diff --git a/README.md b/README.md
index 160f1b75..bd37b867 100644
--- a/README.md
+++ b/README.md
@@ -42,6 +42,7 @@ Just choose a version and use its version number.
 | `level_events`           | Provides common level events for mods.                                               |
 | `loot`                   | A small library to modify mob loot                                                   |
 | `mixin_extensions`       | More features for Mixins                                                             |
+| `model_data`             | Addon to model api to make building model data easier.                               |
 | `model_loader`           | Base loader for custom model types                                                   |
 | `models`                 | Model implementations, ModelData, RenderTypes                                        |
 | `obj_loader`             | Loading .obj models                                                                  |
diff --git a/modules/model_data/build.gradle b/modules/model_data/build.gradle
new file mode 100644
index 00000000..8b137891
--- /dev/null
+++ b/modules/model_data/build.gradle
@@ -0,0 +1 @@
+
diff --git a/modules/model_data/src/main/java/io/github/fabricators_of_create/porting_lib/models/data/ModelData.java b/modules/model_data/src/main/java/io/github/fabricators_of_create/porting_lib/models/data/ModelData.java
new file mode 100644
index 00000000..75d3dbc3
--- /dev/null
+++ b/modules/model_data/src/main/java/io/github/fabricators_of_create/porting_lib/models/data/ModelData.java
@@ -0,0 +1,119 @@
+package io.github.fabricators_of_create.porting_lib.models.data;
+
+import com.google.common.base.Preconditions;
+import it.unimi.dsi.fastutil.objects.Reference2ReferenceArrayMap;
+import it.unimi.dsi.fastutil.objects.Reference2ReferenceOpenHashMap;
+import java.util.Collections;
+import java.util.Map;
+import java.util.Set;
+import net.minecraft.client.renderer.RenderType;
+import net.minecraft.client.resources.model.BakedModel;
+import net.minecraft.core.BlockPos;
+import net.minecraft.core.Direction;
+import net.minecraft.util.RandomSource;
+import net.minecraft.world.level.BlockAndTintGetter;
+import net.minecraft.world.level.block.entity.BlockEntity;
+import net.minecraft.world.level.block.state.BlockState;
+import org.jetbrains.annotations.Contract;
+import org.jetbrains.annotations.Nullable;
+
+/**
+ * A container for data to be passed to {@link BakedModel} instances.
+ * <p>
+ * All objects stored in here <b>MUST BE IMMUTABLE OR THREAD-SAFE</b>.
+ * Properties will be accessed from another thread.
+ *
+ * @see ModelProperty
+ * @see BlockEntity#getRenderData()
+ * @see BakedModel#getQuads(BlockState, Direction, RandomSource)
+ */
+public final class ModelData {
+	public static final ModelData EMPTY = ModelData.builder().build();
+
+	private final Map<ModelProperty<?>, Object> properties;
+
+	@Nullable
+	private Set<ModelProperty<?>> propertySetView;
+
+	private ModelData(Map<ModelProperty<?>, Object> properties) {
+		this.properties = properties;
+	}
+
+	public Set<ModelProperty<?>> getProperties() {
+		var view = propertySetView;
+		if (view == null) {
+			propertySetView = view = Collections.unmodifiableSet(properties.keySet());
+		}
+		return view;
+	}
+
+	public boolean has(ModelProperty<?> property) {
+		return properties.containsKey(property);
+	}
+
+	@Nullable
+	public <T> T get(ModelProperty<T> property) {
+		return (T) properties.get(property);
+	}
+
+	public Builder derive() {
+		return new Builder(this);
+	}
+
+	public static Builder builder() {
+		return new Builder(null);
+	}
+
+	/**
+	 * Helper to create a {@link ModelData} instance for a single property-value pair, without the verbosity
+	 * and runtime overhead of creating a builder object.
+	 */
+	public static <T> ModelData of(ModelProperty<T> property, T value) {
+		Preconditions.checkState(property.test(value), "The provided value is invalid for this property.");
+		// Must use one of the two map types from the builder to avoid megamorphic calls to Map.get() later
+		Reference2ReferenceArrayMap<ModelProperty<?>, Object> map = new Reference2ReferenceArrayMap<>(1);
+		map.put(property, value);
+		return new ModelData(map);
+	}
+
+	public static final class Builder {
+		/**
+		 * Hash maps are slower than array maps for *extremely* small maps (empty maps or singletons are the most
+		 * extreme examples). Many block entities/models only use a single model data property, which means the
+		 * overhead of hashing is quite wasteful. However, we do want to support any number of properties with
+		 * reasonable performance. Therefore, we use an array map until the number of properties reaches this
+		 * threshold, at which point we convert it to a hash map.
+		 */
+		private static final int HASH_THRESHOLD = 4;
+
+		private Map<ModelProperty<?>, Object> properties;
+
+		private Builder(@Nullable ModelData parent) {
+			if (parent != null) {
+				// When cloning the map, use the expected type based on size
+				properties = parent.properties.size() >= HASH_THRESHOLD ? new Reference2ReferenceOpenHashMap<>(parent.properties) : new Reference2ReferenceArrayMap<>(parent.properties);
+			} else {
+				// Allocate the maximum number of entries we'd ever put into the map.
+				// We convert to a hash map *after* insertion of the HASH_THRESHOLD
+				// entry, so we need at least that many spots.
+				properties = new Reference2ReferenceArrayMap<>(HASH_THRESHOLD);
+			}
+		}
+
+		@Contract("_, _ -> this")
+		public <T> Builder with(ModelProperty<T> property, T value) {
+			Preconditions.checkState(property.test(value), "The provided value is invalid for this property.");
+			properties.put(property, value);
+			// Convert to a hash map if needed
+			if (properties.size() == HASH_THRESHOLD && properties instanceof Reference2ReferenceArrayMap<ModelProperty<?>, Object>) {
+				properties = new Reference2ReferenceOpenHashMap<>(properties);
+			}
+			return this;
+		}
+
+		@Contract("-> new")
+		public ModelData build() {
+			return new ModelData(properties);
+		}
+	}
+}
diff --git a/modules/model_data/src/main/java/io/github/fabricators_of_create/porting_lib/models/data/ModelProperty.java b/modules/model_data/src/main/java/io/github/fabricators_of_create/porting_lib/models/data/ModelProperty.java
new file mode 100644
index 00000000..1dda4c27
--- /dev/null
+++ b/modules/model_data/src/main/java/io/github/fabricators_of_create/porting_lib/models/data/ModelProperty.java
@@ -0,0 +1,28 @@
+package io.github.fabricators_of_create.porting_lib.models.data;
+
+import com.google.common.base.Predicates;
+import java.util.function.Predicate;
+
+/**
+ * A property to be used in {@link ModelData}.
+ * <p>
+ * May optionally validate incoming values.
+ *
+ * @see ModelData
+ */
+public class ModelProperty<T> implements Predicate<T> {
+	private final Predicate<T> predicate;
+
+	public ModelProperty() {
+		this(Predicates.alwaysTrue());
+	}
+
+	public ModelProperty(Predicate<T> predicate) {
+		this.predicate = predicate;
+	}
+
+	@Override
+	public boolean test(T value) {
+		return predicate.test(value);
+	}
+}
diff --git a/modules/model_data/src/main/resources/fabric.mod.json b/modules/model_data/src/main/resources/fabric.mod.json
new file mode 100644
index 00000000..1ebcf684
--- /dev/null
+++ b/modules/model_data/src/main/resources/fabric.mod.json
@@ -0,0 +1,8 @@
+
+{
+  "schemaVersion": 1,
+  "id": "porting_lib_model_data",
+  "version": "${version}",
+  "name": "Porting Lib Model Data",
+  "description": "Addon to model api to make building model data easier."
+}