Set up your Node.js server configuration for Web builds

Create a Node.js server configuration file that lets your Node.js server work with your Unity Web build.

Node.js is an open-source runtime environment that lets you execute JavaScript code on the server side. In Unity, you can use a Node.js app to serve your Unity Web build.

For more information about Node.js and how to install and use it, refer to the Node.js documentation.

Set up your package.json file

To create a package.json file that’s ready for use with Unity Web:

Create a file in a text editor or IDE.
Name the file package.json.
Save your file in your Node.js project directory.

Paste the following code into the file:

{
  "name": "node_server_example",
  "version": "1.0.0",
  "description": "An example for serving a Unity Web build with Node.js",
  "main": "index.js",
  "dependencies": {
    "express": "^4.19.2"
  }
}

Your package.json file is now ready for use. The code defines the index.js file as your server project’s entry point, and defines the libraries your project will depend on.

Set up your index.js file

To prepare your index.js file for use with Unity Web:

Create a file in a text editor or IDE.
Name the file package.json.
Save your file in your Node.js project directory.

Paste the following code into the file:

#!/usr/bin/env node
const path = require('path');
const express = require('express');

// Create express application
const app = express();

// Settings
const hostname = 'localhost';
const port = 8080;
const enableCORS = true; 
const enableWasmMultithreading = true;


// Serve the current working directory 
const unityBuildPath = __dirname; // Note: this makes the current working directory visible to all computers over the network.

app.use((req, res, next) => {
    var path = req.url;

    // Provide COOP, COEP and CORP headers for SharedArrayBuffer
    // multithreading: https://web.dev/coop-coep/
    if (enableWasmMultithreading &&
        (
            path == '/' ||
            path.includes('.js') ||
            path.includes('.html') ||
            path.includes('.htm')
        )
    ) {
        res.set('Cross-Origin-Opener-Policy', 'same-origin');
        res.set('Cross-Origin-Embedder-Policy', 'require-corp');
        res.set('Cross-Origin-Resource-Policy', 'cross-origin');
    }

    // Set CORS headers
    if (enableCORS) {
        res.set('Access-Control-Allow-Origin', '*');
    }    

    // Set content encoding depending on compression
    if (path.endsWith('.br')) {
        res.set('Content-Encoding', 'br');
    } else if (path.endsWith('.gz')) {
        res.set('Content-Encoding', 'gzip');
    }

    // Explicitly set content type. Files can have wrong content type if build uses compression.
    if (path.includes('.wasm')) {
        res.set('Content-Type', 'application/wasm');
    } else if (path.includes('.js')) {
        res.set('Content-Type', 'application/javascript');
    } else if (path.includes('.json')) {
        res.set('Content-Type', 'application/json');
    } else if (
    path.includes('.data') ||
    path.includes('.bundle') ||
    path.endsWith('.unityweb')
    ) {
        res.set('Content-Type', 'application/octet-stream');
    }

    // Ignore cache-control: no-cache 
    // when if-modified-since or if-none-match is set
    // because Unity Loader will cache and revalidate manually
    if (req.headers['cache-control'] == 'no-cache' &&
    (
        req.headers['if-modified-since'] ||
        req.headers['if-none-match']
    )
    ) {       
        delete req.headers['cache-control'];
    }        

    next();
});

app.use('/', express.static(unityBuildPath, { immutable: true }));

const server = app.listen(port, hostname, () => {
    console.log(`Web server serving directory ${unityBuildPath} at http://${hostname}:${port}`);
});

server.addListener('error', (error) => {
    console.error(error);
});

server.addListener('close', () => {
    console.log('Server stopped.');
    process.exit();
});

If your build loads via CORS (for example, embedded on different website), then set the following line in your code to true, otherwise set it to false:
```
const enableCORS = true; 
```
If you created your build with multithreading support, set the following line in your code to true, otherwise set it to false:
```
const enableWasmMultithreading = true;
```

Your server configuration is now ready for use with Unity Web builds.

Additional resources

Set up your Nginx server configuration for Web builds

Windows

Unity Manual

Set up your Node.js server configuration for Web builds

Set up your package.json file

Set up your index.js file

Additional resources