OpenAI said on August 29 that it will stop supplying its AI models to Cursor, the popular AI coding assistant, after SpaceX completed its $60 billion, all-stock acquisition of Cursor’s maker, Anysphere — a deal the companies agreed to in June and formally closed on August 14. The wind-down takes effect November 12, according to an OpenAI post titled “Our decision on Cursor following its acquisition by SpaceX.”
OpenAI said it could not be confident that Elon Musk’s companies would keep honoring its terms of service going forward. It cited two precedents: Musk cutting off OpenAI’s access to Twitter’s data after buying the platform, and Musk’s other AI venture, xAI, training its Grok models on distilled outputs from rival systems in violation of OpenAI’s usage terms — something Musk acknowledged under oath in a separate legal proceeding, OpenAI said.
A safety rationale, too
OpenAI tied the decision partly to its unreleased Astra model. Internal testing reportedly found Astra’s agentic coding and cybersecurity capabilities strong enough that the company could not rule out a “Critical” rating under its own safety framework — a threshold OpenAI said calls for tighter control over access rather than distribution through a coding tool now owned by a competitor.
Limited near-term impact
Cursor co-founder Michael Truell said OpenAI’s models account for only about 5% of traffic on Cursor’s platform, and that the company is working with OpenAI’s team on a transition. Developers keep access to OpenAI models in Cursor until the November cutoff, and can still reach them afterward with their own OpenAI API keys — just not through Cursor’s built-in subscription plans. SpaceXAI’s Grok 4.5 is already available on every Cursor tier.
The move follows SpaceX’s $60 billion acquisition of Cursor this month, folding one of the most widely used AI coding tools into Musk’s expanding AI and rocket empire alongside xAI and Tesla.