📦 Stack Size Adjuster

"Unshackle Your Inventory. Custom Stack Sizes Up to 9,999 with 100% Network Safety."

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📖 Introduction

Minecraft's universal 64-item stack size ceiling was decided over 15 years ago when the game had a fraction of today's blocks, items, and crafting complexity. In modern survival, undertaking large-scale builds—such as castles, nether highways, terraformed mountains, or automated storage warehouses—demands endless tedious chest-sorting, dozens of shulker boxes, and constant back-and-forth hauling trips for simple building materials like Cobblestone, Dirt, Sand, and Logs.

Stack Size Adjuster solves the inventory crisis under the Instant Gratification design philosophy. It dynamically expands item stack limits server-wide up to 9,999 items (or custom limits). Leveraging modern Minecraft's VarInt network protocol, mega-stacks synchronize seamlessly between server and client with zero desynchronization, full container safety, hopper protection, and trade GUI safeguards.

[!NOTE] 1 Jar 1 Version Policy: I build 1 dedicated JAR for each Minecraft version (e.g. MC 26.2, MC 26.3). Please download the exact build that matches your Minecraft installation.

Server-Authoritative: Requires installation on the server. Clients running Fabric will natively display accurate custom stack counts in inventories, while vanilla clients receive synchronized VarInt stack updates!

Part of the Instant Gratification Collection — mods that respect the player's time.

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✨ Features

🚀 Massive Stack Expansion (Up to 9,999)

• Universal or Category Limits: Expand maximum stack limits for building blocks, ores, food, and raw materials from 64 up to 9,999 items per inventory slot.
• Modern VarInt Network Protocol: Built from the ground up for modern Minecraft (26.x+), utilizing VarInt network serialization rather than legacy 1-byte limits. Mega-stacks serialize effortlessly across multiplayer packets with zero data truncation.

🛡️ Container & Trade Menu Safeguards

• Hopper Drip-Feed Throttling: Hoppers and droppers under mega-stacks transfer exactly 1 item per standard vanilla transfer tick, ensuring sorting systems, item elevators, and redstone contraptions never overflow or stall.
• Villager & Merchant Protection: Prevents trading exploits and inventory overflow when interacting with Wandering Traders and Villagers by dynamically clamping exchange slots to safe standard limits.
• Crafting Grid Precision: Shift-clicking crafted items smoothly fills available mega-stacks without scattering leftover items onto the floor.

⚙️ Modular Whitelist & Blacklist Tag Engine

• Item Exclusions: Keep specific delicate items unstackable (e.g. Shulker Boxes containing items, Enchanted Books, or custom modded containers) using data-driven tags (#stack_size_adjuster:unstackable_blacklist).
• Targeted Category Overrides: Assign custom stack thresholds to specific item categories—for example, 1,000 for raw building materials, 256 for food, and 16 for tools.

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📊 Inventory Capacity Comparison

Storage Container	Vanilla 64-Cap Limit	With 256 Stack Limit	With 1,000 Stack Limit	With 9,999 Mega-Stacks
Player Main Inventory (27 slots)	1,728 items	6,912 items	27,000 items	269,973 items
Single Chest (27 slots)	1,728 items	6,912 items	27,000 items	269,973 items
Double Chest (54 slots)	3,456 items	13,824 items	54,000 items	539,946 items
Shulker Box (27 slots)	1,728 items	6,912 items	27,000 items	269,973 items
Ender Chest Capacity	1,728 items	6,912 items	27,000 items	269,973 items

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⚙️ Native GameRules & Configuration

Configure stack size limits dynamically on the fly:

GameRule Key	Type	Default	Valid Range	Description
stack_size_adjuster:max_stack_size	Integer	1000	64 – 9999	Global maximum stack limit for configured item categories.
stack_size_adjuster:affect_blocks_only	Boolean	false	true / false	Restricts stack increases strictly to placeable block items.
stack_size_adjuster:enable_food_stacking	Boolean	true	true / false	Extends mega-stacking to edible food items.
stack_size_adjuster:protect_shulker_boxes	Boolean	true	true / false	Prevents nesting filled shulker boxes inside mega-stacks.

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📖 In-Depth How-To & Gameplay Playbook

Step 1: Server & Client Installation

1. Install Fabric Loader and Fabric API for Minecraft 26.2+ / 26.3+.
2. Drop stack-size-adjuster-x.y.z+<version>.jar into your server and client mods/ folders.
3. Launch Minecraft. Building blocks will now automatically stack up to the configured limit!

Step 2: Consolidating Storage Warehouses

• Walk into your warehouse and shift-click matching items together: watch entire double chests of cobblestone condense into just a few slots.
• Free up hundreds of chests, dramatically reducing entity and tile-entity rendering lag in your main survival base!

Step 3: Pairing with Companion Addons

• For stacking drinkable and splash potions, install Potion Stacker Addon.
• For stacking mushroom stews, rabbit soups, and suspicious stews, install Stew Stacker Addon.
• For ground-item lag cleanup, install Item Clumps!

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☕ Support & Creator Community

I am an independent solo developer creating lightweight, vanilla-enhancing mods that respect your time and game performance. If Stack Size Adjuster liberates your inventory, consider supporting future development:

[!TIP] 🇮🇩 Indonesian Local Payment Note: Indonesian supporters can also support my development work directly using local payment options (GoPay, OVO, Dana, QRIS, LinkAja) via Saweria or SocioBuzz!

Join our official Discord community for live development updates, early test builds, and friendly support:

• 💬 Discord Community: https://discord.gg/EV99bgAFqb

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📜 Metadata & Permissions

Property	Value
Mod Name	Stack Size Adjuster
Namespace / Mod ID	stack_size_adjuster
License	GNU General Public License v3.0 (GPLv3)
Side Safety	Server & Client (Network Synchronized)
Source Code	GitHub Repository
Issue Tracker	GitHub Issues

[!IMPORTANT] 📦 Modpack Permissions & Distribution:
You are fully welcome to include this mod in any modpack on any platform! However, the mod file must be downloaded directly through official distribution channels (Modrinth or CurseForge). Re-uploading, mirroring, or redistributing the original mod JAR to third-party mirror sites, scraper portals, or unauthorized launchers is strictly prohibited.

⚖️ License & Fork Guidelines (No Zero-Change Re-uploads):
This project is open-source under the GNU GPLv3. You are fully encouraged to inspect the code, learn from it, and fork the repository to create genuine modifications, substantial feature expansions, or community ports—provided your project remains open-source under GPLv3 with proper attribution.
However, straight 1:1 re-uploads, clone forks with no meaningful functional changes, or re-publishing identical builds under different project names (e.g. to farm downloads or rewards) are strictly forbidden.

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