OpenAI said Friday it will wind down its partnership with Cursor, the popular AI coding tool now owned by SpaceX, marking the latest escalation in the long-running dispute between OpenAI CEO Sam Altman and Elon Musk.
In a company blog post, OpenAI said it notified SpaceX of its intent to end the contract, proposing a shutoff date of Nov. 12, 2026 — the maximum notice window allowed under the agreement.
OpenAI framed the decision as a matter of trust. The company said it could not be confident that SpaceX would use its technology in accordance with OpenAI’s terms of service, citing what it described as a pattern of Musk’s companies violating contracts. Specifically, OpenAI’s post alleged that X breached the terms of its own contract with OpenAI after Musk’s acquisition, and noted that Musk had admitted under oath earlier this year that xAI had also violated OpenAI’s terms of service.
OpenAI added that its custom agreement with Cursor only gave it a limited window to cancel following a change of ownership, and said it wanted to preserve as much access as possible for developers in the meantime, calling the choice “incredibly tough” given how widely it wants its models used.
SpaceX completed its acquisition of Anysphere, the startup behind Cursor, earlier this month, following a deal announced in June.
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Responding on X, Musk wrote that he “couldn’t care less,” while calling Altman and OpenAI president Greg Brockman “untrustworthy” and repeating his long-standing claim that the pair “stole an open source nonprofit.” Michael Truell, Cursor’s co-founder and now a SpaceX executive, struck a more conciliatory tone, saying on X that the company was in talks with OpenAI’s team to try to resolve the issue.
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Since the announcement, OpenAI competitor Anthropic — which has an ongoing partnership with SpaceX — said it would increase compute support for its Claude models within Cursor.
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This is only the latest chapter in a feud that has simmered for years. Musk sued OpenAI and Altman for $150 billion over the company’s shift from its nonprofit roots; a federal jury ruled against him earlier this year, finding he’d filed too late.
The fight has also played out repeatedly on social media, as Mashable has reported. Altman reposted allegations that Musk’s companies failed to preserve key documents during discovery, then turned Musk’s own catchphrase back on him: “Concerning!” He later said he was “really excited” to depose Musk, calling it “Christmas in April.”
Disclosure: Ziff Davis, Mashable’s parent company, in April 2025 filed a lawsuit against OpenAI, alleging it infringed Ziff Davis copyrights in training and operating its AI systems.
