AlleviatedBackpacks

Backpacks with upgrades for Minecraft Bedrock Edition, as a LeviLamina mod. It brings the gameplay of the Java mod Sophisticated Backpacks to Bedrock and works on dedicated servers (BDS) and in single-player / local worlds on the client.

• Minecraft 1.26.51, LeviLamina 26.51.7, Windows x64.
• Players need the client mod (the client build, download): it draws Sophisticated Backpacks' own screens (storage with scroll bar and search, upgrade column with switches, upgrade tabs, settings screen), adds the key bindings and the Shift contents tooltip. Every item move is still done by the server. A player without the client mod can join and carry backpacks (upgrades keep working), but opening a backpack screen shows "AlleviatedBackpacks needs its client mod" with the download link.

Features

• Six backpack tiers (backpacks never stack):

  Tier	Storage slots	Upgrade slots
  Leather	27	1
  Copper	45	1
  Iron	54	2
  Gold	81	3
  Diamond	108	5
  Netherite	120	7

• Right-click a backpack (or press B) to open it: Sophisticated Backpacks' screen — 9 or 12 columns, a scroll bar when the rows don't fit, the upgrade column with on/off switches, upgrade tabs on the right, the search box (@mod, #tooltip, name), sort / sort-by and transfer buttons, abbreviated counts for large stacks, memory and no-sort slots. The settings tab opens the backpack settings screen (memory, no-sort, context and main options).

• Key bindings (Settings > Keyboard & Mouse): Open Backpack B (also over a backpack in any inventory, and over a nested backpack), Inventory Interaction C (Deposit / Restock on the container you look at), Tool Swap (unbound), Toggle Upgrade 1/2 Alt+Z / Alt+X (3-5 unbound), Sort (middle mouse), Transfer to Storage / Inventory [ / ] (Shift: everything).

• Shift over a backpack item shows its contents: stack multiplier, tanks, upgrades with their on/off state and the items, most first.

• Contents belong to the backpack, not to the player: drop it, give it away, put it in a chest — the items stay inside. Data is stored in the world itself, so it moves with the world folder.

• Upgrades go into the backpack's upgrade slots and can be switched on and off individually; most have their own settings tab with item filters (allow/block list, match by item, namespace or tag, NBT and durability options). Every Sophisticated Backpacks upgrade is there, basic and advanced: Pickup, Filter, Magnet, Feeding, Compacting, Void, Restock, Deposit, Refill, Tool Swapper, Jukebox, Pump, Alchemy, Mob Catcher; Stack (Starter, Tier 1-4, Omega, downgrades and conversion items); Crafting, Stonecutter, Anvil, Smithing; Smelting, Smoking, Blasting and their Auto versions; Inception, Everlasting, Infinity, Survival Infinity; Tank, Battery, XP Pump. Only the Chipped and Sawmill compat upgrades are missing, because those mods are Java-only.

  • Bedrock has no Forge Energy or fluid handlers, so AlleviatedBackpacks provides both as a small public API (FE and mB) that the Tank, Battery, Pump and XP Pump upgrades use. Other mods can use it too: see docs/API.md.

• Feature-by-feature comparison with Sophisticated Backpacks: docs/FEATURES.md.

• Backpacks can't be put into themselves, and by default not into other backpacks (an Inception upgrade allows it). Like Sophisticated Backpacks, shulker boxes fit in backpacks (containerItemsDisallowed refuses them) and backpacks don't fit in shulker boxes or bundles (canBePlacedInContainerItems).

• World systems as in Sophisticated Backpacks: the Ender Linker links backpacks into a linked storage group with shared contents; duplicated backpacks (same storage) are sorted out; right-click another player's back to open their worn backpack; mobs sometimes spawn wearing filled backpacks; dungeon and other loot chests sometimes hold backpacks and upgrades.

• English and Simplified Chinese; the GUI follows each player's language.

Commands (alias /abp):

Install

There are two builds from the same source: server (for BDS) and client (for the game). Every player needs the client build, both on a server and in single player. Use the same version on the server and on the clients.

With lip:

lip install github.com/LiteLDev/AlleviatedBackpacks          # in the BDS folder (server build)
lip install github.com/LiteLDev/AlleviatedBackpacks#client   # in the game folder (client build)

Manually: download alleviatedbackpacks-server-windows-x64.zip or alleviatedbackpacks-client-windows-x64.zip from the latest release and follow the steps below.

Dedicated server (BDS + LeviLamina)

1. Install LeviLamina 26.51.7 for the server (lip install github.com/LiteLDev/LeviLamina@26.51.7).
2. Download the server build (or build it, see below) and extract it so that the folder AlleviatedBackpacks/ ends up in the server's plugins/ folder.
3. Start the server. On first start the mod adds its resource pack to worlds/<level-name>/world_resource_packs.json and asks clients to download it. The behavior pack (items and recipes) is loaded automatically.
4. Tell your players to install the client mod (next section), then join the server as usual. Players without it can still join and carry backpacks, but can't open backpack screens.

Players: the client mod (LeviLauncher), for servers and single player

1. In LeviLauncher, install the 1.26.51 game version with LeviLamina 26.51.7.
2. Download the client build and extract it so that its AlleviatedBackpacks/ folder ends up in %APPDATA%\levilauncher.exe\versions\<version>\mods\ (for example versions\1.26.51.01\mods\).
3. Start the game.
   • Single player: every local world gets the backpacks, recipes and upgrades. No world settings need changing; the mod brings its own behavior and resource packs.
   • Multiplayer: join a BDS running the server build. Use the same mod version on both.
4. The key bindings are under Settings > Keyboard & Mouse (see Features).

Configuration

AlleviatedBackpacks/config/general.json (created on first start):

Sophisticated Backpacks' own settings, with SB's names, defaults and ranges: config/sophisticatedbackpacks-server.json (disallowed items, slot counts per tier, entity backpack additions, nerfs, max upgrades per storage, other-player opening, dedup, ...), config/sophisticatedbackpacks-common.json (chestLootEnabled) and config/sophisticatedcore-common.json (enabledItems). Upgrades add their own config/<upgrade>.json files with SB's sections for that upgrade (for example refill.json: refillUpgrade.filterSlots); config/admin.json and config/wearable.json hold AlleviatedBackpacks extras that are off by default.

Building

Requirements: Windows x64, xmake, Visual Studio 2022+ build tools, LLVM (clang-cl), git with core.longpaths enabled.

pwsh tools/build.ps1 -Target all -Tests

Outputs: bin/server/AlleviatedBackpacks/ and bin/client/AlleviatedBackpacks/.

AGENTS.md describes the architecture, the conventions and the rules for working with Bedrock internals. tools/e2e holds the end-to-end test harnesses that drive the real server and game.

Maintainers

@futrime (Zijian Zhang)

Contributing

PRs and issues are welcome. Please read CONTRIBUTING.md and follow the Code of Conduct. Report security issues as described in SECURITY.md. Changes are listed in CHANGELOG.md.

Credits

Inspired by Sophisticated Backpacks by P3pp3rF1y. This is an independent implementation for Bedrock; no code or assets are taken from the original mod.

License

LGPL-3.0 © 2026 Zijian Zhang

AlleviatedBackpacks is free software: you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License version 3, the same license as LeviLamina. See COPYING.LESSER and COPYING.

AlleviatedBackpacks is not affiliated with Mojang Studios, Microsoft, or the Sophisticated Backpacks project.