Minecraft Modpack Server

Modded Minecraft Server Setup

Set up and manage a NeoForge or Forge modded Minecraft server on Windows. Covers server installation, modpack configuration, memory tuning, and startup automation.

When to Use

• User wants to run a modded Minecraft server locally or on a VPS
• User wants to install a CurseForge or Modrinth modpack on a server
• User wants to configure server memory and JVM flags
• User wants to automate server startup with a batch script
• User wants to manage mods — add, remove, or update individual mods

How to Use

1. Prerequisites

# Verify Java 21+ is installed (required for 1.20.x+)
java -version
# Install from: https://adoptium.net/temurin/releases/?version=21

# Create server directory
New-Item -ItemType Directory -Path "C:\mc-server" -Force
Set-Location "C:\mc-server"

2. Install NeoForge server

# Download NeoForge installer from https://neoforged.net/
# Get the installer for your Minecraft version
$neoforgeVersion = "21.1.99"   # replace with desired version
$installerUrl    = "https://maven.neoforged.net/releases/net/neoforged/neoforge/$neoforgeVersion/neoforge-$neoforgeVersion-installer.jar"
Invoke-WebRequest -Uri $installerUrl -OutFile "neoforge-installer.jar"

# Run installer (creates server files)
java -jar neoforge-installer.jar --installServer

3. Accept the EULA

# Required before server will start
Set-Content -Path "eula.txt" -Value "eula=true"

4. Create an optimized startup script

# start.bat — save in C:\mc-server\
$startBat = @'
@echo off
java -Xmx6G -Xms2G ^
  -XX:+UseG1GC ^
  -XX:+ParallelRefProcEnabled ^
  -XX:MaxGCPauseMillis=200 ^
  -XX:G1HeapRegionSize=16M ^
  -XX:G1ReservePercent=25 ^
  -jar libraries/net/neoforged/neoforge/21.1.99/neoforge-21.1.99-server.jar ^
  nogui
pause
'@
Set-Content -Path "C:\mc-server\start.bat" -Value $startBat

Adjust -Xmx (max RAM) and -Xms (initial RAM) based on available system memory.

5. Add mods to the server

# Mods go in the mods/ directory
New-Item -ItemType Directory -Force -Path "C:\mc-server\mods"

# Download a mod from Modrinth (example: Fabric API replacement for NeoForge)
$modUrl = "https://cdn.modrinth.com/data/AANobbMI/versions/xxxxx/mod-name.jar"
Invoke-WebRequest -Uri $modUrl -OutFile "C:\mc-server\mods\mod-name.jar"

# List installed mods
Get-ChildItem "C:\mc-server\mods" -Filter "*.jar" | Select-Object Name, Length

6. Install a CurseForge modpack

# 1. Download the server pack ZIP from CurseForge (not the client pack)
# 2. Extract to server directory
Expand-Archive -Path "modpack-server.zip" -DestinationPath "C:\mc-server" -Force

# 3. Run the modpack's install script (varies by pack)
Set-Location "C:\mc-server"
.\startserver.sh   # or start.bat depending on the pack

7. Configure server.properties

# Key settings in server.properties
$config = @"
max-players=10
difficulty=normal
spawn-protection=0
view-distance=10
online-mode=true
motd=My Modded Server
"@
Add-Content -Path "C:\mc-server\server.properties" -Value $config

8. Start the server

Set-Location "C:\mc-server"
.\start.bat

Examples

"Set up a NeoForge 1.21.1 server with 8GB RAM" → Use steps 1–4. Adjust -Xmx8G in the startup script.

"Add the Create mod to my existing server" → Use step 5 — download the Create jar for NeoForge from Modrinth and place in mods/.

"Install the All The Mods 9 server pack" → Use step 6 — download the ATM9 server pack ZIP from CurseForge and extract with step 6.

Cautions

• Always use the NeoForge/Forge version that matches your target Minecraft version exactly
• Client mods (rendering, shaders, HUD) must NOT be placed on the server — server-side only mods apply
• Increase -Xmx proportional to mod count — large packs (200+ mods) need at least 8-12GB
• online-mode=true requires all players to have a paid Minecraft account (prevents cracked clients)
• Back up the world/ directory regularly — server crashes can corrupt world data