API Reference

API Reference

MarieLib exposes a public Java API for mod authors who want to read player tracking state, register custom values or effects, or hook into the value system programmatically.

This page is for mod developers. If you want datapack-only integration, see Datapack Support.

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🔗 Depending on MarieLib

Add MarieLib as a dependency in your build.gradle:

dependencies {
    compileOnly "dev.marie.MariesLib:marieslib:1.0.0"
}

Declare the dependency in your mods.toml:

[[dependencies.yourmod]]
    modId = "marieslib"
    type = "required"
    versionRange = "[1.0.0,)"
    ordering = "AFTER"
    side = "BOTH"

All public API is under dev.marie.MariesLib.api. Never reference anything outside that package — internal classes are not part of the API contract.

Wire your mod through MarieLibContext at bootstrap. See Getting Started.

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📊 Reading Player State

All player queries go through MarieAPI.

Get a single value level

float proteins = MarieAPI.getValueLevel(player, "proteins");
// Returns 0.0–1.0, or -1.0 if the value key doesn't exist

Get all values at once

MariePlayerData data = MarieAPI.getTrackingData(player);
float proteins = data.values().get("proteins");
float total = data.total();
MemoryView memory = data.sourceMemory();

MariePlayerData is an immutable snapshot, safe to store and pass around.

Get total count

float total = MarieAPI.getTotal(player);
// Alias: MarieAPI.getTotalCount(player)

Check recent source history

MemoryView memory = MarieAPI.getSourceMemory(player);
boolean ateCarrots = memory.hasSourceRecently(ResourceLocation.parse("minecraft:carrot"));
List<ResourceLocation> recent = memory.getRecentSources();

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✏️ Modifying Values

// Add 10% to a player's protein bar
MarieAPI.modifyValue(player, "proteins", 0.10f);

// Remove 5% from a player's grain bar
MarieAPI.modifyValue(player, "grains", -0.05f);

modifyValue fires a ValueModifierEvent before applying. Other mods can intercept and modify or cancel the change.

Must be called server-side for changes to sync to clients correctly.

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📋 Registration

All registration must happen during mod initialization before the server starts. Calling registration methods after init throws IllegalStateException.

Register a custom value

ValueDefinition spices = ValueDefinition.builder("spices")
    .displayName("Spices")
    .color(0xFFE8A020)
    .defaultDecayRate(0.0005f)
    .lowThreshold(0.25f)
    .excessThreshold(0.9f)
    .build();

MarieAPI.registerValue(spices);

Register a source classification

MarieAPI.registerSourceClassification(
    ResourceLocation.parse("mymod:spicy_pepper"),
    "spices",
    0.08f
);

Register a custom effect

ThresholdEffect effect = ThresholdEffect.builder()
    .valueKey("spices")
    .threshold(0.2f)
    .thresholdType(ThresholdEffect.ThresholdType.LOW)
    .effectId(ResourceLocation.parse("minecraft:weakness"))
    .amplifier(0)
    .duration(300)
    .build();

MarieAPI.registerCustomEffect(effect);

ThresholdType options:

• CRITICAL / LOW — penalty fires when value is below threshold
• EXCESS / BONUS — buff fires when value is above threshold

Register a compat entry

CompatDefinition compat = CompatDefinition.builder("mymod")
    .category(CompatDefinition.CompatCategory.SOURCE_MOD)
    .addSourceMapping(ResourceLocation.parse("mymod:spicy_stew"), "spices")
    .addSourceMapping(ResourceLocation.parse("mymod:herb_salad"), "vegetables")
    .build();

MarieAPI.registerCompatEntry(compat);

CompatDefinition lives in dev.marie.MariesLib.compat.CompatDefinition.

Register a tracking profile

ProfileDefinition profile = ProfileDefinition.builder("hardcore")
    .displayName("Hardcore")
    .description("Values decay faster.")
    .customDecayRate("proteins", 0.002f)
    .customDecayRate("grains", 0.002f)
    .build();

MarieAPI.registerTrackingProfile(profile);

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📡 Events

Subscribe to MarieLib events on the NeoForge event bus.

ValueChangedEvent

Fires after a value changes. Not cancellable.

@SubscribeEvent
public void onValueChanged(MarieEvents.ValueChangedEvent event) {
    Player player = event.getPlayer();
    String key = event.getValueKey();
    float oldVal = event.getOldValue();
    float newVal = event.getNewValue();
}

ValueCriticalEvent

Fires once when a value crosses below the critical threshold. Not cancellable.

ValueExcessEvent

Fires once when a value crosses above the excess threshold. Not cancellable.

SourceAppliedEvent

Fires after a player applies a source item and gains value.

@SubscribeEvent
public void onSourceApplied(MarieEvents.SourceAppliedEvent event) {
    ResourceLocation source = event.getSourceId();
    String valueKey = event.getValueKey();
    float gained = event.getAmount();
}

ValueModifierEvent ⚡ Cancellable

Fires before a value gain is applied. Modify the amount or cancel entirely.

@SubscribeEvent
public void onValueGain(ValueModifierEvent event) {
    if (event.getValueKey().equals("proteins") && playerHasDebuff(event.getPlayer())) {
        event.setAmount(event.getAmount() * 0.5f);
    }

    if (event.getSourceId().equals(ResourceLocation.parse("mymod:poison_apple"))) {
        event.setCanceled(true);
    }
}

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🔧 Hooks & Modifiers

AbsorptionModifier @Experimental

Dynamically adjusts how much of a value a player absorbs based on their state.

public class IllnessAbsorptionModifier implements AbsorptionModifier {
    @Override
    public String getModifierId() { return "mymod:illness_penalty"; }

    @Override
    public float getAbsorptionMultiplier(Player player, String valueKey, float baseAmount) {
        if (player.hasEffect(MobEffects.NAUSEA)) return 0.5f;
        return 1.0f;
    }
}

MarieAPI.registerAbsorptionModifier(new IllnessAbsorptionModifier());

Return values: 1.0 = no change, 0.5 = half absorption, 0.0 = blocked entirely.

MarieSeasonHook @Experimental

Integrates with season mods to vary decay and absorption by season.

ReportProvider @Experimental

Injects custom sections into the consuming mod's /report command output.

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🏷️ API Stability

Annotation	Meaning
@ApiStatus.Stable	Safe to use — breaking changes require a major version bump
@ApiStatus.Experimental	May change without warning
@ApiStatus.Internal	Not for external use

Everything in MarieAPI is @Stable unless otherwise annotated.

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⚠️ What's Not Wired Yet

These registration methods exist but underlying systems may not be fully active in all consuming mods:

• registerValueSynergy: two-value interaction effects
• registerSourcePairSynergy: source combo bonuses
• registerMilestone: cumulative value goals

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📚 Related Pages

• KubeJS Scripting
• Datapack Support
• Compatibility Guide
• Getting Started