OpenAI to end model access to Cursor after SpaceX acquisition

OpenAI announced late Friday that it is terminating developers' access to its models on Cursor, the AI coding startup recently acquired by Elon Musk's SpaceX. The proposed cutoff date for OpenAI model access via Cursor is November 12, 2026.

Key Details

• OpenAI plans to wind down its contract supplying models to Cursor, with a proposed Nov. 12 cutoff.
• OpenAI stated it cannot be confident that SpaceX will comply with its terms of service, citing past disputes with Elon Musk's companies.
• Cursor CEO Michael Truell confirmed that OpenAI models account for approximately 5% of Cursor user traffic and said the companies are in discussions regarding the decision.

Statements from Both Sides

Cursor CEO Michael Truell posted on X (the SpaceX-owned social network) Friday night:

"OpenAI models serve about 5% of Cursor user traffic, and we're speaking with the OpenAI team to resolve this. 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."

OpenAI said in its announcement:

"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."

OpenAI also confirmed it will not provide future models to Cursor as it winds down the agreement.

Background: The Musk-OpenAI Rivalry

The decision is the latest chapter in a long-running and acrimonious dispute between Elon Musk and OpenAI leadership, including CEO Sam Altman and President Greg Brockman.

• Musk co-founded OpenAI in 2015 as a non-profit research lab and helped fund it.
• He left OpenAI's board in 2018 after hiring talent away from the company, cutting off promised donations, and clashing with fellow board members over its direction.
• Musk later became one of OpenAI's most prominent critics.
• After Musk's departure, OpenAI launched ChatGPT, partnered with Microsoft, converted to a for-profit structure with a non-profit parent, and raised substantial funding.
• Musk sued OpenAI, Altman, and Brockman in 2024, arguing the restructuring violated founding commitments. He lost the lawsuit earlier this year but has vowed to appeal.

In a post on X Saturday, Musk wrote:

"I couldn't care less. Scam Altman and Greg Stockman are utterly untrustworthy," adding an expletive and repeating his claim that they "stole an open source nonprofit."

Acquisition Details

SpaceX completed its $60 billion acquisition of Cursor on August 14, 2026, according to financial filings. Before SpaceX went public in June, it had acquired Musk's X and xAI in February.

Industry Context

OpenAI's move to end model access via Cursor is not unprecedented in the industry. Last June, Anthropic — now partnering with SpaceX — took a similar step.

As the market for "vibe coding" (AI-assisted coding tools) intensifies:

• OpenAI is poised to go public next year.
• Rival Anthropic has held preliminary meetings with bankers ahead of a possible IPO this year, with an expected valuation as high as $2 trillion, according to CNBC.

Response Status

Cursor and OpenAI did not immediately respond to CNBC's requests for comment.