OpenAI has severed its relationship with Cursor, an AI coding editor, after SpaceX acquired its parent company Anysphere in a $60 billion all-stock deal completed in August 2026. The termination marks a dramatic escalation in the long-running feud between Sam Altman and Elon Musk, two founders who started OpenAI together in 2015 but have been locked in legal battles and public disputes for years.

On August 28, OpenAI notified SpaceX that it would wind down the contract supplying its models to Cursor, with a proposed shutoff date of November 12. The company stated it would supply no new models during the wind-down period. Cursor's parent company, Anysphere, had been among OpenAI's earliest customers, and the two had worked together for close to four years before the acquisition changed everything.

Why Did OpenAI Cut Off SpaceX's Access?

OpenAI's stated reason was not about performance or technical capability. Instead, the company cited trust concerns, saying it could not be confident that SpaceX would use its technology within the terms of service. OpenAI pointed to a troubling history of contract breaches at Musk-owned businesses, including Twitter's conduct after Musk's takeover and, more pointedly, Musk's own admission under oath earlier in 2026 that xAI had violated OpenAI's terms of service.

The company also invoked its forthcoming model, Astra, which OpenAI said in August may reach a critical cyber capability threshold under its own preparedness framework. This development, OpenAI argued, justified tighter control over who receives access to its most advanced systems. Cursor's custom agreement with OpenAI allowed only a narrow window to cancel following a change of control, and the company used the full notice period available under that clause.

"OpenAI models account for roughly 5% of Cursor traffic and discussions were under way," said Michael Truell, Cursor co-founder and now a SpaceX executive, taking a conciliatory tone.

Michael Truell, Cursor Co-founder and SpaceX Executive

Musk's response was far less diplomatic. On X, he said he could not care less about the termination, described Altman and OpenAI president Greg Brockman as untrustworthy, and repeated his charge that the pair took an open-source nonprofit and converted it for personal enrichment. Anthropic, OpenAI's rival, moved within hours to capitalize on the situation, with co-founder Tom Brown signaling additional compute for Claude models inside Cursor.

How Did This Decade-Long Rivalry Begin?

To understand why a routine contract termination read as an act of war, you have to trace back to 2015, when Musk and Altman founded OpenAI together as a nonprofit with an explicit mission: to stop advanced artificial intelligence from ending up under the control of any single company. Musk contributed tens of millions of dollars to the venture. By 2017, the founders had concluded they could neither raise the capital nor recruit the researchers needed to compete without a commercial arm.

Musk accepted the diagnosis but wanted the cure on his own terms, proposing either a majority stake in the for-profit entity or folding the whole thing into Tesla. Altman, Brockman, and Ilya Sutskever refused. Musk left the board in 2018, took talent with him, and stopped the donations he had promised. The grievance stayed largely private for five years.

Key Milestones in the Musk-Altman Conflict

• July 2023: The feud went public with the launch of xAI, Musk's own artificial intelligence company, signaling his determination to compete directly with OpenAI.
• February 2024: Musk sued in California state court, alleging that Altman and Brockman had manipulated him into bankrolling a charity they then converted for personal enrichment.
• June 2024: Musk withdrew the California case and refiled in federal court in August, continuing his legal assault on OpenAI's leadership.
• January 2025: Altman appeared alongside Donald Trump to announce Stargate, a $500 billion AI infrastructure program, without warning Musk, who was by then running the Department of Government Efficiency.
• April 2025: OpenAI countersued, calling Musk's bid for the company's assets a feint and describing a sustained campaign of harassment waged through press attacks and posts to more than 200 million followers on X.
• August 2025: xAI and X sued Apple and OpenAI in Texas, arguing that the Siri partnership made it impossible for any rival assistant to reach the top of the App Store.

The legal battles have multiplied across multiple fronts. In August 2025, xAI sued OpenAI over engineer poaching and trade secrets. That case was dismissed in February 2026 with leave to amend, dismissed again in June without it, and is now before the Ninth Circuit. The antitrust case survived dismissal in November 2025 and remains active.

The Cursor termination also arrives amid other complications for OpenAI. On the same day the company announced that ChatGPT Ads had reached $1 billion in annualized revenue run rate, Apple filed a forensic complaint in federal court alleging that a former Apple engineer accessed proprietary power converter schematics while working at OpenAI and trained an artificial intelligence agent on Apple's unreleased product specifications in March 2026. The evidence surfaced on a MacBook that OpenAI itself handed over during the discovery process, prompting Apple to request expedited discovery.

Despite the litigation, the commercial relationship between Apple and OpenAI survives uncomfortably. ChatGPT remains an option inside Siri and Apple Intelligence, and Apple's complaint expressly carves the integration agreement out of the dispute. The backdrop is OpenAI's roughly $6.5 billion purchase of io Products in 2025, which brought Jony Ive and a cohort of former Apple engineers inside the company that Apple now accuses of systematic misappropriation.

What Does This Mean for the Future?

The Cursor termination signals that the Musk-Altman rivalry has moved beyond courtroom disputes and public insults into the realm of direct business retaliation. OpenAI's decision to cut off SpaceX demonstrates that the company is willing to sacrifice business relationships to prevent Musk-controlled entities from accessing its most advanced technology. For Cursor users and Anysphere employees, the immediate impact is clear: they will need to transition to alternative AI models, with Anthropic's Claude positioned as the primary replacement.

The broader implications extend to the artificial intelligence industry itself. The conflict between Musk and Altman represents a fundamental disagreement about how advanced AI should be developed and controlled. Musk's original vision for OpenAI as a nonprofit safeguard against concentrated AI power has given way to a for-profit company that Musk now views as having betrayed its founding principles. OpenAI's actions suggest the company believes that controlling access to its most powerful models is essential to ensuring they are used responsibly, even if that means cutting ties with major customers.