IG: Stack Size Adjuster

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📦 Stack Size Adjuster

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

📖 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.

✨ 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.

📊 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 |

⚙️ 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. |

📖 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!