Netplay Server

Node.js Netplay server for EmulatorJS

Fork

This server is forked from:

• repo: EmulatorJS-Netplay
• branch: main
• commit: 9e8a6e6eef47fc5bcea3b4b596ad233e4f8f35e9
• date: Sep 19, 2025
• license: Apache 2.0

Notes about the upstream repo:

• rust is now the default branch
• releases for v0.4.0+ include native binaries built with the Rust compiler
  • doesn't run on Win7

Requirements

• Node.js v18 or higher

Installation

npm install --global "@warren-bank/netplay"

Starting the Server

# default port: 3000
netplay

# custom port: 4000 (w/ command-line argument)
netplay 4000

# custom port: 4000 (w/ environment variable in bash)
PORT=4000 netplay

# custom port: 4000 (w/ environment variable in Windows cmd)
set "PORT=4000" && netplay

# custom port: 4000 (w/ environment variable in Windows PowerShell)
$env:PORT=4000; netplay

Usage with EmulatorJS

window.EJS_netplayServer = 'http://192.168.0.100:3000';
window.EJS_gameID = 123456;

References:

• Netplay server documentation
• issue EmulatorJS/EmulatorJS-Netplay#1
  • PR EmulatorJS/EmulatorJS#1053

Single Page App

EmulatorJS: Arcade Console emulator