ItemizerX 3

ItemizerX is a Paper plugin for editing items in game. Version 3 targets Minecraft 26.1 through 26.2 (including 26.1.1 and 26.1.2) and requires Java 25.

What changed in 3.0

• Removed all versioned NMS/CraftBukkit code and the paperweight/reobfuscation build.
• Converted the project to a native Paper plugin and registered /itemizer through Paper's Brigadier lifecycle API instead of Bukkit's legacy command executor.
• Attributes and enchantments are read from the running server's registries, so new vanilla and datapack-provided entries appear automatically.
• Attribute modifiers support all three operations, every current equipment slot group, and custom namespaced modifier keys.
• Added direct vanilla item-component input using Paper's ItemFactory#createItemStack API.
• Added convenient editors for item metadata such as max stack size, max damage, glider, rarity, enchantability, item model, tooltip style, and enchantment glint override.
• Added structured editors for food, consumable, equippable, cooldown, attack-range, and tool components.
• Added bounded delta-based undo/redo, typed persistent data, item presets, bundle/container editing, a native Dialog API editor, and an inventory fallback.
• Updated Paper, CoreProtect, bStats, Gradle plugins, the Gradle wrapper, and the Java toolchain.

New commands

/itemizer amount <1-99>
/itemizer component show
/itemizer component nbt
/itemizer component apply <[component=value,...]>
/itemizer component replace <minecraft:item[component=value,...]>
/itemizer component reset
/itemizer component food <nutrition> <saturation> [always-eat]
/itemizer component consumable <seconds> <animation> [particles] [sound]
/itemizer component equippable <slot> [swappable] [dispensable] [damage-on-hurt]
/itemizer component cooldown <seconds> [group]
/itemizer component attack-range <min> <max> [creative-min] [creative-max] [margin] [mob-factor]
/itemizer component tool <default-speed> <damage-per-block> [creative-destroy]
/itemizer property list
/itemizer property <property> <value|reset>

/itemizer attr add <attribute> <amount> [operation] [slot-group] [modifier-key]
/itemizer attr edit <attribute> <amount> [operation] [slot-group] [modifier-key]
/itemizer attr remove <attribute> [modifier-key]
/itemizer attr list
/itemizer attr listall

/itemizer undo
/itemizer redo
/itemizer data list|get|set|remove
/itemizer container list|add|remove|clear
/itemizer preset list|save|load|delete|export|import
/itemizer gui
/itemizer inventory

Attribute operations are add_number, add_scalar, and multiply_scalar_1. Slot groups are any, mainhand, offhand, hand, feet, legs, chest, head, armor, body, and saddle.

component apply accepts the component portion of vanilla /give syntax. component replace accepts the complete item argument. These commands expose new data components without requiring an ItemizerX release for each component Mojang adds.

Vanilla registry completions omit the redundant minecraft: namespace, so commands such as /itemizer attr edit scale ... can use and complete the short key. Non-vanilla namespaces remain fully qualified.

Safety limits

• Undo history stores reversible component-string deltas rather than full item snapshots. It is limited to 50 entries and 256 KiB per player, with a 32 KiB maximum individual delta.
• Undo and redo verify a SHA-256 state fingerprint and refuse to modify a different held item.
• Presets are limited to 32 per player and 2,048 server-wide. Import tokens are size-limited, validated by Minecraft's item parser, rate-limited, and saved in a debounced batch.
• Persistent data values are limited to 4,096 characters. Players may only write to the itemizerx namespace unless explicitly granted itemizer.data.foreign.
• Raw component input and chat output are size-limited. The editor inventory cancels all movement, drag, hotbar, and creative click paths while it is open.
• Dialog submissions are tied to a five-minute, single-player session and a fingerprint of the previewed held item; changing items before applying causes the edit to be refused.
• Container add copies the off-hand item as an intentional administrative edit; it never consumes or moves inventory contents, which keeps undo/redo isolated to the held item.

Build

.\gradlew.bat clean build

The same sources can be checked against the oldest published supported API with:

.\gradlew.bat clean build "-PpaperApiVersion=26.1.1.build.29-alpha"

The deployable jar is build/libs/ItemizerX-3.0.0.jar. Development server tasks are available as runServer-26.1.1, runServer-26.1.2, and runServer-26.2 (Paper did not publish a downloadable 26.1 server build).