OpenAI Ends Cursor Partnership
OpenAI revealed on Friday evening that it will terminate developers' access to its models through Cursor, a move that follows SpaceX's acquisition of the AI coding startup earlier this month. The planned cutoff date is November 12, 2026, and OpenAI will not supply future models, including its upcoming Astra model, to Cursor.[S1][S2][S4]
OpenAI explained that it cannot trust SpaceX to adhere to its terms of service, citing past instances where Elon Musk's companies breached contracts. The company pointed to Twitter's previous violation and Musk's admission under oath that xAI had used OpenAI's output to train Grok, which went against their agreement.[S1][S2][S4]
Cursor's Response and Impact
Cursor's CEO, Michael Truell, stated that OpenAI models account for roughly 5% of Cursor's user traffic, and they are in discussions with OpenAI to address the situation. He emphasized that Cursor was among the earliest adopters of OpenAI and had relied on their platform as impartial infrastructure.[S1][S2]
Developers who use OpenAI models through Cursor can still utilize their own OpenAI API keys, and OpenAI's IDE extensions for Cursor will remain functional. This action appears to be aimed specifically at Musk rather than the broader AI coding tool market.[S5]
Context of Musk-OpenAI Feud
This decision stems from the ongoing feud between Musk and OpenAI's leadership, including CEO Sam Altman and President Greg Brockman. Musk filed a lawsuit against OpenAI in 2024 over its transition from nonprofit to for-profit, and although he lost the case earlier this year, he has indicated plans to appeal.[S1][S2]
SpaceX finalized its $60 billion purchase of Cursor on August 14, as per financial filings. The acquisition grants Cursor access to SpaceX's computing resources, and together with SpaceXAI, Cursor launched Grok 4.5 in July, which is available on all plans.[S1][S3]
Industry Reactions and Implications
Anthropic, which is now partnering with SpaceX, responded by reaffirming its support for Cursor. Tom Brown, Anthropic's co-founder, said Cursor has been a trusted partner and they will continue to increase compute for Claude models in Cursor. This drew criticism from some tech executives, noting Anthropic's past actions with Windsurf.[S1][S5]
The move highlights how AI labs guard their model outputs and user data. OpenAI is refusing to feed a direct competitor that has been caught distilling its models. For developers, the lesson is that AI tools can be cut off due to corporate disputes, so having a fallback like a personal API key is crucial.[S6]
