Test Your Mod Before Your Players See It

Every mod that goes straight onto a live server eventually costs you a world backup or an evening of angry players. Testing takes ten minutes. Here's where to do it and what to actually check.

#Plugins: launch a test server from Creator Hub

For a completed server-only Paper or Spigot build, the project page has a Launch server button. Click it and you get a real server with your plugin already installed.

• It boots with your plugin installed and runs for 30 minutes after it's ready.
• Up to five players can join with the address it shows you.
• You see the live console and can type server commands into it.
• Launching doesn't use credits.

It's available on accounts with a completed credit purchase or an active Warp subscription. The server runs Paper, which handles both Paper and Spigot plugins.

Invite one friend. A second player finds things you can't see alone: what they see in chat, whether your command affects them, what happens when two people run it at once.

#Mods: test in a throwaway instance

Client and Both mods run on your computer, so test them there, but not on the install you play on.

• Loom, our Windows desktop app, keeps separate instances. Make one per mod, drop the JAR in, play, delete it when you're done. Get Loom.
• Or make a second launcher profile with its own game directory.
• Always use a new world. Never load your main save with an untested mod.

For a Both mod on a server, install it on a test server and on your test client at the same time. Install a mod on your computer covers the client side.

#What to actually test

First, the thing you asked for. Then the ways it could go wrong.

Anything that breaks under that list is a follow-up message, and you now have the exact steps to describe it. What to say when the first build isn't right shows the format.

#Before it goes live

• Back up the world. Every host has a backup button. Use it.
• Announce it. Tell players what's new and what command to try.
• Keep the old JAR so you can roll back in one restart.
• Watch the console for the first few minutes after restart. Errors show up fast when real players hit the mod.