Pufferfish's Skills - MT Inventory Weight Add-On Guide

Connect skill progression to inventory weight with Pufferfish's Skills - MT Inventory Weight for Minecraft. Boost capacity via attributes and events.

Pufferfish's Skills - MT Inventory Weight

Carrying capacity is one of the most persistent frustrations in Minecraft. You mine a few stacks of ore, and suddenly you are waddling back to base at a snail's pace. While many mods offer simple backpack upgrades or static weight increases, Pufferfish's Skills - MT Inventory Weight takes a different approach: it ties your maximum inventory weight directly to your character's skill progression. This server-side add-on bridges two powerful mods, MT Inventory Weight and Pufferfish's Skills, to create a dynamic and rewarding progression loop.

Instead of a flat bonus, this add-on lets you earn the right to carry more. As your skills grow, so does your capacity. Whether you are a solo player on an integrated server or an admin running a dedicated server, this tool offers flexible, data-driven ways to scale weight limits. Let's break down exactly how it works, how to configure it, and how to install it.

How the Integration Works

The core idea is simple: Pufferfish's Skills is server-authoritative for skill levels, and this add-on runs entirely on the server side. It works for both single-player worlds (including Open to LAN) and dedicated servers. It connects to MT Inventory Weight's registered vanilla-style attribute, inventoryweight:generic.max_weight, and modifies it based on your skill data.

There are two primary methods for this connection, each suited for different use cases. You can use one, the other, or both simultaneously, as the bonuses stack.

1. Attribute Reward (Data-Driven)

This method requires no Java coding. It leverages Pufferfish's Skills' built-in puffish_skills:attribute reward type. In a skill category's definitions.json, you simply point a reward at the inventory weight attribute. For example, a skill node can grant a flat bonus:

{
  "type": "puffish_skills:attribute",
  "data": {
    "attribute": "inventoryweight:generic.max_weight",
    "value": 200.0,
    "operation": "addition"
  }
}

This is the recommended approach for modpack developers. The addition operation adds a flat value, which is the most predictable. You can also use multiply_base or multiply_total, but if the base attribute is zero, those operations may have little effect. The bundled "Carrying" skill tree uses this method.

2. Java Event Connector (Level-Based Scaling)

For dynamic scaling, the add-on listens to MT Inventory Weight's MODIFY_MAX_WEIGHT event. It reads a specific skill category's experience level via the Pufferfish's Skills API and applies a configurable formula to the final weight. This allows for continuous growth as you level up, rather than static node bonuses.

The Built-in "Carrying" Skill Tree

To help you get started immediately, the mod ships with an optional, built-in skill tree called "Carrying." This is registered as a Fabric built-in datapack, meaning it appears in the world-creation Data Packs screen but is disabled by default. It grants flat and percentage-based weight increases, plus a small movement-speed node and a capstone for high-level players. You gain experience for this tree by mining blocks and crafting items.

To enable it in a new world, go to Create World, then Data Packs, and move "Carrying Skill Tree" to the active side. For existing worlds, use the commands /datapack list and then /datapack enable "<id>". Once active, press the default key K to open the skills screen and see the new category.

Customizing for Modpacks

You are not locked into the default tree. Modpack developers and server admins have three options:

  • Use the default: Just enable the built-in pack. No extra files needed.
  • Override it: Ship a datapack that redefines the carrying category under the puffish_skills namespace. A later-loaded pack overrides the built-in files.
  • Add a separate tree: Define a new category with a different ID and your own namespace. This is the cleanest method, as it avoids conflicts with the built-in pack.

Configuration and Formulas

The Java event path uses a synced server config via fzzy_config, located at config/pufferfishs-skills-inventoryweight/server-config.*. The main options include a master switch and a floor for the final weight. You can scale by a single category or by the total of all categories.

For category-based scaling, you define the category ID and per-level bonuses. The formula is:

result = (currentMaxWeight + additive) * multiplier
result = max(minimumMaxWeight, result)

For example, if your base max weight is 100, your adventure category level is 10, and the multiplier per level is 0.05, the multiplier becomes 1.5, resulting in a final weight of 150. This stacks with MT Inventory Weight's base config and other add-ons.

Installation and Dependencies

Before you can download Pufferfish's Skills - MT Inventory Weight, you need to ensure you have the required dependencies. This mod is not standalone. You will need:

  • MT Inventory Weight (provides the API)
  • Pufferfish's Skills (puffish_skills)
  • fzzy_config (for configuration)
  • Fabric API and Fabric Loader

This add-on supports the latest stable Minecraft versions for Fabric. For a hassle-free experience, consider using the foxygame.net launcher. It offers a one-click install feature that automatically resolves dependencies and manages version compatibility for Pufferfish's Skills - MT Inventory Weight for Minecraft, ensuring you spend less time troubleshooting and more time playing. The launcher's add-on catalog also helps you discover related mods and updates.

How to Install

To understand how to install, the process is standard for Fabric mods. First, install Fabric Loader for your specific Minecraft version. Then, place the required dependency JARs and the add-on JAR into your mods folder. After launching the game, verify the mod is loaded in the Mods menu. If you are using a launcher like foxygame.net, the process is automated; it handles the dependency checks and keeps the mod updated automatically.

Troubleshooting Common Issues

If a skill node grants no weight, double-check that the attribute ID is exactly inventoryweight:generic.max_weight and that you are using the addition operation. You may also need to reset the skill after editing a reward so the modifier reapplies. If the built-in tree is missing, remember it is disabled by default; check the log for "Registered built-in 'carrying' datapack: true." Finally, ensure your pack.mcmeta uses strict JSON formatting, as smart quotes or trailing commas will cause errors.

Conclusion

Pufferfish's Skills - MT Inventory Weight is an elegant solution for players and modpack creators who want progression to feel meaningful. By rewarding skill development with tangible inventory capacity, it encourages exploration and crafting. With its data-driven attribute rewards and flexible event connector, it offers deep customization without requiring Java expertise. Whether you use the built-in Carrying tree or design your own, this add-on seamlessly integrates two excellent mods to enhance your Minecraft experience.

Author: KlamrFox

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