Skip to main content
General Mechanics registers three custom recipe types. All three follow the standard NeoForge RecipeType / RecipeSerializer pattern and integrate with JEI automatically.

​
Recipe types

Recipe typeRecipe classSerializer constant
gm:fabricationFabricationRecipeCoreRecipes.FABRICATION_SERIALIZER
gm:crushingCrushingRecipeCoreRecipes.CRUSHING_SERIALIZER
gm:fluid_mixingFluidMixingRecipeCoreRecipes.FLUID_MIXING_SERIALIZER

​
CoreRecipes

CoreRecipes holds the DeferredHolder references for all serializers and recipe types. 
// Serializers
DeferredHolder<RecipeSerializer<?>, RecipeSerializer<FabricationRecipe>>  FABRICATION_SERIALIZER
DeferredHolder<RecipeSerializer<?>, RecipeSerializer<CrushingRecipe>>    CRUSHING_SERIALIZER
DeferredHolder<RecipeSerializer<?>, RecipeSerializer<FluidMixingRecipe>> FLUID_MIXING_SERIALIZER

// RecipeType instances (created with RecipeType.simple)
DeferredHolder<RecipeType<?>, RecipeType<FabricationRecipe>>  FABRICATION_RECIPE_TYPE
DeferredHolder<RecipeType<?>, RecipeType<CrushingRecipe>>    CRUSHING_RECIPE_TYPE
DeferredHolder<RecipeType<?>, RecipeType<FluidMixingRecipe>> FLUID_MIXING_RECIPE_TYPE
Each recipe type is registered via RecipeType.simple(ResourceLocation) where the ResourceLocation is gm:<name>.

​
gm:fabrication

FabricationRecipe takes up to 3 unordered ingredients and produces one item output. 
public record FabricationRecipe(
    NonNullList<Ingredient> inputItems,  // 1–3 ingredients
    ItemStack output
)
Matching is order-independent: each required ingredient is matched against the provided items in the input container, and each candidate item is consumed from the pool once matched.

​
JSON format

{
  "type": "gm:fabrication",
  "ingredients": [
    { "item": "minecraft:iron_ingot" },
    { "item": "minecraft:redstone" },
    { "tag": "c:ingots/copper" }
  ],
  "result": {
    "id": "mymod:circuit_board",
    "count": 1
  }
}
​
ingredients
array
required
List of 1–3 ingredient objects. Order does not matter during matching.
​
result
ItemStack
required
Output item stack with id and optional count.

​
gm:crushing

CrushingRecipe takes a single ingredient and produces one item output. Used for ore processing and pulverizing. 
public record CrushingRecipe(
    Ingredient input,
    ItemStack output
)

​
JSON format

{
  "type": "gm:crushing",
  "ingredient": { "item": "minecraft:iron_ore" },
  "result": {
    "id": "gm:iron_dust",
    "count": 2
  }
}
​
ingredient
Ingredient
required
A single ingredient object (item or tag).
​
result
ItemStack
required
Output item stack.

​
gm:fluid_mixing

FluidMixingRecipe takes 1–3 fluid inputs (as SizedFluidIngredient) and produces a FluidStack output. Item output is not supported; the result is always a fluid. 
public record FluidMixingRecipe(
    List<SizedFluidIngredient> inputs,  // 1–3 entries
    FluidStack result
)
Input matching is order-independent, following the same pool-depletion algorithm as FabricationRecipe.

​
JSON format

{
  "type": "gm:fluid_mixing",
  "inputs": [
    {
      "fluid": "gm:source_sulfuric_acid",
      "amount": 500
    },
    {
      "fluid": "gm:source_distilled_water",
      "amount": 500
    }
  ],
  "result": {
    "fluid": "gm:source_hydrochloric_acid",
    "amount": 1000
  }
}
​
inputs
array
required
List of 1–3 sized fluid ingredient objects, each with fluid (registry ID of the source fluid) and amount in millibuckets.
​
result
FluidStack
required
Output fluid with fluid registry ID and amount in millibuckets.

​
Datapack placement

Place recipe JSON files under: 
data/<namespace>/recipe/<filename>.json
For example, a fabrication recipe in your mod mymod would go at: 
data/mymod/recipe/circuit_board.json
The recipe directory (without an s) is the correct NeoForge 1.21+ path. Earlier versions used recipes.

​
Querying recipes at runtime

Use RecipeManager to look up recipes during server-side tick logic: 
import net.minecraft.world.item.crafting.RecipeManager;
import net.minecraft.world.item.crafting.RecipeHolder;
import general.mechanics.recipes.FabricationRecipe;
import general.mechanics.recipes.FabricationRecipe.FabricationRecipeInput;
import general.mechanics.registries.CoreRecipes;

public void findRecipe(Level level, List<ItemStack> inputItems) {
    RecipeManager manager = level.getRecipeManager();

    FabricationRecipeInput input = FabricationRecipeInput.of(inputItems);

    Optional<RecipeHolder<FabricationRecipe>> match =
        manager.getRecipeFor(
            CoreRecipes.FABRICATION_RECIPE_TYPE.get(),
            input,
            level
        );

    match.ifPresent(holder -> {
        FabricationRecipe recipe = holder.value();
        ItemStack result = recipe.assemble(input, level.registryAccess());
        // use result ...
    });
}
The same pattern applies to CrushingRecipe (using CRUSHING_RECIPE_TYPE and CrushingRecipeInput) and FluidMixingRecipe (using FLUID_MIXING_RECIPE_TYPE and MixingInput).

​
JEI integration

All three recipe types are displayed automatically in JEI through the mod’s built-in JEI plugin. No additional registration is required from addon mods; adding a valid JSON recipe file is sufficient for it to appear in JEI’s recipe lookup.

Build docs developers (and LLMs) love

Get started for freeTalk to us