OpenAI Models Leave Cursor on 12 November as Cursor Ships Agent SDK

Cursor users lose access to OpenAI's models on 12 November 2026, two days from now, unless the two companies reach a deal first. OpenAI announced the move late on 28 August, two weeks after SpaceX completed its $60 billion acquisition of Cursor maker Anysphere, saying "we cannot be confident that SpaceX will use our technology within our terms of service." Cursor's response since then has been to ship: an Agent SDK declared generally available on 20 October, an Environments API, and on 5 November the ability for cloud agents to build and host live apps. I think this is the clearest case yet of a model supplier's politics landing directly in developers' editors.

What happened

The sequence, from CNBC, Engadget and Techzine:

• 16 June 2026: SpaceX agreed to buy Anysphere for $60 billion, Techzine reported, a few days after SpaceX's Nasdaq listing. SpaceX had merged with xAI earlier in the year.
• 14 August: the acquisition completed, according to financial filings cited by CNBC.
• 28 August: OpenAI said it would end its contract supplying models to Cursor, proposing 12 November as the shutoff date. Techzine reported that OpenAI invoked a change-of-ownership clause and chose the latest end date it allowed. OpenAI also said no future models, including its Astra model, would be offered through Cursor.
• Cursor's position: CEO Michael Truell wrote that "OpenAI models serve about 5% of Cursor user traffic, and we're speaking with the OpenAI team to resolve this." Anthropic co-founder Tom Brown said Anthropic would keep increasing compute for Claude in Cursor.

OpenAI pointed to Elon Musk's companies' history with its contracts, including Musk's admission under cross-examination that xAI had used OpenAI outputs to train its models, per Engadget. Musk said on X that he "couldn't care less," CNBC reported. I found no announcement of a settlement as of 10 November, and coverage at the time described 12 November as a proposed date.

What Cursor shipped in October and November

The Cursor changelog for the period reads like a company building a platform that does not depend on any single model vendor:

• 13 October: a marketplace for its Origin code-hosting product with over 20 integrations, including Cloudflare, Linear, Sentry and Socket Security.
• 16 October: cloud agents can build shareable "canvases"; an Environments API (beta) manages agent cloud environments programmatically; environments now support up to 300 repositories and large ones load 5x faster.
• 20 October: the Agent SDK went GA. An agent is a folder of code: Markdown prompts, TypeScript tools and evals, deployed with agent-sdk deploy to Cursor or run as a single Node process on your own infrastructure. Agents respond to events such as pull requests on GitHub, GitLab and Bitbucket. Cursor says it builds Bugbot, Security Reviewer and Rollouts on it.
• 5 November: live apps. A cloud agent scaffolds a web app, provisions Postgres, puts auth behind Cursor SSO and hosts it. Publishing runs deterministic and agentic security checks, and nothing goes live until they pass and a person publishes.
• 6 November: realtime voice calls with agents.

The numbers

Why it matters

Five percent of traffic is small for Cursor and large for whoever is in it. If your team standardised on a GPT model inside Cursor for a particular workflow, that workflow changes this week regardless of how the commercial talks end. And the bigger point is precedent. Model access through a tool is a contract between two vendors, not between you and either of them. In June 2025 Anthropic limited Windsurf's access to Claude, as CNBC noted, and now OpenAI has done the same to Cursor. Ownership changes and rivalries can switch off a model you rely on with about eleven weeks' notice.

The Agent SDK is the other half of the story. Agents defined as code with evals, deployed to Cursor or to your own containers, is a sensible design, and being able to run them as a plain Node process means the runtime is yours if you want it. It also nudges teams to build automation inside Cursor's platform at the moment its model supply has become a governance question.

What sceptics say

From the Cursor side, the effect may be small. Other models remain available in Cursor, and Anthropic has publicly backed continued supply. OpenAI itself called 12 November a proposed date and Cursor said it was talking to OpenAI, so the date could move.

From the customer side, analysts quoted by InfoWorld warned that switching models is not free. Prompts, agent configurations and evals tuned for one model may behave differently on another, and one analyst expected a short-term productivity dip while teams retune. Pareekh Jain put it bluntly: enterprises "can no longer assume that a model available through an AI coding platform today will always remain available."

What it means for engineering and DevOps teams

• Find your OpenAI dependencies in Cursor today. Check team settings, rules files and any automations or agents that pin a GPT model, and switch them before 12 November rather than discovering failures after.
• Re-run your evals on the replacement. If you have an eval set for code review or test generation, run it against the new model and compare. If you do not have one, this is the week to write ten cases.
• Keep the agent definition portable. Prefer configs where the model is a single parameter, and keep prompts and tools in your own repo. The Agent SDK's folder-of-code model helps if you treat it that way.
• Add model availability to vendor reviews. Ask every AI tool vendor which models it resells, under what contracts, and what notice you get if one is withdrawn. My coding agents market overview has the wider context.

FAQ

When do OpenAI models stop working in Cursor?

OpenAI proposed 12 November 2026 as the shutoff date for its models in Cursor. Current models remain until then, and OpenAI said future models such as Astra will not be added while SpaceX owns Cursor. Cursor said it was talking to OpenAI, and no resolution had been announced by 10 November.

Why is OpenAI removing its models from Cursor?

OpenAI said it cannot be confident that SpaceX, which completed its acquisition of Cursor maker Anysphere on 14 August 2026, will use its technology within OpenAI's terms of service. It cited past disputes with Elon Musk's companies, which include xAI.

What is the Cursor Agent SDK?

It is a framework, generally available since 20 October 2026, for defining agents as code: Markdown instructions, TypeScript tools and evals in one folder. Agents can be deployed to Cursor's infrastructure or run as a Node process in your own container, triggered by events such as pull requests on GitHub, GitLab or Bitbucket.

Related: Coding Agents in 2026: Cursor at $2B Then Sold to SpaceX, How to Write AGENTS.md and CLAUDE.md Files Agents Follow and How to Run LLM Evals in CI with GitHub Actions.