# Build Unity3D project from source without Unity Editor

I am trying to create an installer which will download the source of the latest release of a Unity project from a repository hosted on Github and then build it into an executable file. I have tried looking online for a solution, but, they all require the Unity Editor to be installed.

Is it possible to build a Unity project from the source code into a .exe file or a .dmg file without the Unity Editor?

EDIT: From @DMGregory's answer, it seems that using an external tool to build Unity Projects will violate Unity's Terms of Service. Therefore, I am updating the question.

Does Unity provide a lightweight (installer) tool that can allow clients to build and install Unity projects from source rather than requiring the client to install the entire Unity Editor?

• Why not just build the project yourself when you update it, and have your installer grab the latest build from your server? This is likely to be less to download in total than the entire source, assets, and build pipeline, and give you more reliable results. – DMGregory Jun 6 '20 at 12:41
• From my point of view, I thought it would be easier to let an installer dynamically build from the project source to the target platform rather than me building the project from the editor to multiple platforms and uploading the built executable. But after seeing your answer, it would go against Unity's terms of service. – SidS Jun 6 '20 at 12:53
• You'll have to compile for each target platform to test your game anyway, so doing these builds doesn't add more work for the developer before releasing an update. – DMGregory Jun 6 '20 at 13:12

Unity's approved method for compiling the source of a Unity project into an executable is to install the Unity Editor - compiling either locally, or using it to communicate with a build server / cloud. That's the only method they offer or authorize.

If anyone were to provide a tool separate from the Unity Editor that could build Unity projects without a licensed Unity Editor installation, it would violate the Unity terms of service:

2.6 General Restrictions.

• By definition, a modding tool can only give access to Unity runtime functionality, not the Unity editor software functionality. You can't use an in-game level editor to, say, compile a new set of cross-platform game executables. A good rule of thumb: if it's in the UnityEditor namespace, it's not runtime functionality and may fall under this clause. – DMGregory Aug 22 '20 at 16:35