Player builds

In the Editor, Loom loads the UI from a live Vite dev server. In a player build, that dev server does not exist. Loom loads a production UI bundle from:

Assets/StreamingAssets/Loom/

Automatic build hook

Loom runs the UI production build during every Unity player build:

1. Unity starts the player build.
2. Loom runs npm run build in your UI directory.
3. Loom copies the output to Assets/StreamingAssets/Loom/.
4. The player build includes that static bundle.

If the UI build fails, Loom aborts the player build.

Requirements

The build machine needs:

• Node.js 20+
• npm
• Installed UI dependencies (node_modules)
• A valid UI package.json with a build script

No Node.js in the shipped game

Node.js and Vite are development/build-time tools only. The shipped player loads static HTML, CSS, JavaScript, fonts, and assets from StreamingAssets/Loom.

Verify the output

After a build, confirm that Assets/StreamingAssets/Loom/index.html exists and that the folder includes the expected assets. If the Editor works but the player is blank, this folder is the first thing to check.

For automated builds, see CI/CD.