Utility Core

A library mod for NeoForge that provides shared utilities and features for mod developers and players.

Features

Recipe Conflict Resolution (Polymorph-style)

When multiple crafting recipes match the same inputs, a selection widget appears in the crafting table GUI allowing players to choose which output they want. The selected recipe is highlighted in green with a black border, and alternatives are shown with a white background.

• Server-side: Detects matching recipes, stores the player's selection via attachments, syncs the output list to the client
• Client-side: Renders a recipe selector grid, sends selection changes back to the server
• Instant update: The result slot updates immediately when clicking an alternative recipe

Damage Safety

Negative damage values from mod interactions (e.g., Apothic Attributes critical strikes + Tombstone's Decrepitude effect) are automatically clamped to 0, preventing IllegalArgumentException: Damage cannot be negative crashes that would otherwise crash the server.

Configurable

All features can be configured via the in-game config screen or the config file:

• Enable/disable the crafting recipe selector
• Maximum number of alternative recipes displayed

Developer API

Other mods can integrate with the recipe selection system using the provided PolymorphApi class.

Requirements

• NeoForge 26.1.2+
• Minecraft 26.1.2
• Both client and server

Compatibility

• Designed to be compatible with any mod
• Server-side functionality with client-side UI

Known Incompatibilities

• Fast Workbench (fastbench): This mod conflicts with Utility Core's recipe selection system. Utility Core will not function correctly if Fast Workbench is installed. Please remove Fast Workbench if you want to use the recipe selector feature.

Installation

1. Download the latest version
2. Place the jar in your mods folder on both client and server
3. Start the game/server
4. Open a crafting table and place items to see the recipe selector in action

Configuration

Configuration can be accessed via:

• In-game: Mods menu > Utility Core > Config
• File: config/utility_core-common.toml

For Developers

// Access the API
PolymorphApi api = PolymorphApi.getInstance();

// Get all recipes matching a specific input
List<RecipeHolder<CraftingRecipe>> recipes = api.getRecipesFor(
    recipeManager, RecipeType.CRAFTING, craftingInput, level
);

// Get player recipe selection data
PlayerRecipeData data = api.getPlayerRecipeData(player);

// Clear player recipe selection data
api.clearPlayerRecipeData(player);

Changelog

1.0.3

• Fixed server crash "Damage cannot be negative" when Apothic Attributes critical strike interacts with Tombstone's Decrepitude effect on Armadillos (negative damage is now clamped to 0 instead of throwing an exception).

1.0.2

• Fixed result slot not updating visually after recipe selection

1.0.1

• Initial release
• Recipe conflict resolution for crafting table: choose between multiple crafting outputs
• Configurable settings (enable/disable, max recipes displayed)
• Developer API for custom integrations
• English translations