️ AntiDupe – Protect Your Server From Dupers (FREE)
Keep your Minecraft economy fair and your players honest with AntiDupe — the ultimate lightweight dupe prevention system.
Designed to automatically detect, block, and log duplication exploits before they can harm your world.

⚔️ Key Features

• Dupe Detection – Instantly detects suspicious inventory or entity-based item increases.
  
  
• ⏱️ Timing Protection – Monitors rapid clicks and inventory actions to stop click-based dupes.
  
  
• Entity Protection – Prevents killing or exploiting storage entities (like llamas, mules, or minecart chests) with items inside.
  
  
• Smart Tracking – Takes snapshots of player inventories and compares them for unexpected item growth.
  
  
• Bypass Permissions – Give trusted players or admins immunity with simple permissions.
  
  
• ⚙️ Configurable Modules – Fully customizable through config.yml. Enable or disable any system.
  
  
• Player Alerts – Sends clear, color-coded warnings to violators and logs all suspicious actions.

⚙️ Permissions
Permission Description
antidupe.bypass Exempts players from dupe checks
antidupe.alerts Allows players to see alerts
antidupe.reload Allows players to reload the plugin
antidupe.admin Allows access to admin-only AntiDupe commands
Configuration
AntiDupe’s config.yml is simple and clean — toggle modules like:

# AntiDupe Configuration - Advanced Anti-Duplication System

# General Settings
settings:
# Enable debug logging
debug: false

# Enable alerting staff of potential dupes
alerts: true

# Punishment for duping attempts
punishment:
enabled: true
type: 'BAN' # Options: BAN, KICK, WARN
duration: -1 # -1 for permanent, or time in minutes

# Auto-rollback on dupe detection
rollback:
enabled: true
# Restore inventory state from before dupe attempt
restore-inventory: true

# Detection Modules
modules:
# Inventory dupe detection (shift-click, drop, etc)
inventory-dupe:
enabled: true
# Check for duplicate item stacks appearing
check-duplicates: true
# Maximum allowed identical stacks per inventory check
max-identical-stacks: 5
# Track item amounts
track-amounts: true

# Anvil dupe exploits
anvil-dupe:
enabled: true
# Prevent taking items while anvil is processing
prevent-early-take: true
# Track anvil transactions
track-transactions: true

# Hopper dupe exploits
hopper-dupe:
enabled: true
# Check for items being duplicated via hoppers
check-item-transfer: true
# Maximum hopper chain length to check
max-chain-length: 10

# Chunk dupe (unloading chunks with items)
chunk-dupe:
enabled: true
# Prevent dropping items near chunk borders
prevent-border-drops: true
# Border distance in blocks
border-distance: 3

# Donkey/Llama chest dupes
entity-storage-dupe:
enabled: true
# Track items in entity inventories
track-entity-inventories: true
# Prevent killing entities with items
prevent-kill-with-items: false

# Death dupe (combat logging, etc)
death-dupe:
enabled: true
# Check inventory before/after death
check-death-inventory: true
# Prevent logging out during combat
combat-log-check: true
combat-tag-time: 15 # seconds

# Creative mode dupes
creative-dupe:
enabled: true
# Prevent creative players from dropping items
prevent-creative-drops: true
# Log creative item spawning
log-creative-spawns: true

# Book & Quill dupe exploits
book-dupe:
enabled: true
# Track book signing operations
track-book-signing: true

# Chest minecart dupes
minecart-dupe:
enabled: true
# Track minecart inventory changes
track-minecart-inventory: true

# Packet-based dupes
packet-dupe:
enabled: true
# Check for invalid packet sequences
check-invalid-sequences: true
# Maximum packet rate per second
max-packet-rate: 50

# Timing-based dupes
timing-dupe:
enabled: true
# Check for suspiciously fast actions
check-action-speed: true
# Minimum time between actions (ms)
min-action-time: 50

# Item Tracking
tracking:
# Enable item tracking system
enabled: true

# Track these item types (empty = all)
tracked-items:
- 'DIAMOND'
- 'DIAMOND_BLOCK'
- 'EMERALD'
- 'EMERALD_BLOCK'
- 'GOLD_INGOT'
- 'GOLD_BLOCK'
- 'IRON_INGOT'
- 'IRON_BLOCK'
- 'ENCHANTED_BOOK'

# Minimum stack size to track (0 = track all)
min-stack-size: 1

# Store tracking data in database
database:
enabled: true
# How long to keep tracking data (days)
retention-days: 30

# Detection Thresholds
thresholds:
# Violation points before action
violation-points: 10

# Points decay over time
decay:
enabled: true
# Points removed per minute
points-per-minute: 1

# Instant ban thresholds
instant-ban:
enabled: true
# Ban if this many identical items appear instantly
item-threshold: 1000

# Logging
logging:
# Log to file
file: true

# Log to console
console: true

# Log all checks (very verbose)
log-all-checks: false

# Log only violations
log-violations: true

# Log player actions
log-actions: true

# Messages
messages:
prefix: '&c&l[AntiDupe]'

violation-detected: '%prefix% &7Potential dupe detected from &e%player%&7! Type: &c%type%'

player-punished: '%prefix% &e%player% &7has been &c%punishment% &7for duping!'

inventory-restored: '%prefix% &7Your inventory has been restored.'

bypass-enabled: '%prefix% &7You have bypass mode enabled.'

stats-header: '%prefix% &e&lAntiDupe Statistics'
stats-violations: '&7Total Violations: &c%violations%'
stats-prevented: '&7Dupes Prevented: &a%prevented%'
stats-players: '&7Flagged Players: &e%players%'

reload-success: '%prefix% &aConfiguration reloaded successfully!'

no-permission: '%prefix% &cYou do not have permission to use this command!'

alerts-enabled: '%prefix% &aAlerts enabled!'
alerts-disabled: '%prefix% &cAlerts disabled!'

Why Choose AntiDupe?
✅ Lightweight — won’t affect server performance.
✅ Free forever — no paywalls or hidden features.
✅ Constantly updated to block new dupe exploits.
✅ Has violation logs and stored data so you can see who duped.
✅ Works on 1.8.8 → 1.21+ with full compatibility.