OpenAI Terminates Billion-Dollar Cursor Partnership After SpaceX Acquisition
OpenAI ended its relationship with AI coding startup Cursor, citing inability to trust Elon Musk's companies to comply with terms of service.
What happened
OpenAI announced in a late-night blog post that it would wind down its partnership with Cursor, the AI coding editor startup acquired by SpaceX. At the start of 2026, Cursor was one of OpenAI's top five revenue-generating customers; by spring 2026, OpenAI estimated the partnership would generate over $1 billion in annualized revenue. OpenAI stated it made the decision because it "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." Cursor founder and CEO Michael Truell, now leading teams at SpaceX, responded that OpenAI's models only serve about 5% of Cursor user traffic. OpenAI's head of core products challenged this claim, noting that token usage is not a proxy for revenue or value created.
Context
OpenAI is preparing for a public offering next year and appears to prioritize demonstrating business stability and investor confidence over retaining major revenue sources tied to Musk. The company reported over $40 billion in annualized revenue across multiple lines of business, suggesting Cursor's loss, while significant, may not be catastrophic financially. However, the termination damages OpenAI's standing with developers—a constituency it has cultivated for years—by severing a major distribution channel for its models. Cursor and OpenAI had operated as both partners and competitors for over a year, with OpenAI having been an early investor in Cursor's 2023 seed round and reportedly attempting an acquisition at one point. The breakup reflects OpenAI's concern that SpaceX may extract and repurpose OpenAI's proprietary models, a worry the company grounded in Musk's apparent admission during his deposition that xAI used OpenAI's models for training. Anthropic, by contrast, announced it would continue providing Claude models to Cursor—a decision that may be influenced by Anthropic's $45 billion data center capacity dependence on SpaceX.
What's disputed
The significance of OpenAI's models to Cursor's user base is contested. Cursor claims OpenAI models represent only 5% of user traffic, while OpenAI questions whether this metric reflects actual revenue value or business impact.