I don't know...

src/main/java/io/github/skippyall/minions/minion/MinionData.java

@@ -1,45 +1,57 @@
 package io.github.skippyall.minions.minion;
 
+import com.mojang.serialization.Codec;
+import com.mojang.serialization.codecs.RecordCodecBuilder;
+import eu.pb4.polymer.core.api.other.PolymerComponent;
+import io.github.skippyall.minions.Minions;
 import io.github.skippyall.minions.fakeplayer.MinionFakePlayer;
+import net.minecraft.component.ComponentType;
 import net.minecraft.nbt.NbtCompound;
+import net.minecraft.nbt.NbtOps;
+import net.minecraft.registry.Registries;
+import net.minecraft.registry.Registry;
+import net.minecraft.util.Identifier;
+import net.minecraft.util.Uuids;
+import org.jetbrains.annotations.NotNull;
 
+import java.util.Optional;
 import java.util.UUID;
 
-public class MinionData {
-    public UUID uuid;
-    public String name;
-    public UUID skinUuid;
+public record MinionData(UUID uuid, String name, @NotNull Optional<UUID> skinUuid) {
+    public static final Codec<MinionData> CODEC = RecordCodecBuilder.create(instance ->
+            instance.group(
+                    Uuids.CODEC.fieldOf("uuid").forGetter(MinionData::uuid),
+                    Codec.STRING.fieldOf("name").forGetter(MinionData::name),
+                    Uuids.CODEC.optionalFieldOf("skinUuid").orElse(Optional.empty()).forGetter(MinionData::skinUuid)
+            ).apply(instance, MinionData::new)
+    );
+    public static final ComponentType<MinionData> COMPONENT = Registry.register(Registries.DATA_COMPONENT_TYPE, Identifier.of(Minions.MOD_ID, "minion_data"), ComponentType.<MinionData>builder().codec(CODEC).build());
 
-    public MinionData(UUID uuid, String name, UUID skinUuid) {
-        this.uuid = uuid;
-        this.name = name;
-        this.skinUuid = skinUuid;
+    public MinionData withUuid(UUID uuid) {
+        return new MinionData(uuid, name, skinUuid);
+    }
+
+    public MinionData withName(String name) {
+        return new MinionData(uuid, name, skinUuid);
+    }
+
+    public MinionData withSkin(Optional<UUID> skinUuid) {
+        return new MinionData(uuid, name, skinUuid);
     }
 
     public NbtCompound writeNbt() {
-        NbtCompound nbt = new NbtCompound();
-
-        nbt.putUuid("uuid", uuid);
-        nbt.putString("name", name);
-        if(skinUuid != null) {
-            nbt.putUuid("skinUuid", skinUuid);
-        }
-
-        return nbt;
+        return (NbtCompound) MinionData.CODEC.encode(this, NbtOps.INSTANCE, null).getOrThrow();
     }
 
     public static MinionData readNbt(NbtCompound nbt) {
-        UUID uuid = nbt.getUuid("uuid");
-        String name = nbt.getString("name");
-        UUID skinUuid = null;
-        if(nbt.contains("skinUuid")) {
-            skinUuid = nbt.getUuid("skinUuid");
-        }
-
-        return new MinionData(uuid, name, skinUuid);
+        return MinionData.CODEC.decode(NbtOps.INSTANCE, nbt).getOrThrow().getFirst();
     }
 
     public static MinionData fromMinion(MinionFakePlayer minion) {
         return new MinionData(minion.getUuid(), minion.getMinionName(), minion.getSkinUuid());
     }
+
+    public static void register() {
+        PolymerComponent.registerDataComponent(COMPONENT);
+    }
 }