Announcing the Unity CLI: A new way to connect your tools and agents

[Treyrannosaurus-Rex]

We’ve been closely listening to the community’s feedback regarding how you connect your agents and external tools to Unity. You’ve been clear about the need for more reliability, runtime access, and the flexibility to use the agents you’re already paying for and prefer.

Today, we’re excited to introduce the Unity CLI, our new terminal-native path for connecting agents, CI pipelines, and custom tooling to Unity.

What is the Unity CLI?

The Unity CLI is designed to enable agentic workflows and automation directly from your terminal. We built it in direct response to developer feedback, focusing on creating a more predictable and extensible way to interface with Unity Editor and runtime environments.

Key Highlights:

• Fast: Unity CLI can run arbitrary code using the “eval” command, which uses the Roslyn compiler, bypassing long compilation times and domain reloads.

• Bring Your Own Agent: Whether you are using Claude, Codex, Copilot, or local models, the CLI is designed to integrate with your existing, preferred setup.

• Extendable: Write your own custom commands to provide your agents with tailored context about your specific projects and be more efficient.

• Direct Runtime Access: Beyond the Editor, the CLI enables you to drive the runtime in development builds, unlocking live debugging, game-state changes, and automated playtesting.

What about the Unity MCP?

Unity MCP remains fully supported for your existing setups. We know many of you are already using it, and we want to ensure continuity. For those just getting started or looking for a more robust, extensible, and terminal-native solution, the Unity CLI is our recommended path forward. To help with the transition, the CLI includes an “MCP Mode,” allowing you to leverage existing MCP-based agents without starting from scratch.

Pricing Update:

We want to remove barriers to innovation, so we are making these tools free! Both the CLI and MCP will be free, with no concurrency limits on the MCP server.

Getting Started:

For a deeper technical dive and to get started with your first terminal-native workflow, visit the official documentation here: Unity CLI Documentation

Check out the blog for more details.

We’re excited to see what you build with these new capabilities. Let us know what you think!

Introduction to the new Unity command line interface (CLI)

[ali7919mb]

how does the unity CLI “MCP Mode” work? Do i still need to set up the Unity MCP first?

[christophera_unity]

Hi @ali7919mb

The existing Unity MCP is not required. The Unity CLI MCP has commands to help you setup. Install the CLI and then use unity mcp --help to see what’s available

[Thaina]

I am curious, what is unity assistant mcp was being used for after this?

Do we still need it if we only need to do agent driven development in unity in the same manner as assistance if we just use it for observe and edit everything in unity?

What functionality was differed from this mcp and unity assistant mcp?

[theRTC]

Wow this looks incredible!

[christophera_unity]

Hi @Thaina

We created the Unity CLI MCP as a superior implementation. It’s built on the new Pipeline package that allows for robust CLI to Editor communication. With that comes better performance, better handling of focus and domain reloads, and the ability to communicate with multiple Editors seamlessly.

Directly calling the Pipeline package through the CLI is a better option, but we wanted to make sure we continued to provide an MCP for the users that rely on it.

Call unity pipeline --help to see what’s available. For example:

• unity command allows you to execute a built-in or custom command in the Editor
• unity eval allows you to execute arbitary C# in the Editor without domain reload

I hope that anwers your question!

[Cell-i-Zenit]

this is really cool.

surprises me that this is actually for free, but ofc really nice to see. Maybe unity is indeed going into the right direction

Is this already live? The presentation mentioned that teams will be onboarded, but this post doesnt mention it

[Treyrannosaurus-Rex]

Yup! You can install it through your package manager. The blog linked above has more info on getting started.

[Cell-i-Zenit]

Trying to run it inside the AI Chat window in Jetbrains rider using codex i get this error:

error: Uncaught (in promise) Error: EEXIST: file already exists, mkdir ‘C:\Users\MY_USERNAME\AppData\Roaming\UnityHub\logs’
fs.mkdirSync(LOG_DIR_PATH, { recursive: true });
^
at fixMkdirError (ext:deno_node/fs.ts:1:26599)
at Object.mkdirSync (ext:deno_node/fs.ts:1:28841)
at new LoggerFactory (file:///C:/Users/MY_USERNAME/AppData/Local/Temp/deno-compile-unity.exe/index.js:3168:6)
at Container.instantiate (file:///C:/Users/MY_USERNAME/AppData/Local/Temp/deno-compile-unity.exe/container-gRSTit4_.js:214:21)
at file:///C:/Users/MY_USERNAME/AppData/Local/Temp/deno-compile-unity.exe/index.js:3519:39

Not sure if this is really true because the AI returned this

My prompt was:

call C:\Users\MY_USERNAME\AppData\Local\Unity\bin\unity.exe --help in powershell

Running it in powershell works fine

EDIT: this is a codex issue because running

“C:\WINDOWS\System32\WindowsPowerShell\v1.0\powershell.exe” -Command “& ‘C:\Users\MY_USERNAME\AppData\Local\Unity\bin\unity.exe’ --help” works… nice

[TheOtherMonarch]

Very nice. I am very happy with this direction. In the past, I think Unity QA testers had to manually enter play mode. I think this will accelerate Unity’s internal bug fixing a lot. Thumbs up.

[Cell-i-Zenit]

what i think is missing, is a collection of prebuild AI skills installable via the CLI. It took a while to get the hang of it via AI, but expectation is ofcourse: “add a new game object to the currently opened scene” just works directly after installing

EDIT: giving the unity cli access to the Profiler and framedebugger would be golden. Maybe even let the CLI read/adjust shadergraph?

[bugfinders]

I can see a lot of jenkins users raising a beer to you. I love it, i like the idea of the bot adjusting the car etc, but I feel like somehow either i zoned out a bit and didnt follow entirely how thats setup that would be more the kind of use id love to see it for for me, is the fine tuning of balances of things in games

[christophera_unity]

Hi @Cell-i-Zenit

We’re working on creating skills here: GitHub - Unity-Technologies/skills: A collection of reusable skills for AI coding agents — prompts, slash commands, and tools built for Unity workflows · GitHub

We’re also planning on adding integrations with the profiler and frame debugger before the CLI goes GA!

[christophera_unity]

Hi @bugfinders

Fine-tuning is absolutely one of the strongest strengths of the CLI. It’s one of the biggest pain-points with using the Editor, so we invested heavily in perfecting this flow.

The CLI is designed to be the gateway to Unity. With the idea that any dev/tool/script/cicd/agent could drive everything Unity from a single place. One thing we’re planning is a blog post on is how the CLI supercharges CICD workflows. I’m particularly proud of our single command for installing the correct Editor, running headless Editor/Player tests, and then reporting the results back.

[bugfinders]

it is a very awesome tool, you should be proud, while i am a hobbiest and therefore less likely to make use of some of its features, i have (as my boss would say) a big brain, and i can see some really great stuff coming due to your work, it is like the stargate, a portal to many things to come..

[Lurking-Ninja]

Just please always keep in mind us, who aren’t interested in AI-based workflows but we love to build our automations ourselves. So I really hope the CLI will be kept AI-independent in the sense it will always work without any kind of AI integration.

BTW, since I’m usually super-critical to Unity in the last, I don’t know, 4 years or so… Unity CLI is awesome! I really love it, thank you for making this! Also thank you for making this AI-agnostic so far, I love the traditional automation (Jenkins and whatnot), but until now these things were convoluted with Unity and wasn’t even clear what kind of licenses we needed to automate stuff on the more indie side of the things. This feature is great and I can’t wait where you take this further!

Love it!

[joeee19]

I haven’t tried it yet, but as someone who has spent the past year using AI extensively with Godot because Unity didn’t support it, this is the amazing decision I’ve been waiting for!

Unity’s stock price is going to rise. Honestly, it would be strange if it didn’t.

This will probably create some real magic, and we may start seeing one incredibly unique game after another.

I’d also love to see more official Unity skills, official plugins for OpenAI, and other first-party AI integrations!

[sonanlines]

That’s awesome ! It’s my favorite part of Unite Seoul 2026