Hello there, everyone. I’ve been working with Unity for the past several months and I started using MCP’s a while back. I use both Claude and Codex, and both will trigger full asset reimports in the middle of tasks and it sets me back a good two hours every time because there’s no way to stop the reimport…and even if you force close Unity, the editor will just start the reimport again once you try to reopen it, and it won’t load in until it’s finished. It’s dirty, it’s mean, and I need a way to stop it. lol. Perhaps Unity can implement a way to cancel reimports, or work with the Anthropic and OpenAI to stop their AI’s from doing this?
You need to use the Unity CLI (Command-Line Interface) instead of the MCP Server now because it was deprecated.
The Unity CLI lets AI agents work with Unity from the terminal directly with files. It can manage Editors, projects, packages, builds, and more without requiring the Editor to be running.
For controlling a running Unity Editor and working directly with the Unity Project, the CLI uses the Unity Pipeline package, which provides a local API for Editor automation. Unity CLI includes its own MCP server built on the Unity Pipeline package.
In addition, to complete the picture around the Unity Pipeline package and CLI, Unity recently released official plugins for Claude and Codex that work via this bunch of tools.
After installing the plugin, your agent uses skills — curated and maintained by Unity engineers — to load the relevant context and accomplish the tasks you give it in your Unity project.
Ask the agent that you were working with why it triggered a full reimport. Perhaps the agent is acting on an instruction from you that it misunderstood as “reimport all” whenever it finishes work.
Also worth noting and VERY important: do not let an agent work within the same project that you currently have open. Especially if you work yourself within that project in parallel.
The agent should be working in its own copy, and source control is used to merge the agent’s changes into your project. Install Unity CLI and the Unity Pipeline package and tell the AI to use it, and to run its own Unity instance headlessly (whenever it can) so it won’t even bother you with window popups.
Thank you very much. Heck yes. Stay frosty
Thank you, I appreciate the guidance–live long and prosper.