The combined photo shows OpenAI CEO Sam Altman (left) on April 28, 2026, and Elon Musk on April 29, 2026, during the trial of Elon Musk’s lawsuit over OpenAI’s commercialization in federal court in Oakland, California.
Manuel Orbegoso | Reuters
OpenAI announced late Friday that it would end developer access to its models on Cursor following Elon Musk’s acquisition of the AI coding startup. space x Early this month.
“OpenAI models serve approximately 5% of Cursor user traffic, and to solve this We are in discussions with the penAI team. Cursor was one of the first users of OpenAI, and we have worked closely with their team for years and have trusted their platform to be a neutral infrastructure for our business.”
“We are making this choice because we have no confidence that SpaceX will use our technology within the scope of its terms of service, based on Elon Musk’s company’s history of breaching contracts,” OpenAI said in a statement.
The “proposed end date” for OpenAI models via Cursor is November 12, 2026. OpenAI also said it will not provide future models to Cursor as the contract ends.
Cursor and OpenAI did not immediately respond to CNBC’s requests for comment.
SpaceX completed its $60 billion acquisition of Cursol on Aug. 14, according to financial filings. SpaceX acquired Musk’s X and xAI in February before going public in June.
OpenAI’s exit from Cursor, now owned by SpaceX, is part of a long and acrimonious conflict between Musk and OpenAI CEO Sam Altman and president Greg Brockman.
In a post to X on Saturday, Musk used expletives to describe them, saying, “I don’t care. Fraud Altman and Greg Stockman are completely untrustworthy,” before repeating his claim that they “stole open source nonprofits.”
Musk sued OpenAI, Altman and Brockman in 2024 after co-founding and helping fund the AI company as a nonprofit research institute in 2015.
Musk left OpenAI’s board in 2018 after hiring from within the company, cutting off donations he had pledged to OpenAI, and clashing with his fellow board members over direction. He later became one of its most prominent critics.
After Musk left, OpenAI launched a highly successful AI product, namely ChatGPT, and partnered with leading technology companies, including: microsoftalong with its non-profit parent company, transformed the business into a for-profit company and raised a significant amount of capital.
Musk said in court that OpenAI’s reorganization violates its founding promise and that the changes amount to “theft of charity.” OpenAI disputes his claims. Although he lost the lawsuit earlier this year, Musk has vowed to appeal.
CNBC previously reported that OpenAI is poised to go public next year as the market for “vibecoding” (an AI-assisted coding tool) heats up, while rival Anthropic is holding preliminary meetings with bankers ahead of a possible IPO this year, with an expected valuation of as much as $2 trillion.
OpenAI’s choice to end developer access to models via Cursor is not the first in the industry.
Last June, Anthropic (which currently partners with SpaceX and rents computing power from Musk’s company) blocked Windsurf’s access to its Claude AI model.
“Cursor has been a trusted partner for Anthropic since Sonnet 3.5, and we continue to enhance our compute to support Cursor’s Claude model and are excited about future developments at SpaceX,” Anthropic co-founder and executive Tom Brown wrote in a post on X Friday night.
His post drew criticism from some tech executives about X, with Replit CEO Amjadmasad reminding Brown of Anthropic and Windsurf’s history, and Docker executive Mat Velloso responding, saying, “This was a great opportunity to stay silent.”
