OpenAI is ending developers’ access to its models on Cursor, the AI coding assistant SpaceX acquired in a roughly $60 billion all-stock deal closed on August 14, with a proposed shutoff date of November 12, 2026, and no future models—including next-generation Astra—to be supplied through the platform. OpenAI said it notified SpaceX after the Anysphere acquisition triggered a change-of-control clause and that it cannot be confident SpaceX will use its technology within its terms of service, citing past disputes with Elon Musk’s companies, including X blocking OpenAI data access and xAI’s alleged use of OpenAI outputs to train Grok—something Musk later described in testimony as partly true. Cursor has not been accused of breaching the agreement. Cursor co-founder Michael Truell, now a SpaceX executive, said OpenAI models account for about 5% of user traffic, talks with OpenAI continue, and Cursor already runs a multi-model stack spanning Anthropic, Google, SpaceXAI, and others. Musk replied that he does not care, attacked Sam Altman and OpenAI president Greg Brockman as untrustworthy, and repeated claims they stole an open-source nonprofit; those claims stem from his 2024 lawsuit seeking about $150 billion in damages, which a federal jury rejected in May on statute-of-limitations grounds and which he has said he will appeal. Anthropic co-founder Tom Brown said Anthropic will expand Claude compute on Cursor, deepening competition among model providers even as Anthropic previously cut Claude supply to Windsurf and now leases compute into the Musk ecosystem. OpenAI said it will support developers through the transition after November 12.