Core Extension

What Is the Core Extension?

The out-of-the-box backpack experience built on top of the MCBackpack provider API.
Delivers the /bp command (alias /backpack), backpack items, secure password prompts, and item customization.
Runs on PaperMC, SpigotMC, and FoliaMC.

Loaded by MCBackpack: the extension manager discovers the Core-*.jar in plugins/MCBackpack/extensions/libs and loads it at startup or on reload.
Registers dynamically: Core registers the /bp command and its inventory listeners at runtime — no plugin.yml entry required.
Players use backpacks: they create backpack items, open them, and lock them with passwords entered securely through chat.
Provider persists: contents are serialized and saved through the MCBackpack provider, landing in whichever database backend the server configured.

Backpack creation: customizable backpack items with a configurable size (multiples of 9, from 9 to 54 slots) and custom head textures.
Password protection: backpacks lock with PBKDF2/SHA-256 hashed passwords, entered through secure chat prompts and never shown to others.
Texture and model applicators: special items that re-skin an existing backpack with a new head texture or apply custom model data for resource packs.
Safety built in: recursive storage prevention stops backpacks from nesting inside each other, and a reopen cooldown prevents spam while data is persisting.

bukkit — shared, platform-independent backpack domain logic: commands, listeners, managers, and the tab completer.
platforms — dedicated Core entry points for PaperMC, SpigotMC, and FoliaMC, each built into its own extension jar.
extension.yml — the extension descriptor consumed by the MCExtension loader to identify and wire up the Core extension.

Requirement

Core is not a standalone plugin.

It requires the MCBackpack plugin to be installed on the server first, and talks to backpack storage exclusively through the provider API.

How the framework hosts providers, databases, and the extension system that powers Core.

The Core extension repository.

The MCEngine ecosystem homepage.