Fishing Loot Helper API

Fishing Loot Helper API

Modrinth Page

This API makes it easy for mods to add custom fishing loot.

Right now there are just versions for 26.3, for Fabric and NeoForge.

Installation

1. Add the API .jar

Place the fishingloothelperapi.jar file into your Minecraft mods folder:

C:\Users\you\AppData\Roaming\.minecraft\mods

Also, place a copy inside your mod’s libs folder:

your-mod/
├── libs/
│   └── fishingloothelperapi.jar
├── src/
├── build.gradle
└── ...

2. Add the API to build.gradle

Change version 1.0.0 to whatever version you are using.

repositories {
    flatDir {
        dir 'libs'
    }
}

dependencies {
    implementation 'com.exline:fishingloothelperapi:1.0.0'
}

3. Add the API as a mod dependency

In neoforge.mods.toml, add:

[[dependencies.${mod_id}]]
modId="fishingloothelperapi"
type="required"
versionRange="[1.0.0,)"
ordering="NONE"
side="BOTH"

For Fabric:

Open src/main/resources/fabric.mod.json and add fishingloothelperapi to the existing depends section:

"depends": {
    "fabricloader": ">=0.19.0",
    "minecraft": "26.3",
    "fishingloothelperapi": ">=1.0.0"
}

Use the API version you are depending on.

The API .jar must also be present in the Minecraft mods folder when running the game.

Adding Fishing Loot

Register custom fishing loot with this method:

FishRegistry.registerFishingLoot(
        Items.BRAIN_CORAL,
        10,
        FishingEntry.FishingType.FISH
);

Parameters

Item (Required)

The item being added to the fishing loot can be a vanilla item or custom item.

Items.BRAIN_CORAL

Weight (Required)

The item’s weight. Higher weight means a higher chance of being selected.

10

Fishing Loot Type (Optional)

This determines which vanilla fishing pool the item is added to.

FishingEntry.FishingType.FISH

Available types:

FishingEntry.FishingType.FISH
FishingEntry.FishingType.JUNK
FishingEntry.FishingType.TREASURE

Example with a modded item

FishRegistry.registerFishingLoot(
        ModItems.ANCHOVY,
        10,
        FishingEntry.FishingType.FISH
);

Biomes

You can optionally choose which biome(s) an item can be caught in.

One Biome

FishRegistry.registerFishingLoot(
        ModItems.ANCHOVY,
        10,
        FishingEntry.FishingType.FISH,
        Biomes.OCEAN
);

Multiple Biomes

FishRegistry.registerFishingLoot(
        ModItems.ANCHOVY,
        10,
        FishingEntry.FishingType.FISH,
        Biomes.OCEAN,
        Biomes.BEACH
);

Biome Tags

You can also use biome tags instead of individual biome keys.

Multiple biome tags can be specified as well.

FishRegistry.registerFishingLoot(
        ModItems.ANCHOVY,
        10,
        FishingEntry.FishingType.FISH,
        Tags.Biomes.IS_AQUATIC
);

Any Biome

When no biomes are specified, the item can be caught in any biome.

The same applies to junk and treasure:

FishRegistry.registerFishingLoot(
        ModItems.ANCHOVY,
        10,
        FishingEntry.FishingType.FISH
);

Weights

Fishing Loot Helper API uses a weight system based on the vanilla fishing pool.

Vanilla Base Weights

Fishing Type	Base Weight
Fish	100
Junk	110
Treasure	6

Your custom loot is added to the corresponding vanilla pool.

From our earlier example, we have a weight of 10:

FishRegistry.registerFishingLoot(
        ModItems.ANCHOVY,
        10,
        FishingEntry.FishingType.FISH
);

The fish pool becomes:

Loot	Weight
Vanilla fish	100
Anchovy	10
Total	110

The Anchovy therefore has a 10/110 chance of being selected, or about 9.09%.

If you add two fish with weight 10:

Loot	Weight
Vanilla fish	100
Fish A	10
Fish B	10
Total	120

Each custom fish has a 10/120 chance of being selected, or about 8.33%.

Base Weight + Added Weights = New Total Weight

Higher weight = more common loot.

More weight added means less chance of getting vanilla loot.

However, you can also add the same vanilla loot to increase the chances again, like cod or salmon.

Vanilla Weights for Reference

Fish

Item	Weight
Cod	60
Salmon	25
Pufferfish	13
Tropical Fish	2
Total	100

Junk

Item	Weight
Lily Pad	17
Leather Boots	10
Leather	10
Water Potion	10
String	5
Fishing Rod	2
Bowl	5
Stick	5
Ink Sac	5
Tripwire Hook	5
Rotten Flesh	5
Bamboo	5
Total	110

Treasure

Item	Weight
Bow	1
Enchanted Book	1
Fishing Rod	1
Name Tag	1
Nautilus Shell	1
Saddle	1
Total	6

You can calculate an item’s chance by dividing its weight by the total weight.

For example, if we add a fish with weight 20, the chance of catching Cod goes from 60/100, or 60%, to 60/120, or 50%.

Example Mod
I made an example mod you can use to learn from or just try out. https://github.com/jexline/ogfishmod