OpenAI Ends Model Access to Cursor After SpaceX Acquisition, Anthropic Expands Claude Capacity

OpenAI announced late Friday that it is winding down developers' access to its models on Cursor, the AI coding editor whose parent company Anysphere was acquired by Elon Musk's SpaceX earlier this month. The proposed cutoff date is November 12, 2026, and OpenAI said it will not provide future models to Cursor as the agreement winds down.

Why OpenAI Cut Cursor Off

SpaceX closed its $60 billion all-stock acquisition of Anysphere on August 14, according to financial filings. OpenAI cited a change-of-control clause in its custom contract and said it could not be confident that SpaceX would use its technology within the terms of service. "We are making this choice because we 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," the company wrote, referencing past disputes over Twitter and xAI.

Cursor's Response

Cursor co-founder and CEO Michael Truell said in a post on X that OpenAI models serve about 5 percent of Cursor user traffic and that the company is speaking with the OpenAI team to resolve the issue. "We're sorry to see that OpenAI put out a note saying they plan to block Cursor users from accessing OpenAI models in three months," he wrote. Cursor has positioned itself as model-agnostic, letting users tap GPT, Claude, Gemini, or others depending on the task.

Anthropic Seizes the Moment

Anthropic responded within hours. Co-founder and chief compute officer Tom Brown posted that Cursor has been a trusted partner of Anthropic since Sonnet 3.5 and that the company will continue to increase compute to support Claude models in Cursor. Separately, Anthropic is raising weekly usage limits for Claude Code by 25 percent on a permanent basis starting September 14 for Pro, Max, Team, and seat-based Enterprise plans, on top of an existing 50 percent temporary boost.

What Developers Should Watch

OpenAI's help center outlines workarounds, including personal API keys, the Codex IDE extension, and gateway integrations, though advanced Cursor capabilities such as Tab, Cloud Agents, and the CLI remain tied to provider-supplied models. Musk dismissed the dispute with a terse "couldn't care less" post on X, while Reuters noted the episode is the latest flare in a years-long feud between Musk and OpenAI leadership. The next several weeks will test whether Cursor can hold developer momentum and whether Anthropic's added capacity can absorb displaced traffic.