Better Anti Dupe

Minecraft 1.21.x: the plain jar.
Minecraft 26.x: the jar ending in -mc26.

More info? Read about it in the docs

One of the oldest dupes in the game.
All it needs is a piston and a rail or carpet.
With Better Anti-Dupe, these dupe-machines are disabled by default.

More info? Read about it in the docs

TNT dupers power world eaters and flying machines.
They stop working from day one.
Running an anarchy or tech server? One switch turns them back on.

More info? Read about it in the docs

Sand and gravel can no longer be copied through a portal.
Farms and flying machines that push sand keep working.

More info? Read about it in the docs

A player can't keep taking items from a chest that's already gone.
The window simply closes.
Nobody playing normally will ever notice.

More info? Read about it in the docs

No machine needed, just good timing during a restart.
Every open window closes as the server shuts down.
Nothing is left to copy.

More info? Read about it in the docs

The heart of the plugin.
It knows what each player earned, and counts what they hold.
Shulker boxes and bundles included. Holding more? You'll know.

More info? Read about it in the docs

Every dropped item is one of a kind.
If the same one is picked up twice, it was copied.
This is the most certain alert there is.

More info? Read about it in the docs

Breaking a block or a frame drops a known amount.
Picking up more than that nearby means something was copied.

More info? Read about it in the docs

Dupe a few items, hide them in a chest, and hope nobody notices.
It's an old trick.
Small amounts are remembered for a day, and they add up to an alert.

More info? Read about it in the docs

Some dupes never touch a player's inventory.
The copies simply appear in a chest.
You're told whose items they were, who took them, and where.

More info? Read about it in the docs

Dupers pass items through hoppers to make them look clean.
The route is written down, so you can follow it.
Or block hoppers from moving watched items at all.

More info? Read about it in the docs

You decide how many of an item anyone could honestly get in a minute.
Going past it makes a player worth a closer look.

More info? Read about it in the docs

Duping usually happens alone.
A player whose gains nobody ever sees becomes a little more suspicious.
It never accuses anyone on its own.

More info? Read about it in the docs

Every record is sealed to the one before it.
Even an admin can't quietly change history.
One command shows exactly where it was touched.

More info? Read about it in the docs

Knowing someone duped is only half the job.
One command lists where they put the items.
Click the coordinates and you're there, even in another world.

More info? Read about it in the docs

Every alert has [History] and [Stash] buttons.
Look, decide, done.
Confirm a duper, clear a false alarm, or take the extras back.

More info? Read about it in the docs

You don't have to be online to know.
Discord, Telegram, Slack, or your own webhook.
Only the serious alerts, and no spam. One command tests your setup.

More info? Read about it in the docs

Nothing is taken from anyone until you say so.
Watch the alerts for a while. Once you trust them, turn on automatic removal.
It only ever takes the extras, never a whole stack.

More info? Read about it in the docs

Your players won't notice a thing.
Watched items stack and trade like any other item.

More info? Read about it in the docs

Mods that show hidden item data see nothing.
A duper testing on two accounts can't tell which items are watched.

More info? Read about it in the docs

English, Português do Brasil, Español, Deutsch, Русский and Polski are built in.
Every message can be changed to your liking.

More info? Read about it in the docs

Items travel between servers on a network.
Share records through Redis, and a dupe on one server is spotted on another.

More info? Read about it in the docs

Almost nobody opens a ticket, so I cannot tell which Minecraft versions run it.
Knowing that helps me fight dupes on those versions first.

• Sent: your settings, versions, and counts of dupes caught, removed and blocked.
• Never sent: addresses, server names, player names, or anything from your records.
• Kept private. Public numbers would help dupers pick unprotected servers.
• Error reports are cleaned of passwords, tokens and ids before they leave your server.

Set metrics.enabled: false to send nothing at all.
Nothing is ever shared, sold, or made public.

More info? Read about it in the docs