OpenAI notified SpaceX that it will wind down its contract providing models to Cursor, with a proposed shutoff date of November 12, 20262,3,7. The move follows SpaceX's $60 billion acquisition of the AI coding assistant, which closed on August 14.
OpenAI said it "cannot be confident that SpaceX will use our technology within our ToS," citing past contract violations by Elon Musk's companies. The company specifically referenced Twitter, now part of SpaceX, breaking its contract after Musk acquired it, and noted that Musk admitted under oath earlier this year that xAI had violated OpenAI's terms5,6. OpenAI's custom agreement with Cursor includes a limited cancellation window triggered by a change of control, which SpaceX's acquisition activated.
OpenAI said it will not provide future models to Cursor, including its upcoming model Astra. The company said it will "go above and beyond to support developers through the transition".
Cursor CEO Michael Truell responded on X, stating that OpenAI models account for about 5% of Cursor user traffic and that the companies are in discussions to resolve the matter. "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," Truell said.
Anthropic is positioning itself to fill the gap. Reuters reported that Anthropic plans to increase compute support for Claude models in Cursor. Anthropic co-founder and executive Tom Brown said Cursor has been a trusted partner of Anthropic since Sonnet 3.5. Anthropic is also now partnering with SpaceX and renting compute capacity from Musk's company.
The decision echoes Anthropic's own move last June, when it blocked Windsurf's access to Claude models while OpenAI was considering acquiring that company. ANALYSIS The parallel is direct: model providers are using access as leverage when coding-tool startups change hands to competitors.
Latent Space noted that both OpenAI and SpaceX's xAI have strengthened their competitive positions since Cursor first built on OpenAI's platform. GPT 5.6 is now described as a serious coding alternative to the Claude 5 series, and xAI's Grok 4.6 has become a viable coding model, with Grok Bot competing against Codex and ChatGPT.
Cursor, which competes with GitHub Copilot and other rivals, raised $2 billion in 2026 at a $50 billion post-money valuation. SpaceX had previously acquired Musk's X and xAI in February before going public in June.
The broader dispute between Musk and OpenAI runs deep. Musk co-founded OpenAI and helped fund it as a nonprofit research lab in 2015, then left the board in 2018. He sued OpenAI, Sam Altman, and Greg Brockman in 2024, lost the case earlier this year, and has vowed to appeal.
ANALYSIS The practical consequence for Cursor users is limited in the near term given the 5% traffic share, but the cutoff removes optionality from a tool that built its early product around OpenAI models. For coding-tool teams more broadly, the episode demonstrates that model-provider access can be revoked after ownership changes, making model portability and fallback capacity operational priorities.
The November 12 shutoff date represents the maximum notice allowed under the custom agreement.