impact falls on the smaller group of developers whose workflows are built specifically around OpenAI models inside the editor.

What developers should do before Thursday

Three things remain unsettled. OpenAI has called 12 November a proposed shutoff date rather than a final one, and both sides say talks are continuing, so the cutoff may still change. OpenAI’s own help pages add that Cursor may choose to end access sooner. And no migration plan or refund arrangement for affected users has been disclosed.

Developers who use OpenAI models through Cursor should switch their model selection to Claude, Gemini or Grok before Thursday, or keep using OpenAI models with their own API key, which OpenAI says will continue to work in Cursor and through its IDE extensions. Workflows that depend on OpenAI models accessed directly through Cursor’s interface will stop working if the proposed cutoff takes effect as stated.

The episode is a warning for anyone building on a single provider’s models inside a third-party tool: when ownership changes, access can follow. For now, the outcome rests on whether the talks Truell described produce a revised arrangement before Thursday, or whether OpenAI’s proposed cutoff takes effect as written.

Sources: OpenAI — Our decision on Cursor following its acquisition by SpaceX and Evermx — OpenAI to Cut Off Cursor’s Model Access Nov. 12.