From 26c76215301832fb66b72e36eda55773cd1cf0e0 Mon Sep 17 00:00:00 2001
From: Adam Pocock <adam.pocock@oracle.com>
Date: Fri, 9 Sep 2022 21:15:26 -0400
Subject: [PATCH] Adding protobuf serialization for liblinear models.

---
 .../liblinear/LibLinearAnomalyModel.java      |   45 +-
 .../LibLinearAnomalyTrainerTest.java          |    3 +-
 .../LibLinearClassificationModel.java         |   45 +-
 .../liblinear/TestLibLinearModel.java         |    2 +
 .../common/liblinear/LibLinearModel.java      |  113 +-
 .../liblinear/protos/LibLinearModelProto.java |  777 +++++++++++
 .../protos/LibLinearModelProtoOrBuilder.java  |   41 +
 .../liblinear/protos/LibLinearProto.java      | 1178 +++++++++++++++++
 .../protos/LibLinearProtoOrBuilder.java       |   79 ++
 .../liblinear/protos/TribuoLiblinear.java     |   67 +
 .../resources/protos/tribuo-liblinear.proto   |   49 +
 .../liblinear/LibLinearRegressionModel.java   |   49 +-
 .../regression/liblinear/TestLibLinear.java   |    3 +-
 13 files changed, 2445 insertions(+), 6 deletions(-)
 create mode 100644 Common/LibLinear/src/main/java/org/tribuo/common/liblinear/protos/LibLinearModelProto.java
 create mode 100644 Common/LibLinear/src/main/java/org/tribuo/common/liblinear/protos/LibLinearModelProtoOrBuilder.java
 create mode 100644 Common/LibLinear/src/main/java/org/tribuo/common/liblinear/protos/LibLinearProto.java
 create mode 100644 Common/LibLinear/src/main/java/org/tribuo/common/liblinear/protos/LibLinearProtoOrBuilder.java
 create mode 100644 Common/LibLinear/src/main/java/org/tribuo/common/liblinear/protos/TribuoLiblinear.java
 create mode 100644 Common/LibLinear/src/main/resources/protos/tribuo-liblinear.proto

diff --git a/AnomalyDetection/LibLinear/src/main/java/org/tribuo/anomaly/liblinear/LibLinearAnomalyModel.java b/AnomalyDetection/LibLinear/src/main/java/org/tribuo/anomaly/liblinear/LibLinearAnomalyModel.java
index 114acdf48..2669c7c2e 100644
--- a/AnomalyDetection/LibLinear/src/main/java/org/tribuo/anomaly/liblinear/LibLinearAnomalyModel.java
+++ b/AnomalyDetection/LibLinear/src/main/java/org/tribuo/anomaly/liblinear/LibLinearAnomalyModel.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2021, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2021, 2022 Oracle and/or its affiliates. All rights reserved.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,6 +16,8 @@
 
 package org.tribuo.anomaly.liblinear;
 
+import com.google.protobuf.Any;
+import com.google.protobuf.InvalidProtocolBufferException;
 import com.oracle.labs.mlrg.olcut.util.Pair;
 import org.tribuo.Example;
 import org.tribuo.Excuse;
@@ -27,10 +29,15 @@
 import org.tribuo.anomaly.Event;
 import org.tribuo.common.liblinear.LibLinearModel;
 import org.tribuo.common.liblinear.LibLinearTrainer;
+import org.tribuo.common.liblinear.protos.LibLinearModelProto;
+import org.tribuo.impl.ModelDataCarrier;
 import org.tribuo.provenance.ModelProvenance;
 import de.bwaldvogel.liblinear.FeatureNode;
 import de.bwaldvogel.liblinear.Linear;
 
+import java.io.ByteArrayInputStream;
+import java.io.IOException;
+import java.io.ObjectInputStream;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.Comparator;
@@ -67,6 +74,42 @@ public class LibLinearAnomalyModel extends LibLinearModel<Event> {
         super(name, description, featureIDMap, outputIDInfo, false, models);
     }
 
+    /**
+     * Deserialization factory.
+     * @param version The serialized object version.
+     * @param className The class name.
+     * @param message The serialized data.
+     */
+    public static LibLinearAnomalyModel deserializeFromProto(int version, String className, Any message) throws InvalidProtocolBufferException {
+        if (version < 0 || version > CURRENT_VERSION) {
+            throw new IllegalArgumentException("Unknown version " + version + ", this class supports at most version " + CURRENT_VERSION);
+        }
+        if (!"org.tribuo.anomaly.liblinear.LibLinearAnomalyModel".equals(className)) {
+            throw new IllegalStateException("Invalid protobuf, this class can only deserialize LibLinearAnomalyModel");
+        }
+        LibLinearModelProto proto = message.unpack(LibLinearModelProto.class);
+
+        ModelDataCarrier<?> carrier = ModelDataCarrier.deserialize(proto.getMetadata());
+        if (!carrier.outputDomain().getOutput(0).getClass().equals(Event.class)) {
+            throw new IllegalStateException("Invalid protobuf, output domain is not an anomaly domain, found " + carrier.outputDomain().getClass());
+        }
+        @SuppressWarnings("unchecked") // guarded by getClass
+        ImmutableOutputInfo<Event> outputDomain = (ImmutableOutputInfo<Event>) carrier.outputDomain();
+
+        if (proto.getModelsCount() != 1) {
+            throw new IllegalStateException("Invalid protobuf, expected 1 model, found " + proto.getModelsCount());
+        }
+        try {
+            ByteArrayInputStream bais = new ByteArrayInputStream(proto.getModels(0).toByteArray());
+            ObjectInputStream ois = new ObjectInputStream(bais);
+            de.bwaldvogel.liblinear.Model model = (de.bwaldvogel.liblinear.Model) ois.readObject();
+            ois.close();
+            return new LibLinearAnomalyModel(carrier.name(),carrier.provenance(),carrier.featureDomain(),outputDomain,Collections.singletonList(model));
+        } catch (IOException | ClassNotFoundException e) {
+            throw new IllegalStateException("Invalid protobuf, failed to deserialize liblinear model", e);
+        }
+    }
+
     @Override
     public Prediction<Event> predict(Example<Event> example) {
         FeatureNode[] features = LibLinearTrainer.exampleToNodes(example, featureIDMap, null);
diff --git a/AnomalyDetection/LibLinear/src/test/java/org/tribuo/anomaly/liblinear/LibLinearAnomalyTrainerTest.java b/AnomalyDetection/LibLinear/src/test/java/org/tribuo/anomaly/liblinear/LibLinearAnomalyTrainerTest.java
index ac05399b8..e66eb7bf1 100644
--- a/AnomalyDetection/LibLinear/src/test/java/org/tribuo/anomaly/liblinear/LibLinearAnomalyTrainerTest.java
+++ b/AnomalyDetection/LibLinear/src/test/java/org/tribuo/anomaly/liblinear/LibLinearAnomalyTrainerTest.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2021, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2021, 2022 Oracle and/or its affiliates. All rights reserved.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -66,6 +66,7 @@ public void gaussianDataTest() {
 
         // Test serialization
         Helpers.testModelSerialization(model,Event.class);
+        Helpers.testModelProtoSerialization(model,Event.class,testData);
     }
 
 }
diff --git a/Classification/LibLinear/src/main/java/org/tribuo/classification/liblinear/LibLinearClassificationModel.java b/Classification/LibLinear/src/main/java/org/tribuo/classification/liblinear/LibLinearClassificationModel.java
index 462e23b09..5b082bfb3 100644
--- a/Classification/LibLinear/src/main/java/org/tribuo/classification/liblinear/LibLinearClassificationModel.java
+++ b/Classification/LibLinear/src/main/java/org/tribuo/classification/liblinear/LibLinearClassificationModel.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2015-2021, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2015, 2022, Oracle and/or its affiliates. All rights reserved.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -17,6 +17,8 @@
 package org.tribuo.classification.liblinear;
 
 import ai.onnx.proto.OnnxMl;
+import com.google.protobuf.Any;
+import com.google.protobuf.InvalidProtocolBufferException;
 import com.oracle.labs.mlrg.olcut.util.Pair;
 import de.bwaldvogel.liblinear.FeatureNode;
 import de.bwaldvogel.liblinear.Linear;
@@ -31,6 +33,8 @@
 import org.tribuo.classification.Label;
 import org.tribuo.common.liblinear.LibLinearModel;
 import org.tribuo.common.liblinear.LibLinearTrainer;
+import org.tribuo.common.liblinear.protos.LibLinearModelProto;
+import org.tribuo.impl.ModelDataCarrier;
 import org.tribuo.provenance.ModelProvenance;
 import org.tribuo.util.onnx.ONNXContext;
 import org.tribuo.util.onnx.ONNXInitializer;
@@ -39,6 +43,9 @@
 import org.tribuo.util.onnx.ONNXPlaceholder;
 import org.tribuo.util.onnx.ONNXRef;
 
+import java.io.ByteArrayInputStream;
+import java.io.IOException;
+import java.io.ObjectInputStream;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collections;
@@ -104,6 +111,42 @@ public class LibLinearClassificationModel extends LibLinearModel<Label> implemen
         }
     }
 
+    /**
+     * Deserialization factory.
+     * @param version The serialized object version.
+     * @param className The class name.
+     * @param message The serialized data.
+     */
+    public static LibLinearClassificationModel deserializeFromProto(int version, String className, Any message) throws InvalidProtocolBufferException {
+        if (version < 0 || version > CURRENT_VERSION) {
+            throw new IllegalArgumentException("Unknown version " + version + ", this class supports at most version " + CURRENT_VERSION);
+        }
+        if (!"org.tribuo.classification.liblinear.LibLinearClassificationModel".equals(className)) {
+            throw new IllegalStateException("Invalid protobuf, this class can only deserialize LibLinearClassificationModel");
+        }
+        LibLinearModelProto proto = message.unpack(LibLinearModelProto.class);
+
+        ModelDataCarrier<?> carrier = ModelDataCarrier.deserialize(proto.getMetadata());
+        if (!carrier.outputDomain().getOutput(0).getClass().equals(Label.class)) {
+            throw new IllegalStateException("Invalid protobuf, output domain is not a label domain, found " + carrier.outputDomain().getClass());
+        }
+        @SuppressWarnings("unchecked") // guarded by getClass
+        ImmutableOutputInfo<Label> outputDomain = (ImmutableOutputInfo<Label>) carrier.outputDomain();
+
+        if (proto.getModelsCount() != 1) {
+            throw new IllegalStateException("Invalid protobuf, expected 1 model, found " + proto.getModelsCount());
+        }
+        try {
+            ByteArrayInputStream bais = new ByteArrayInputStream(proto.getModels(0).toByteArray());
+            ObjectInputStream ois = new ObjectInputStream(bais);
+            de.bwaldvogel.liblinear.Model model = (de.bwaldvogel.liblinear.Model) ois.readObject();
+            ois.close();
+            return new LibLinearClassificationModel(carrier.name(),carrier.provenance(),carrier.featureDomain(),outputDomain,Collections.singletonList(model));
+        } catch (IOException | ClassNotFoundException e) {
+            throw new IllegalStateException("Invalid protobuf, failed to deserialize liblinear model", e);
+        }
+    }
+
     @Override
     public Prediction<Label> predict(Example<Label> example) {
         FeatureNode[] features = LibLinearTrainer.exampleToNodes(example, featureIDMap, null);
diff --git a/Classification/LibLinear/src/test/java/org/tribuo/classification/liblinear/TestLibLinearModel.java b/Classification/LibLinear/src/test/java/org/tribuo/classification/liblinear/TestLibLinearModel.java
index 076329bb0..3e954dc61 100644
--- a/Classification/LibLinear/src/test/java/org/tribuo/classification/liblinear/TestLibLinearModel.java
+++ b/Classification/LibLinear/src/test/java/org/tribuo/classification/liblinear/TestLibLinearModel.java
@@ -212,6 +212,8 @@ public void testDenseData() {
 
         // Test serialization
         Helpers.testModelSerialization(model,Label.class);
+
+        Helpers.testModelProtoSerialization(model, Label.class, p.getB());
     }
 
     @Test
diff --git a/Common/LibLinear/src/main/java/org/tribuo/common/liblinear/LibLinearModel.java b/Common/LibLinear/src/main/java/org/tribuo/common/liblinear/LibLinearModel.java
index 5d2f42c8c..3205c08bc 100644
--- a/Common/LibLinear/src/main/java/org/tribuo/common/liblinear/LibLinearModel.java
+++ b/Common/LibLinear/src/main/java/org/tribuo/common/liblinear/LibLinearModel.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2015-2021, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2015, 2022, Oracle and/or its affiliates. All rights reserved.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -16,23 +16,36 @@
 
 package org.tribuo.common.liblinear;
 
+import com.google.protobuf.Any;
+import com.google.protobuf.ByteString;
 import de.bwaldvogel.liblinear.Linear;
+import de.bwaldvogel.liblinear.SolverType;
 import org.tribuo.Example;
 import org.tribuo.Excuse;
 import org.tribuo.ImmutableFeatureMap;
 import org.tribuo.ImmutableOutputInfo;
 import org.tribuo.Model;
 import org.tribuo.Output;
+import org.tribuo.common.liblinear.protos.LibLinearModelProto;
+import org.tribuo.common.liblinear.protos.LibLinearProto;
+import org.tribuo.impl.ModelDataCarrier;
+import org.tribuo.protos.core.ModelProto;
 import org.tribuo.provenance.ModelProvenance;
+import org.tribuo.util.Util;
 
+import java.io.ByteArrayOutputStream;
 import java.io.IOException;
+import java.io.ObjectOutputStream;
 import java.io.StringReader;
 import java.io.StringWriter;
+import java.lang.reflect.Field;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;
 import java.util.Optional;
 import java.util.logging.Logger;
+import java.util.stream.Collectors;
 
 /**
  * A {@link Model} which wraps a LibLinear-java model.
@@ -57,6 +70,11 @@ public abstract class LibLinearModel<T extends Output<T>> extends Model<T> {
 
     private static final Logger logger = Logger.getLogger(LibLinearModel.class.getName());
 
+    /**
+     * Protobuf serialization version.
+     */
+    public static final int CURRENT_VERSION = 0;
+
     /**
      * The list of LibLinear models. Multiple models are used by multi-label and multidimensional regression outputs.
      * <p>
@@ -163,4 +181,97 @@ protected static de.bwaldvogel.liblinear.Model copyModel(de.bwaldvogel.liblinear
      * @return An excuse for this example.
      */
     protected abstract Excuse<T> innerGetExcuse(Example<T> e, double[][] featureWeights);
+
+    @Override
+    public ModelProto serialize() {
+        ModelDataCarrier<T> carrier = createDataCarrier();
+
+        LibLinearModelProto.Builder modelBuilder = LibLinearModelProto.newBuilder();
+        modelBuilder.setMetadata(carrier.serialize());
+        for (de.bwaldvogel.liblinear.Model m : models) {
+            try {
+                ByteArrayOutputStream baos = new ByteArrayOutputStream();
+                ObjectOutputStream oos = new ObjectOutputStream(baos);
+                oos.writeObject(m);
+                oos.close();
+                modelBuilder.addModels(ByteString.copyFrom(baos.toByteArray()));
+            } catch (IOException e) {
+                throw new IllegalStateException("Could not serialize liblinear model to byte array");
+            }
+        }
+
+        ModelProto.Builder builder = ModelProto.newBuilder();
+        builder.setSerializedData(Any.pack(modelBuilder.build()));
+        builder.setClassName(this.getClass().getName());
+        builder.setVersion(CURRENT_VERSION);
+
+        return builder.build();
+    }
+
+    /**
+     * Serialize the LibLinear model into a protobuf.
+     * <p>
+     * Note deserializing {@link LibLinearProto} requires reflective access into {@code de.bwaldvogel.liblinear.Model}
+     * and thus requires additional command line permissions when running with the module system. For the time
+     * being we use Java serialization to a byte array rather than this method and {@code LibLinearProto}.
+     * @param model The model to serialize.
+     * @return The protobuf.
+     */
+    private static LibLinearProto serializeModel(de.bwaldvogel.liblinear.Model model) {
+        LibLinearProto.Builder builder = LibLinearProto.newBuilder();
+
+        builder.setBias(model.getBias());
+        builder.addAllLabel(Arrays.stream(model.getLabels()).boxed().collect(Collectors.toList()));
+        builder.setNrClass(model.getNrClass());
+        builder.setNrFeature(model.getNrFeature());
+        builder.setSolverType(model.getSolverType().name());
+        builder.addAllW(Arrays.stream(model.getFeatureWeights()).boxed().collect(Collectors.toList()));
+        if (model.getSolverType().isOneClass()) {
+            builder.setRho(model.getDecfunRho());
+        }
+
+        return builder.build();
+    }
+
+    /**
+     * Deserialize a LibLinear model from a protobuf.
+     * <p>
+     * Note this method requires reflective access into {@code de.bwaldvogel.liblinear.Model} and thus
+     * requires additional command line permissions when running with the module system. For the time
+     * being we use Java serialization to a byte array rather than this method and {@code LibLinearProto}.
+     * @param proto The protobuf to deserialize.
+     * @return The model.
+     */
+    private static de.bwaldvogel.liblinear.Model deserializeModels(LibLinearProto proto) {
+        de.bwaldvogel.liblinear.Model model = new de.bwaldvogel.liblinear.Model();
+        Class<de.bwaldvogel.liblinear.Model> modelClass = de.bwaldvogel.liblinear.Model.class;
+        setField(modelClass, "bias", model, proto.getBias());
+        setField(modelClass, "label", model, Util.toPrimitiveInt(proto.getLabelList()));
+        setField(modelClass, "nr_class", model, proto.getNrClass());
+        setField(modelClass, "nr_feature", model, proto.getNrFeature());
+        setField(modelClass, "solverType", model, SolverType.valueOf(proto.getSolverType()));
+        setField(modelClass, "w", model, Util.toPrimitiveDouble(proto.getWList()));
+        setField(modelClass, "rho", model, proto.getRho());
+        return model;
+    }
+
+    /**
+     * Sets a field on the supplied object.
+     * <p>
+     * Wraps any exceptions in {@link IllegalStateException}.
+     * @param clazz The class.
+     * @param fieldName The field name to set.
+     * @param host The host object.
+     * @param value The new field value.
+     */
+    private static <U> void setField(Class<U> clazz, String fieldName, U host, Object value) {
+        try {
+            Field biasField = clazz.getField(fieldName);
+            biasField.setAccessible(true);
+            biasField.set(host, value);
+            biasField.setAccessible(false);
+        } catch (NoSuchFieldException | IllegalAccessException e) {
+            throw new IllegalStateException("Failed to write to field " + fieldName, e);
+        }
+    }
 }
diff --git a/Common/LibLinear/src/main/java/org/tribuo/common/liblinear/protos/LibLinearModelProto.java b/Common/LibLinear/src/main/java/org/tribuo/common/liblinear/protos/LibLinearModelProto.java
new file mode 100644
index 000000000..c8f59f736
--- /dev/null
+++ b/Common/LibLinear/src/main/java/org/tribuo/common/liblinear/protos/LibLinearModelProto.java
@@ -0,0 +1,777 @@
+// Generated by the protocol buffer compiler.  DO NOT EDIT!
+// source: tribuo-liblinear.proto
+
+package org.tribuo.common.liblinear.protos;
+
+/**
+ * <pre>
+ *LibLinearModel proto
+ * </pre>
+ *
+ * Protobuf type {@code tribuo.common.liblinear.LibLinearModelProto}
+ */
+public final class LibLinearModelProto extends
+    com.google.protobuf.GeneratedMessageV3 implements
+    // @@protoc_insertion_point(message_implements:tribuo.common.liblinear.LibLinearModelProto)
+    LibLinearModelProtoOrBuilder {
+private static final long serialVersionUID = 0L;
+  // Use LibLinearModelProto.newBuilder() to construct.
+  private LibLinearModelProto(com.google.protobuf.GeneratedMessageV3.Builder<?> builder) {
+    super(builder);
+  }
+  private LibLinearModelProto() {
+    models_ = java.util.Collections.emptyList();
+  }
+
+  @java.lang.Override
+  @SuppressWarnings({"unused"})
+  protected java.lang.Object newInstance(
+      UnusedPrivateParameter unused) {
+    return new LibLinearModelProto();
+  }
+
+  @java.lang.Override
+  public final com.google.protobuf.UnknownFieldSet
+  getUnknownFields() {
+    return this.unknownFields;
+  }
+  private LibLinearModelProto(
+      com.google.protobuf.CodedInputStream input,
+      com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+      throws com.google.protobuf.InvalidProtocolBufferException {
+    this();
+    if (extensionRegistry == null) {
+      throw new java.lang.NullPointerException();
+    }
+    int mutable_bitField0_ = 0;
+    com.google.protobuf.UnknownFieldSet.Builder unknownFields =
+        com.google.protobuf.UnknownFieldSet.newBuilder();
+    try {
+      boolean done = false;
+      while (!done) {
+        int tag = input.readTag();
+        switch (tag) {
+          case 0:
+            done = true;
+            break;
+          case 10: {
+            org.tribuo.protos.core.ModelDataProto.Builder subBuilder = null;
+            if (metadata_ != null) {
+              subBuilder = metadata_.toBuilder();
+            }
+            metadata_ = input.readMessage(org.tribuo.protos.core.ModelDataProto.parser(), extensionRegistry);
+            if (subBuilder != null) {
+              subBuilder.mergeFrom(metadata_);
+              metadata_ = subBuilder.buildPartial();
+            }
+
+            break;
+          }
+          case 18: {
+            if (!((mutable_bitField0_ & 0x00000001) != 0)) {
+              models_ = new java.util.ArrayList<com.google.protobuf.ByteString>();
+              mutable_bitField0_ |= 0x00000001;
+            }
+            models_.add(input.readBytes());
+            break;
+          }
+          default: {
+            if (!parseUnknownField(
+                input, unknownFields, extensionRegistry, tag)) {
+              done = true;
+            }
+            break;
+          }
+        }
+      }
+    } catch (com.google.protobuf.InvalidProtocolBufferException e) {
+      throw e.setUnfinishedMessage(this);
+    } catch (java.io.IOException e) {
+      throw new com.google.protobuf.InvalidProtocolBufferException(
+          e).setUnfinishedMessage(this);
+    } finally {
+      if (((mutable_bitField0_ & 0x00000001) != 0)) {
+        models_ = java.util.Collections.unmodifiableList(models_); // C
+      }
+      this.unknownFields = unknownFields.build();
+      makeExtensionsImmutable();
+    }
+  }
+  public static final com.google.protobuf.Descriptors.Descriptor
+      getDescriptor() {
+    return org.tribuo.common.liblinear.protos.TribuoLiblinear.internal_static_tribuo_common_liblinear_LibLinearModelProto_descriptor;
+  }
+
+  @java.lang.Override
+  protected com.google.protobuf.GeneratedMessageV3.FieldAccessorTable
+      internalGetFieldAccessorTable() {
+    return org.tribuo.common.liblinear.protos.TribuoLiblinear.internal_static_tribuo_common_liblinear_LibLinearModelProto_fieldAccessorTable
+        .ensureFieldAccessorsInitialized(
+            org.tribuo.common.liblinear.protos.LibLinearModelProto.class, org.tribuo.common.liblinear.protos.LibLinearModelProto.Builder.class);
+  }
+
+  public static final int METADATA_FIELD_NUMBER = 1;
+  private org.tribuo.protos.core.ModelDataProto metadata_;
+  /**
+   * <code>.tribuo.core.ModelDataProto metadata = 1;</code>
+   * @return Whether the metadata field is set.
+   */
+  @java.lang.Override
+  public boolean hasMetadata() {
+    return metadata_ != null;
+  }
+  /**
+   * <code>.tribuo.core.ModelDataProto metadata = 1;</code>
+   * @return The metadata.
+   */
+  @java.lang.Override
+  public org.tribuo.protos.core.ModelDataProto getMetadata() {
+    return metadata_ == null ? org.tribuo.protos.core.ModelDataProto.getDefaultInstance() : metadata_;
+  }
+  /**
+   * <code>.tribuo.core.ModelDataProto metadata = 1;</code>
+   */
+  @java.lang.Override
+  public org.tribuo.protos.core.ModelDataProtoOrBuilder getMetadataOrBuilder() {
+    return getMetadata();
+  }
+
+  public static final int MODELS_FIELD_NUMBER = 2;
+  private java.util.List<com.google.protobuf.ByteString> models_;
+  /**
+   * <code>repeated bytes models = 2;</code>
+   * @return A list containing the models.
+   */
+  @java.lang.Override
+  public java.util.List<com.google.protobuf.ByteString>
+      getModelsList() {
+    return models_;
+  }
+  /**
+   * <code>repeated bytes models = 2;</code>
+   * @return The count of models.
+   */
+  public int getModelsCount() {
+    return models_.size();
+  }
+  /**
+   * <code>repeated bytes models = 2;</code>
+   * @param index The index of the element to return.
+   * @return The models at the given index.
+   */
+  public com.google.protobuf.ByteString getModels(int index) {
+    return models_.get(index);
+  }
+
+  private byte memoizedIsInitialized = -1;
+  @java.lang.Override
+  public final boolean isInitialized() {
+    byte isInitialized = memoizedIsInitialized;
+    if (isInitialized == 1) return true;
+    if (isInitialized == 0) return false;
+
+    memoizedIsInitialized = 1;
+    return true;
+  }
+
+  @java.lang.Override
+  public void writeTo(com.google.protobuf.CodedOutputStream output)
+                      throws java.io.IOException {
+    if (metadata_ != null) {
+      output.writeMessage(1, getMetadata());
+    }
+    for (int i = 0; i < models_.size(); i++) {
+      output.writeBytes(2, models_.get(i));
+    }
+    unknownFields.writeTo(output);
+  }
+
+  @java.lang.Override
+  public int getSerializedSize() {
+    int size = memoizedSize;
+    if (size != -1) return size;
+
+    size = 0;
+    if (metadata_ != null) {
+      size += com.google.protobuf.CodedOutputStream
+        .computeMessageSize(1, getMetadata());
+    }
+    {
+      int dataSize = 0;
+      for (int i = 0; i < models_.size(); i++) {
+        dataSize += com.google.protobuf.CodedOutputStream
+          .computeBytesSizeNoTag(models_.get(i));
+      }
+      size += dataSize;
+      size += 1 * getModelsList().size();
+    }
+    size += unknownFields.getSerializedSize();
+    memoizedSize = size;
+    return size;
+  }
+
+  @java.lang.Override
+  public boolean equals(final java.lang.Object obj) {
+    if (obj == this) {
+     return true;
+    }
+    if (!(obj instanceof org.tribuo.common.liblinear.protos.LibLinearModelProto)) {
+      return super.equals(obj);
+    }
+    org.tribuo.common.liblinear.protos.LibLinearModelProto other = (org.tribuo.common.liblinear.protos.LibLinearModelProto) obj;
+
+    if (hasMetadata() != other.hasMetadata()) return false;
+    if (hasMetadata()) {
+      if (!getMetadata()
+          .equals(other.getMetadata())) return false;
+    }
+    if (!getModelsList()
+        .equals(other.getModelsList())) return false;
+    if (!unknownFields.equals(other.unknownFields)) return false;
+    return true;
+  }
+
+  @java.lang.Override
+  public int hashCode() {
+    if (memoizedHashCode != 0) {
+      return memoizedHashCode;
+    }
+    int hash = 41;
+    hash = (19 * hash) + getDescriptor().hashCode();
+    if (hasMetadata()) {
+      hash = (37 * hash) + METADATA_FIELD_NUMBER;
+      hash = (53 * hash) + getMetadata().hashCode();
+    }
+    if (getModelsCount() > 0) {
+      hash = (37 * hash) + MODELS_FIELD_NUMBER;
+      hash = (53 * hash) + getModelsList().hashCode();
+    }
+    hash = (29 * hash) + unknownFields.hashCode();
+    memoizedHashCode = hash;
+    return hash;
+  }
+
+  public static org.tribuo.common.liblinear.protos.LibLinearModelProto parseFrom(
+      java.nio.ByteBuffer data)
+      throws com.google.protobuf.InvalidProtocolBufferException {
+    return PARSER.parseFrom(data);
+  }
+  public static org.tribuo.common.liblinear.protos.LibLinearModelProto parseFrom(
+      java.nio.ByteBuffer data,
+      com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+      throws com.google.protobuf.InvalidProtocolBufferException {
+    return PARSER.parseFrom(data, extensionRegistry);
+  }
+  public static org.tribuo.common.liblinear.protos.LibLinearModelProto parseFrom(
+      com.google.protobuf.ByteString data)
+      throws com.google.protobuf.InvalidProtocolBufferException {
+    return PARSER.parseFrom(data);
+  }
+  public static org.tribuo.common.liblinear.protos.LibLinearModelProto parseFrom(
+      com.google.protobuf.ByteString data,
+      com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+      throws com.google.protobuf.InvalidProtocolBufferException {
+    return PARSER.parseFrom(data, extensionRegistry);
+  }
+  public static org.tribuo.common.liblinear.protos.LibLinearModelProto parseFrom(byte[] data)
+      throws com.google.protobuf.InvalidProtocolBufferException {
+    return PARSER.parseFrom(data);
+  }
+  public static org.tribuo.common.liblinear.protos.LibLinearModelProto parseFrom(
+      byte[] data,
+      com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+      throws com.google.protobuf.InvalidProtocolBufferException {
+    return PARSER.parseFrom(data, extensionRegistry);
+  }
+  public static org.tribuo.common.liblinear.protos.LibLinearModelProto parseFrom(java.io.InputStream input)
+      throws java.io.IOException {
+    return com.google.protobuf.GeneratedMessageV3
+        .parseWithIOException(PARSER, input);
+  }
+  public static org.tribuo.common.liblinear.protos.LibLinearModelProto parseFrom(
+      java.io.InputStream input,
+      com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+      throws java.io.IOException {
+    return com.google.protobuf.GeneratedMessageV3
+        .parseWithIOException(PARSER, input, extensionRegistry);
+  }
+  public static org.tribuo.common.liblinear.protos.LibLinearModelProto parseDelimitedFrom(java.io.InputStream input)
+      throws java.io.IOException {
+    return com.google.protobuf.GeneratedMessageV3
+        .parseDelimitedWithIOException(PARSER, input);
+  }
+  public static org.tribuo.common.liblinear.protos.LibLinearModelProto parseDelimitedFrom(
+      java.io.InputStream input,
+      com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+      throws java.io.IOException {
+    return com.google.protobuf.GeneratedMessageV3
+        .parseDelimitedWithIOException(PARSER, input, extensionRegistry);
+  }
+  public static org.tribuo.common.liblinear.protos.LibLinearModelProto parseFrom(
+      com.google.protobuf.CodedInputStream input)
+      throws java.io.IOException {
+    return com.google.protobuf.GeneratedMessageV3
+        .parseWithIOException(PARSER, input);
+  }
+  public static org.tribuo.common.liblinear.protos.LibLinearModelProto parseFrom(
+      com.google.protobuf.CodedInputStream input,
+      com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+      throws java.io.IOException {
+    return com.google.protobuf.GeneratedMessageV3
+        .parseWithIOException(PARSER, input, extensionRegistry);
+  }
+
+  @java.lang.Override
+  public Builder newBuilderForType() { return newBuilder(); }
+  public static Builder newBuilder() {
+    return DEFAULT_INSTANCE.toBuilder();
+  }
+  public static Builder newBuilder(org.tribuo.common.liblinear.protos.LibLinearModelProto prototype) {
+    return DEFAULT_INSTANCE.toBuilder().mergeFrom(prototype);
+  }
+  @java.lang.Override
+  public Builder toBuilder() {
+    return this == DEFAULT_INSTANCE
+        ? new Builder() : new Builder().mergeFrom(this);
+  }
+
+  @java.lang.Override
+  protected Builder newBuilderForType(
+      com.google.protobuf.GeneratedMessageV3.BuilderParent parent) {
+    Builder builder = new Builder(parent);
+    return builder;
+  }
+  /**
+   * <pre>
+   *LibLinearModel proto
+   * </pre>
+   *
+   * Protobuf type {@code tribuo.common.liblinear.LibLinearModelProto}
+   */
+  public static final class Builder extends
+      com.google.protobuf.GeneratedMessageV3.Builder<Builder> implements
+      // @@protoc_insertion_point(builder_implements:tribuo.common.liblinear.LibLinearModelProto)
+      org.tribuo.common.liblinear.protos.LibLinearModelProtoOrBuilder {
+    public static final com.google.protobuf.Descriptors.Descriptor
+        getDescriptor() {
+      return org.tribuo.common.liblinear.protos.TribuoLiblinear.internal_static_tribuo_common_liblinear_LibLinearModelProto_descriptor;
+    }
+
+    @java.lang.Override
+    protected com.google.protobuf.GeneratedMessageV3.FieldAccessorTable
+        internalGetFieldAccessorTable() {
+      return org.tribuo.common.liblinear.protos.TribuoLiblinear.internal_static_tribuo_common_liblinear_LibLinearModelProto_fieldAccessorTable
+          .ensureFieldAccessorsInitialized(
+              org.tribuo.common.liblinear.protos.LibLinearModelProto.class, org.tribuo.common.liblinear.protos.LibLinearModelProto.Builder.class);
+    }
+
+    // Construct using org.tribuo.common.liblinear.protos.LibLinearModelProto.newBuilder()
+    private Builder() {
+      maybeForceBuilderInitialization();
+    }
+
+    private Builder(
+        com.google.protobuf.GeneratedMessageV3.BuilderParent parent) {
+      super(parent);
+      maybeForceBuilderInitialization();
+    }
+    private void maybeForceBuilderInitialization() {
+      if (com.google.protobuf.GeneratedMessageV3
+              .alwaysUseFieldBuilders) {
+      }
+    }
+    @java.lang.Override
+    public Builder clear() {
+      super.clear();
+      if (metadataBuilder_ == null) {
+        metadata_ = null;
+      } else {
+        metadata_ = null;
+        metadataBuilder_ = null;
+      }
+      models_ = java.util.Collections.emptyList();
+      bitField0_ = (bitField0_ & ~0x00000001);
+      return this;
+    }
+
+    @java.lang.Override
+    public com.google.protobuf.Descriptors.Descriptor
+        getDescriptorForType() {
+      return org.tribuo.common.liblinear.protos.TribuoLiblinear.internal_static_tribuo_common_liblinear_LibLinearModelProto_descriptor;
+    }
+
+    @java.lang.Override
+    public org.tribuo.common.liblinear.protos.LibLinearModelProto getDefaultInstanceForType() {
+      return org.tribuo.common.liblinear.protos.LibLinearModelProto.getDefaultInstance();
+    }
+
+    @java.lang.Override
+    public org.tribuo.common.liblinear.protos.LibLinearModelProto build() {
+      org.tribuo.common.liblinear.protos.LibLinearModelProto result = buildPartial();
+      if (!result.isInitialized()) {
+        throw newUninitializedMessageException(result);
+      }
+      return result;
+    }
+
+    @java.lang.Override
+    public org.tribuo.common.liblinear.protos.LibLinearModelProto buildPartial() {
+      org.tribuo.common.liblinear.protos.LibLinearModelProto result = new org.tribuo.common.liblinear.protos.LibLinearModelProto(this);
+      int from_bitField0_ = bitField0_;
+      if (metadataBuilder_ == null) {
+        result.metadata_ = metadata_;
+      } else {
+        result.metadata_ = metadataBuilder_.build();
+      }
+      if (((bitField0_ & 0x00000001) != 0)) {
+        models_ = java.util.Collections.unmodifiableList(models_);
+        bitField0_ = (bitField0_ & ~0x00000001);
+      }
+      result.models_ = models_;
+      onBuilt();
+      return result;
+    }
+
+    @java.lang.Override
+    public Builder clone() {
+      return super.clone();
+    }
+    @java.lang.Override
+    public Builder setField(
+        com.google.protobuf.Descriptors.FieldDescriptor field,
+        java.lang.Object value) {
+      return super.setField(field, value);
+    }
+    @java.lang.Override
+    public Builder clearField(
+        com.google.protobuf.Descriptors.FieldDescriptor field) {
+      return super.clearField(field);
+    }
+    @java.lang.Override
+    public Builder clearOneof(
+        com.google.protobuf.Descriptors.OneofDescriptor oneof) {
+      return super.clearOneof(oneof);
+    }
+    @java.lang.Override
+    public Builder setRepeatedField(
+        com.google.protobuf.Descriptors.FieldDescriptor field,
+        int index, java.lang.Object value) {
+      return super.setRepeatedField(field, index, value);
+    }
+    @java.lang.Override
+    public Builder addRepeatedField(
+        com.google.protobuf.Descriptors.FieldDescriptor field,
+        java.lang.Object value) {
+      return super.addRepeatedField(field, value);
+    }
+    @java.lang.Override
+    public Builder mergeFrom(com.google.protobuf.Message other) {
+      if (other instanceof org.tribuo.common.liblinear.protos.LibLinearModelProto) {
+        return mergeFrom((org.tribuo.common.liblinear.protos.LibLinearModelProto)other);
+      } else {
+        super.mergeFrom(other);
+        return this;
+      }
+    }
+
+    public Builder mergeFrom(org.tribuo.common.liblinear.protos.LibLinearModelProto other) {
+      if (other == org.tribuo.common.liblinear.protos.LibLinearModelProto.getDefaultInstance()) return this;
+      if (other.hasMetadata()) {
+        mergeMetadata(other.getMetadata());
+      }
+      if (!other.models_.isEmpty()) {
+        if (models_.isEmpty()) {
+          models_ = other.models_;
+          bitField0_ = (bitField0_ & ~0x00000001);
+        } else {
+          ensureModelsIsMutable();
+          models_.addAll(other.models_);
+        }
+        onChanged();
+      }
+      this.mergeUnknownFields(other.unknownFields);
+      onChanged();
+      return this;
+    }
+
+    @java.lang.Override
+    public final boolean isInitialized() {
+      return true;
+    }
+
+    @java.lang.Override
+    public Builder mergeFrom(
+        com.google.protobuf.CodedInputStream input,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws java.io.IOException {
+      org.tribuo.common.liblinear.protos.LibLinearModelProto parsedMessage = null;
+      try {
+        parsedMessage = PARSER.parsePartialFrom(input, extensionRegistry);
+      } catch (com.google.protobuf.InvalidProtocolBufferException e) {
+        parsedMessage = (org.tribuo.common.liblinear.protos.LibLinearModelProto) e.getUnfinishedMessage();
+        throw e.unwrapIOException();
+      } finally {
+        if (parsedMessage != null) {
+          mergeFrom(parsedMessage);
+        }
+      }
+      return this;
+    }
+    private int bitField0_;
+
+    private org.tribuo.protos.core.ModelDataProto metadata_;
+    private com.google.protobuf.SingleFieldBuilderV3<
+        org.tribuo.protos.core.ModelDataProto, org.tribuo.protos.core.ModelDataProto.Builder, org.tribuo.protos.core.ModelDataProtoOrBuilder> metadataBuilder_;
+    /**
+     * <code>.tribuo.core.ModelDataProto metadata = 1;</code>
+     * @return Whether the metadata field is set.
+     */
+    public boolean hasMetadata() {
+      return metadataBuilder_ != null || metadata_ != null;
+    }
+    /**
+     * <code>.tribuo.core.ModelDataProto metadata = 1;</code>
+     * @return The metadata.
+     */
+    public org.tribuo.protos.core.ModelDataProto getMetadata() {
+      if (metadataBuilder_ == null) {
+        return metadata_ == null ? org.tribuo.protos.core.ModelDataProto.getDefaultInstance() : metadata_;
+      } else {
+        return metadataBuilder_.getMessage();
+      }
+    }
+    /**
+     * <code>.tribuo.core.ModelDataProto metadata = 1;</code>
+     */
+    public Builder setMetadata(org.tribuo.protos.core.ModelDataProto value) {
+      if (metadataBuilder_ == null) {
+        if (value == null) {
+          throw new NullPointerException();
+        }
+        metadata_ = value;
+        onChanged();
+      } else {
+        metadataBuilder_.setMessage(value);
+      }
+
+      return this;
+    }
+    /**
+     * <code>.tribuo.core.ModelDataProto metadata = 1;</code>
+     */
+    public Builder setMetadata(
+        org.tribuo.protos.core.ModelDataProto.Builder builderForValue) {
+      if (metadataBuilder_ == null) {
+        metadata_ = builderForValue.build();
+        onChanged();
+      } else {
+        metadataBuilder_.setMessage(builderForValue.build());
+      }
+
+      return this;
+    }
+    /**
+     * <code>.tribuo.core.ModelDataProto metadata = 1;</code>
+     */
+    public Builder mergeMetadata(org.tribuo.protos.core.ModelDataProto value) {
+      if (metadataBuilder_ == null) {
+        if (metadata_ != null) {
+          metadata_ =
+            org.tribuo.protos.core.ModelDataProto.newBuilder(metadata_).mergeFrom(value).buildPartial();
+        } else {
+          metadata_ = value;
+        }
+        onChanged();
+      } else {
+        metadataBuilder_.mergeFrom(value);
+      }
+
+      return this;
+    }
+    /**
+     * <code>.tribuo.core.ModelDataProto metadata = 1;</code>
+     */
+    public Builder clearMetadata() {
+      if (metadataBuilder_ == null) {
+        metadata_ = null;
+        onChanged();
+      } else {
+        metadata_ = null;
+        metadataBuilder_ = null;
+      }
+
+      return this;
+    }
+    /**
+     * <code>.tribuo.core.ModelDataProto metadata = 1;</code>
+     */
+    public org.tribuo.protos.core.ModelDataProto.Builder getMetadataBuilder() {
+      
+      onChanged();
+      return getMetadataFieldBuilder().getBuilder();
+    }
+    /**
+     * <code>.tribuo.core.ModelDataProto metadata = 1;</code>
+     */
+    public org.tribuo.protos.core.ModelDataProtoOrBuilder getMetadataOrBuilder() {
+      if (metadataBuilder_ != null) {
+        return metadataBuilder_.getMessageOrBuilder();
+      } else {
+        return metadata_ == null ?
+            org.tribuo.protos.core.ModelDataProto.getDefaultInstance() : metadata_;
+      }
+    }
+    /**
+     * <code>.tribuo.core.ModelDataProto metadata = 1;</code>
+     */
+    private com.google.protobuf.SingleFieldBuilderV3<
+        org.tribuo.protos.core.ModelDataProto, org.tribuo.protos.core.ModelDataProto.Builder, org.tribuo.protos.core.ModelDataProtoOrBuilder> 
+        getMetadataFieldBuilder() {
+      if (metadataBuilder_ == null) {
+        metadataBuilder_ = new com.google.protobuf.SingleFieldBuilderV3<
+            org.tribuo.protos.core.ModelDataProto, org.tribuo.protos.core.ModelDataProto.Builder, org.tribuo.protos.core.ModelDataProtoOrBuilder>(
+                getMetadata(),
+                getParentForChildren(),
+                isClean());
+        metadata_ = null;
+      }
+      return metadataBuilder_;
+    }
+
+    private java.util.List<com.google.protobuf.ByteString> models_ = java.util.Collections.emptyList();
+    private void ensureModelsIsMutable() {
+      if (!((bitField0_ & 0x00000001) != 0)) {
+        models_ = new java.util.ArrayList<com.google.protobuf.ByteString>(models_);
+        bitField0_ |= 0x00000001;
+       }
+    }
+    /**
+     * <code>repeated bytes models = 2;</code>
+     * @return A list containing the models.
+     */
+    public java.util.List<com.google.protobuf.ByteString>
+        getModelsList() {
+      return ((bitField0_ & 0x00000001) != 0) ?
+               java.util.Collections.unmodifiableList(models_) : models_;
+    }
+    /**
+     * <code>repeated bytes models = 2;</code>
+     * @return The count of models.
+     */
+    public int getModelsCount() {
+      return models_.size();
+    }
+    /**
+     * <code>repeated bytes models = 2;</code>
+     * @param index The index of the element to return.
+     * @return The models at the given index.
+     */
+    public com.google.protobuf.ByteString getModels(int index) {
+      return models_.get(index);
+    }
+    /**
+     * <code>repeated bytes models = 2;</code>
+     * @param index The index to set the value at.
+     * @param value The models to set.
+     * @return This builder for chaining.
+     */
+    public Builder setModels(
+        int index, com.google.protobuf.ByteString value) {
+      if (value == null) {
+    throw new NullPointerException();
+  }
+  ensureModelsIsMutable();
+      models_.set(index, value);
+      onChanged();
+      return this;
+    }
+    /**
+     * <code>repeated bytes models = 2;</code>
+     * @param value The models to add.
+     * @return This builder for chaining.
+     */
+    public Builder addModels(com.google.protobuf.ByteString value) {
+      if (value == null) {
+    throw new NullPointerException();
+  }
+  ensureModelsIsMutable();
+      models_.add(value);
+      onChanged();
+      return this;
+    }
+    /**
+     * <code>repeated bytes models = 2;</code>
+     * @param values The models to add.
+     * @return This builder for chaining.
+     */
+    public Builder addAllModels(
+        java.lang.Iterable<? extends com.google.protobuf.ByteString> values) {
+      ensureModelsIsMutable();
+      com.google.protobuf.AbstractMessageLite.Builder.addAll(
+          values, models_);
+      onChanged();
+      return this;
+    }
+    /**
+     * <code>repeated bytes models = 2;</code>
+     * @return This builder for chaining.
+     */
+    public Builder clearModels() {
+      models_ = java.util.Collections.emptyList();
+      bitField0_ = (bitField0_ & ~0x00000001);
+      onChanged();
+      return this;
+    }
+    @java.lang.Override
+    public final Builder setUnknownFields(
+        final com.google.protobuf.UnknownFieldSet unknownFields) {
+      return super.setUnknownFields(unknownFields);
+    }
+
+    @java.lang.Override
+    public final Builder mergeUnknownFields(
+        final com.google.protobuf.UnknownFieldSet unknownFields) {
+      return super.mergeUnknownFields(unknownFields);
+    }
+
+
+    // @@protoc_insertion_point(builder_scope:tribuo.common.liblinear.LibLinearModelProto)
+  }
+
+  // @@protoc_insertion_point(class_scope:tribuo.common.liblinear.LibLinearModelProto)
+  private static final org.tribuo.common.liblinear.protos.LibLinearModelProto DEFAULT_INSTANCE;
+  static {
+    DEFAULT_INSTANCE = new org.tribuo.common.liblinear.protos.LibLinearModelProto();
+  }
+
+  public static org.tribuo.common.liblinear.protos.LibLinearModelProto getDefaultInstance() {
+    return DEFAULT_INSTANCE;
+  }
+
+  private static final com.google.protobuf.Parser<LibLinearModelProto>
+      PARSER = new com.google.protobuf.AbstractParser<LibLinearModelProto>() {
+    @java.lang.Override
+    public LibLinearModelProto parsePartialFrom(
+        com.google.protobuf.CodedInputStream input,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws com.google.protobuf.InvalidProtocolBufferException {
+      return new LibLinearModelProto(input, extensionRegistry);
+    }
+  };
+
+  public static com.google.protobuf.Parser<LibLinearModelProto> parser() {
+    return PARSER;
+  }
+
+  @java.lang.Override
+  public com.google.protobuf.Parser<LibLinearModelProto> getParserForType() {
+    return PARSER;
+  }
+
+  @java.lang.Override
+  public org.tribuo.common.liblinear.protos.LibLinearModelProto getDefaultInstanceForType() {
+    return DEFAULT_INSTANCE;
+  }
+
+}
+
diff --git a/Common/LibLinear/src/main/java/org/tribuo/common/liblinear/protos/LibLinearModelProtoOrBuilder.java b/Common/LibLinear/src/main/java/org/tribuo/common/liblinear/protos/LibLinearModelProtoOrBuilder.java
new file mode 100644
index 000000000..2e1b788d7
--- /dev/null
+++ b/Common/LibLinear/src/main/java/org/tribuo/common/liblinear/protos/LibLinearModelProtoOrBuilder.java
@@ -0,0 +1,41 @@
+// Generated by the protocol buffer compiler.  DO NOT EDIT!
+// source: tribuo-liblinear.proto
+
+package org.tribuo.common.liblinear.protos;
+
+public interface LibLinearModelProtoOrBuilder extends
+    // @@protoc_insertion_point(interface_extends:tribuo.common.liblinear.LibLinearModelProto)
+    com.google.protobuf.MessageOrBuilder {
+
+  /**
+   * <code>.tribuo.core.ModelDataProto metadata = 1;</code>
+   * @return Whether the metadata field is set.
+   */
+  boolean hasMetadata();
+  /**
+   * <code>.tribuo.core.ModelDataProto metadata = 1;</code>
+   * @return The metadata.
+   */
+  org.tribuo.protos.core.ModelDataProto getMetadata();
+  /**
+   * <code>.tribuo.core.ModelDataProto metadata = 1;</code>
+   */
+  org.tribuo.protos.core.ModelDataProtoOrBuilder getMetadataOrBuilder();
+
+  /**
+   * <code>repeated bytes models = 2;</code>
+   * @return A list containing the models.
+   */
+  java.util.List<com.google.protobuf.ByteString> getModelsList();
+  /**
+   * <code>repeated bytes models = 2;</code>
+   * @return The count of models.
+   */
+  int getModelsCount();
+  /**
+   * <code>repeated bytes models = 2;</code>
+   * @param index The index of the element to return.
+   * @return The models at the given index.
+   */
+  com.google.protobuf.ByteString getModels(int index);
+}
diff --git a/Common/LibLinear/src/main/java/org/tribuo/common/liblinear/protos/LibLinearProto.java b/Common/LibLinear/src/main/java/org/tribuo/common/liblinear/protos/LibLinearProto.java
new file mode 100644
index 000000000..52b6af4ad
--- /dev/null
+++ b/Common/LibLinear/src/main/java/org/tribuo/common/liblinear/protos/LibLinearProto.java
@@ -0,0 +1,1178 @@
+// Generated by the protocol buffer compiler.  DO NOT EDIT!
+// source: tribuo-liblinear.proto
+
+package org.tribuo.common.liblinear.protos;
+
+/**
+ * <pre>
+ *Liblinear model data proto
+ * </pre>
+ *
+ * Protobuf type {@code tribuo.common.liblinear.LibLinearProto}
+ */
+public final class LibLinearProto extends
+    com.google.protobuf.GeneratedMessageV3 implements
+    // @@protoc_insertion_point(message_implements:tribuo.common.liblinear.LibLinearProto)
+    LibLinearProtoOrBuilder {
+private static final long serialVersionUID = 0L;
+  // Use LibLinearProto.newBuilder() to construct.
+  private LibLinearProto(com.google.protobuf.GeneratedMessageV3.Builder<?> builder) {
+    super(builder);
+  }
+  private LibLinearProto() {
+    label_ = emptyIntList();
+    solverType_ = "";
+    w_ = emptyDoubleList();
+  }
+
+  @java.lang.Override
+  @SuppressWarnings({"unused"})
+  protected java.lang.Object newInstance(
+      UnusedPrivateParameter unused) {
+    return new LibLinearProto();
+  }
+
+  @java.lang.Override
+  public final com.google.protobuf.UnknownFieldSet
+  getUnknownFields() {
+    return this.unknownFields;
+  }
+  private LibLinearProto(
+      com.google.protobuf.CodedInputStream input,
+      com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+      throws com.google.protobuf.InvalidProtocolBufferException {
+    this();
+    if (extensionRegistry == null) {
+      throw new java.lang.NullPointerException();
+    }
+    int mutable_bitField0_ = 0;
+    com.google.protobuf.UnknownFieldSet.Builder unknownFields =
+        com.google.protobuf.UnknownFieldSet.newBuilder();
+    try {
+      boolean done = false;
+      while (!done) {
+        int tag = input.readTag();
+        switch (tag) {
+          case 0:
+            done = true;
+            break;
+          case 9: {
+
+            bias_ = input.readDouble();
+            break;
+          }
+          case 16: {
+            if (!((mutable_bitField0_ & 0x00000001) != 0)) {
+              label_ = newIntList();
+              mutable_bitField0_ |= 0x00000001;
+            }
+            label_.addInt(input.readInt32());
+            break;
+          }
+          case 18: {
+            int length = input.readRawVarint32();
+            int limit = input.pushLimit(length);
+            if (!((mutable_bitField0_ & 0x00000001) != 0) && input.getBytesUntilLimit() > 0) {
+              label_ = newIntList();
+              mutable_bitField0_ |= 0x00000001;
+            }
+            while (input.getBytesUntilLimit() > 0) {
+              label_.addInt(input.readInt32());
+            }
+            input.popLimit(limit);
+            break;
+          }
+          case 24: {
+
+            nrClass_ = input.readInt32();
+            break;
+          }
+          case 32: {
+
+            nrFeature_ = input.readInt32();
+            break;
+          }
+          case 42: {
+            java.lang.String s = input.readStringRequireUtf8();
+
+            solverType_ = s;
+            break;
+          }
+          case 49: {
+            if (!((mutable_bitField0_ & 0x00000002) != 0)) {
+              w_ = newDoubleList();
+              mutable_bitField0_ |= 0x00000002;
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+            w_.addDouble(input.readDouble());
+            break;
+          }
+          case 50: {
+            int length = input.readRawVarint32();
+            int limit = input.pushLimit(length);
+            if (!((mutable_bitField0_ & 0x00000002) != 0) && input.getBytesUntilLimit() > 0) {
+              w_ = newDoubleList();
+              mutable_bitField0_ |= 0x00000002;
+            }
+            while (input.getBytesUntilLimit() > 0) {
+              w_.addDouble(input.readDouble());
+            }
+            input.popLimit(limit);
+            break;
+          }
+          case 57: {
+
+            rho_ = input.readDouble();
+            break;
+          }
+          default: {
+            if (!parseUnknownField(
+                input, unknownFields, extensionRegistry, tag)) {
+              done = true;
+            }
+            break;
+          }
+        }
+      }
+    } catch (com.google.protobuf.InvalidProtocolBufferException e) {
+      throw e.setUnfinishedMessage(this);
+    } catch (java.io.IOException e) {
+      throw new com.google.protobuf.InvalidProtocolBufferException(
+          e).setUnfinishedMessage(this);
+    } finally {
+      if (((mutable_bitField0_ & 0x00000001) != 0)) {
+        label_.makeImmutable(); // C
+      }
+      if (((mutable_bitField0_ & 0x00000002) != 0)) {
+        w_.makeImmutable(); // C
+      }
+      this.unknownFields = unknownFields.build();
+      makeExtensionsImmutable();
+    }
+  }
+  public static final com.google.protobuf.Descriptors.Descriptor
+      getDescriptor() {
+    return org.tribuo.common.liblinear.protos.TribuoLiblinear.internal_static_tribuo_common_liblinear_LibLinearProto_descriptor;
+  }
+
+  @java.lang.Override
+  protected com.google.protobuf.GeneratedMessageV3.FieldAccessorTable
+      internalGetFieldAccessorTable() {
+    return org.tribuo.common.liblinear.protos.TribuoLiblinear.internal_static_tribuo_common_liblinear_LibLinearProto_fieldAccessorTable
+        .ensureFieldAccessorsInitialized(
+            org.tribuo.common.liblinear.protos.LibLinearProto.class, org.tribuo.common.liblinear.protos.LibLinearProto.Builder.class);
+  }
+
+  public static final int BIAS_FIELD_NUMBER = 1;
+  private double bias_;
+  /**
+   * <code>double bias = 1;</code>
+   * @return The bias.
+   */
+  @java.lang.Override
+  public double getBias() {
+    return bias_;
+  }
+
+  public static final int LABEL_FIELD_NUMBER = 2;
+  private com.google.protobuf.Internal.IntList label_;
+  /**
+   * <code>repeated int32 label = 2;</code>
+   * @return A list containing the label.
+   */
+  @java.lang.Override
+  public java.util.List<java.lang.Integer>
+      getLabelList() {
+    return label_;
+  }
+  /**
+   * <code>repeated int32 label = 2;</code>
+   * @return The count of label.
+   */
+  public int getLabelCount() {
+    return label_.size();
+  }
+  /**
+   * <code>repeated int32 label = 2;</code>
+   * @param index The index of the element to return.
+   * @return The label at the given index.
+   */
+  public int getLabel(int index) {
+    return label_.getInt(index);
+  }
+  private int labelMemoizedSerializedSize = -1;
+
+  public static final int NR_CLASS_FIELD_NUMBER = 3;
+  private int nrClass_;
+  /**
+   * <code>int32 nr_class = 3;</code>
+   * @return The nrClass.
+   */
+  @java.lang.Override
+  public int getNrClass() {
+    return nrClass_;
+  }
+
+  public static final int NR_FEATURE_FIELD_NUMBER = 4;
+  private int nrFeature_;
+  /**
+   * <code>int32 nr_feature = 4;</code>
+   * @return The nrFeature.
+   */
+  @java.lang.Override
+  public int getNrFeature() {
+    return nrFeature_;
+  }
+
+  public static final int SOLVER_TYPE_FIELD_NUMBER = 5;
+  private volatile java.lang.Object solverType_;
+  /**
+   * <code>string solver_type = 5;</code>
+   * @return The solverType.
+   */
+  @java.lang.Override
+  public java.lang.String getSolverType() {
+    java.lang.Object ref = solverType_;
+    if (ref instanceof java.lang.String) {
+      return (java.lang.String) ref;
+    } else {
+      com.google.protobuf.ByteString bs = 
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+      java.lang.String s = bs.toStringUtf8();
+      solverType_ = s;
+      return s;
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+  /**
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+   * @return The bytes for solverType.
+   */
+  @java.lang.Override
+  public com.google.protobuf.ByteString
+      getSolverTypeBytes() {
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+    if (ref instanceof java.lang.String) {
+      com.google.protobuf.ByteString b = 
+          com.google.protobuf.ByteString.copyFromUtf8(
+              (java.lang.String) ref);
+      solverType_ = b;
+      return b;
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+  }
+
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+  private com.google.protobuf.Internal.DoubleList w_;
+  /**
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+   * @return A list containing the w.
+   */
+  @java.lang.Override
+  public java.util.List<java.lang.Double>
+      getWList() {
+    return w_;
+  }
+  /**
+   * <code>repeated double w = 6;</code>
+   * @return The count of w.
+   */
+  public int getWCount() {
+    return w_.size();
+  }
+  /**
+   * <code>repeated double w = 6;</code>
+   * @param index The index of the element to return.
+   * @return The w at the given index.
+   */
+  public double getW(int index) {
+    return w_.getDouble(index);
+  }
+  private int wMemoizedSerializedSize = -1;
+
+  public static final int RHO_FIELD_NUMBER = 7;
+  private double rho_;
+  /**
+   * <code>double rho = 7;</code>
+   * @return The rho.
+   */
+  @java.lang.Override
+  public double getRho() {
+    return rho_;
+  }
+
+  private byte memoizedIsInitialized = -1;
+  @java.lang.Override
+  public final boolean isInitialized() {
+    byte isInitialized = memoizedIsInitialized;
+    if (isInitialized == 1) return true;
+    if (isInitialized == 0) return false;
+
+    memoizedIsInitialized = 1;
+    return true;
+  }
+
+  @java.lang.Override
+  public void writeTo(com.google.protobuf.CodedOutputStream output)
+                      throws java.io.IOException {
+    getSerializedSize();
+    if (java.lang.Double.doubleToRawLongBits(bias_) != 0) {
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+    }
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+      output.writeUInt32NoTag(labelMemoizedSerializedSize);
+    }
+    for (int i = 0; i < label_.size(); i++) {
+      output.writeInt32NoTag(label_.getInt(i));
+    }
+    if (nrClass_ != 0) {
+      output.writeInt32(3, nrClass_);
+    }
+    if (nrFeature_ != 0) {
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+    }
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+    }
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+      output.writeUInt32NoTag(50);
+      output.writeUInt32NoTag(wMemoizedSerializedSize);
+    }
+    for (int i = 0; i < w_.size(); i++) {
+      output.writeDoubleNoTag(w_.getDouble(i));
+    }
+    if (java.lang.Double.doubleToRawLongBits(rho_) != 0) {
+      output.writeDouble(7, rho_);
+    }
+    unknownFields.writeTo(output);
+  }
+
+  @java.lang.Override
+  public int getSerializedSize() {
+    int size = memoizedSize;
+    if (size != -1) return size;
+
+    size = 0;
+    if (java.lang.Double.doubleToRawLongBits(bias_) != 0) {
+      size += com.google.protobuf.CodedOutputStream
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+    {
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+      size += dataSize;
+      if (!getLabelList().isEmpty()) {
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+        size += com.google.protobuf.CodedOutputStream
+            .computeInt32SizeNoTag(dataSize);
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+      labelMemoizedSerializedSize = dataSize;
+    }
+    if (nrClass_ != 0) {
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+        .computeInt32Size(3, nrClass_);
+    }
+    if (nrFeature_ != 0) {
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+      if (!getWList().isEmpty()) {
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+        size += com.google.protobuf.CodedOutputStream
+            .computeInt32SizeNoTag(dataSize);
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+      wMemoizedSerializedSize = dataSize;
+    }
+    if (java.lang.Double.doubleToRawLongBits(rho_) != 0) {
+      size += com.google.protobuf.CodedOutputStream
+        .computeDoubleSize(7, rho_);
+    }
+    size += unknownFields.getSerializedSize();
+    memoizedSize = size;
+    return size;
+  }
+
+  @java.lang.Override
+  public boolean equals(final java.lang.Object obj) {
+    if (obj == this) {
+     return true;
+    }
+    if (!(obj instanceof org.tribuo.common.liblinear.protos.LibLinearProto)) {
+      return super.equals(obj);
+    }
+    org.tribuo.common.liblinear.protos.LibLinearProto other = (org.tribuo.common.liblinear.protos.LibLinearProto) obj;
+
+    if (java.lang.Double.doubleToLongBits(getBias())
+        != java.lang.Double.doubleToLongBits(
+            other.getBias())) return false;
+    if (!getLabelList()
+        .equals(other.getLabelList())) return false;
+    if (getNrClass()
+        != other.getNrClass()) return false;
+    if (getNrFeature()
+        != other.getNrFeature()) return false;
+    if (!getSolverType()
+        .equals(other.getSolverType())) return false;
+    if (!getWList()
+        .equals(other.getWList())) return false;
+    if (java.lang.Double.doubleToLongBits(getRho())
+        != java.lang.Double.doubleToLongBits(
+            other.getRho())) return false;
+    if (!unknownFields.equals(other.unknownFields)) return false;
+    return true;
+  }
+
+  @java.lang.Override
+  public int hashCode() {
+    if (memoizedHashCode != 0) {
+      return memoizedHashCode;
+    }
+    int hash = 41;
+    hash = (19 * hash) + getDescriptor().hashCode();
+    hash = (37 * hash) + BIAS_FIELD_NUMBER;
+    hash = (53 * hash) + com.google.protobuf.Internal.hashLong(
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+    if (getLabelCount() > 0) {
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+      hash = (53 * hash) + getLabelList().hashCode();
+    }
+    hash = (37 * hash) + NR_CLASS_FIELD_NUMBER;
+    hash = (53 * hash) + getNrClass();
+    hash = (37 * hash) + NR_FEATURE_FIELD_NUMBER;
+    hash = (53 * hash) + getNrFeature();
+    hash = (37 * hash) + SOLVER_TYPE_FIELD_NUMBER;
+    hash = (53 * hash) + getSolverType().hashCode();
+    if (getWCount() > 0) {
+      hash = (37 * hash) + W_FIELD_NUMBER;
+      hash = (53 * hash) + getWList().hashCode();
+    }
+    hash = (37 * hash) + RHO_FIELD_NUMBER;
+    hash = (53 * hash) + com.google.protobuf.Internal.hashLong(
+        java.lang.Double.doubleToLongBits(getRho()));
+    hash = (29 * hash) + unknownFields.hashCode();
+    memoizedHashCode = hash;
+    return hash;
+  }
+
+  public static org.tribuo.common.liblinear.protos.LibLinearProto parseFrom(
+      java.nio.ByteBuffer data)
+      throws com.google.protobuf.InvalidProtocolBufferException {
+    return PARSER.parseFrom(data);
+  }
+  public static org.tribuo.common.liblinear.protos.LibLinearProto parseFrom(
+      java.nio.ByteBuffer data,
+      com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+      throws com.google.protobuf.InvalidProtocolBufferException {
+    return PARSER.parseFrom(data, extensionRegistry);
+  }
+  public static org.tribuo.common.liblinear.protos.LibLinearProto parseFrom(
+      com.google.protobuf.ByteString data)
+      throws com.google.protobuf.InvalidProtocolBufferException {
+    return PARSER.parseFrom(data);
+  }
+  public static org.tribuo.common.liblinear.protos.LibLinearProto parseFrom(
+      com.google.protobuf.ByteString data,
+      com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+      throws com.google.protobuf.InvalidProtocolBufferException {
+    return PARSER.parseFrom(data, extensionRegistry);
+  }
+  public static org.tribuo.common.liblinear.protos.LibLinearProto parseFrom(byte[] data)
+      throws com.google.protobuf.InvalidProtocolBufferException {
+    return PARSER.parseFrom(data);
+  }
+  public static org.tribuo.common.liblinear.protos.LibLinearProto parseFrom(
+      byte[] data,
+      com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+      throws com.google.protobuf.InvalidProtocolBufferException {
+    return PARSER.parseFrom(data, extensionRegistry);
+  }
+  public static org.tribuo.common.liblinear.protos.LibLinearProto parseFrom(java.io.InputStream input)
+      throws java.io.IOException {
+    return com.google.protobuf.GeneratedMessageV3
+        .parseWithIOException(PARSER, input);
+  }
+  public static org.tribuo.common.liblinear.protos.LibLinearProto parseFrom(
+      java.io.InputStream input,
+      com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+      throws java.io.IOException {
+    return com.google.protobuf.GeneratedMessageV3
+        .parseWithIOException(PARSER, input, extensionRegistry);
+  }
+  public static org.tribuo.common.liblinear.protos.LibLinearProto parseDelimitedFrom(java.io.InputStream input)
+      throws java.io.IOException {
+    return com.google.protobuf.GeneratedMessageV3
+        .parseDelimitedWithIOException(PARSER, input);
+  }
+  public static org.tribuo.common.liblinear.protos.LibLinearProto parseDelimitedFrom(
+      java.io.InputStream input,
+      com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+      throws java.io.IOException {
+    return com.google.protobuf.GeneratedMessageV3
+        .parseDelimitedWithIOException(PARSER, input, extensionRegistry);
+  }
+  public static org.tribuo.common.liblinear.protos.LibLinearProto parseFrom(
+      com.google.protobuf.CodedInputStream input)
+      throws java.io.IOException {
+    return com.google.protobuf.GeneratedMessageV3
+        .parseWithIOException(PARSER, input);
+  }
+  public static org.tribuo.common.liblinear.protos.LibLinearProto parseFrom(
+      com.google.protobuf.CodedInputStream input,
+      com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+      throws java.io.IOException {
+    return com.google.protobuf.GeneratedMessageV3
+        .parseWithIOException(PARSER, input, extensionRegistry);
+  }
+
+  @java.lang.Override
+  public Builder newBuilderForType() { return newBuilder(); }
+  public static Builder newBuilder() {
+    return DEFAULT_INSTANCE.toBuilder();
+  }
+  public static Builder newBuilder(org.tribuo.common.liblinear.protos.LibLinearProto prototype) {
+    return DEFAULT_INSTANCE.toBuilder().mergeFrom(prototype);
+  }
+  @java.lang.Override
+  public Builder toBuilder() {
+    return this == DEFAULT_INSTANCE
+        ? new Builder() : new Builder().mergeFrom(this);
+  }
+
+  @java.lang.Override
+  protected Builder newBuilderForType(
+      com.google.protobuf.GeneratedMessageV3.BuilderParent parent) {
+    Builder builder = new Builder(parent);
+    return builder;
+  }
+  /**
+   * <pre>
+   *Liblinear model data proto
+   * </pre>
+   *
+   * Protobuf type {@code tribuo.common.liblinear.LibLinearProto}
+   */
+  public static final class Builder extends
+      com.google.protobuf.GeneratedMessageV3.Builder<Builder> implements
+      // @@protoc_insertion_point(builder_implements:tribuo.common.liblinear.LibLinearProto)
+      org.tribuo.common.liblinear.protos.LibLinearProtoOrBuilder {
+    public static final com.google.protobuf.Descriptors.Descriptor
+        getDescriptor() {
+      return org.tribuo.common.liblinear.protos.TribuoLiblinear.internal_static_tribuo_common_liblinear_LibLinearProto_descriptor;
+    }
+
+    @java.lang.Override
+    protected com.google.protobuf.GeneratedMessageV3.FieldAccessorTable
+        internalGetFieldAccessorTable() {
+      return org.tribuo.common.liblinear.protos.TribuoLiblinear.internal_static_tribuo_common_liblinear_LibLinearProto_fieldAccessorTable
+          .ensureFieldAccessorsInitialized(
+              org.tribuo.common.liblinear.protos.LibLinearProto.class, org.tribuo.common.liblinear.protos.LibLinearProto.Builder.class);
+    }
+
+    // Construct using org.tribuo.common.liblinear.protos.LibLinearProto.newBuilder()
+    private Builder() {
+      maybeForceBuilderInitialization();
+    }
+
+    private Builder(
+        com.google.protobuf.GeneratedMessageV3.BuilderParent parent) {
+      super(parent);
+      maybeForceBuilderInitialization();
+    }
+    private void maybeForceBuilderInitialization() {
+      if (com.google.protobuf.GeneratedMessageV3
+              .alwaysUseFieldBuilders) {
+      }
+    }
+    @java.lang.Override
+    public Builder clear() {
+      super.clear();
+      bias_ = 0D;
+
+      label_ = emptyIntList();
+      bitField0_ = (bitField0_ & ~0x00000001);
+      nrClass_ = 0;
+
+      nrFeature_ = 0;
+
+      solverType_ = "";
+
+      w_ = emptyDoubleList();
+      bitField0_ = (bitField0_ & ~0x00000002);
+      rho_ = 0D;
+
+      return this;
+    }
+
+    @java.lang.Override
+    public com.google.protobuf.Descriptors.Descriptor
+        getDescriptorForType() {
+      return org.tribuo.common.liblinear.protos.TribuoLiblinear.internal_static_tribuo_common_liblinear_LibLinearProto_descriptor;
+    }
+
+    @java.lang.Override
+    public org.tribuo.common.liblinear.protos.LibLinearProto getDefaultInstanceForType() {
+      return org.tribuo.common.liblinear.protos.LibLinearProto.getDefaultInstance();
+    }
+
+    @java.lang.Override
+    public org.tribuo.common.liblinear.protos.LibLinearProto build() {
+      org.tribuo.common.liblinear.protos.LibLinearProto result = buildPartial();
+      if (!result.isInitialized()) {
+        throw newUninitializedMessageException(result);
+      }
+      return result;
+    }
+
+    @java.lang.Override
+    public org.tribuo.common.liblinear.protos.LibLinearProto buildPartial() {
+      org.tribuo.common.liblinear.protos.LibLinearProto result = new org.tribuo.common.liblinear.protos.LibLinearProto(this);
+      int from_bitField0_ = bitField0_;
+      result.bias_ = bias_;
+      if (((bitField0_ & 0x00000001) != 0)) {
+        label_.makeImmutable();
+        bitField0_ = (bitField0_ & ~0x00000001);
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+      result.label_ = label_;
+      result.nrClass_ = nrClass_;
+      result.nrFeature_ = nrFeature_;
+      result.solverType_ = solverType_;
+      if (((bitField0_ & 0x00000002) != 0)) {
+        w_.makeImmutable();
+        bitField0_ = (bitField0_ & ~0x00000002);
+      }
+      result.w_ = w_;
+      result.rho_ = rho_;
+      onBuilt();
+      return result;
+    }
+
+    @java.lang.Override
+    public Builder clone() {
+      return super.clone();
+    }
+    @java.lang.Override
+    public Builder setField(
+        com.google.protobuf.Descriptors.FieldDescriptor field,
+        java.lang.Object value) {
+      return super.setField(field, value);
+    }
+    @java.lang.Override
+    public Builder clearField(
+        com.google.protobuf.Descriptors.FieldDescriptor field) {
+      return super.clearField(field);
+    }
+    @java.lang.Override
+    public Builder clearOneof(
+        com.google.protobuf.Descriptors.OneofDescriptor oneof) {
+      return super.clearOneof(oneof);
+    }
+    @java.lang.Override
+    public Builder setRepeatedField(
+        com.google.protobuf.Descriptors.FieldDescriptor field,
+        int index, java.lang.Object value) {
+      return super.setRepeatedField(field, index, value);
+    }
+    @java.lang.Override
+    public Builder addRepeatedField(
+        com.google.protobuf.Descriptors.FieldDescriptor field,
+        java.lang.Object value) {
+      return super.addRepeatedField(field, value);
+    }
+    @java.lang.Override
+    public Builder mergeFrom(com.google.protobuf.Message other) {
+      if (other instanceof org.tribuo.common.liblinear.protos.LibLinearProto) {
+        return mergeFrom((org.tribuo.common.liblinear.protos.LibLinearProto)other);
+      } else {
+        super.mergeFrom(other);
+        return this;
+      }
+    }
+
+    public Builder mergeFrom(org.tribuo.common.liblinear.protos.LibLinearProto other) {
+      if (other == org.tribuo.common.liblinear.protos.LibLinearProto.getDefaultInstance()) return this;
+      if (other.getBias() != 0D) {
+        setBias(other.getBias());
+      }
+      if (!other.label_.isEmpty()) {
+        if (label_.isEmpty()) {
+          label_ = other.label_;
+          bitField0_ = (bitField0_ & ~0x00000001);
+        } else {
+          ensureLabelIsMutable();
+          label_.addAll(other.label_);
+        }
+        onChanged();
+      }
+      if (other.getNrClass() != 0) {
+        setNrClass(other.getNrClass());
+      }
+      if (other.getNrFeature() != 0) {
+        setNrFeature(other.getNrFeature());
+      }
+      if (!other.getSolverType().isEmpty()) {
+        solverType_ = other.solverType_;
+        onChanged();
+      }
+      if (!other.w_.isEmpty()) {
+        if (w_.isEmpty()) {
+          w_ = other.w_;
+          bitField0_ = (bitField0_ & ~0x00000002);
+        } else {
+          ensureWIsMutable();
+          w_.addAll(other.w_);
+        }
+        onChanged();
+      }
+      if (other.getRho() != 0D) {
+        setRho(other.getRho());
+      }
+      this.mergeUnknownFields(other.unknownFields);
+      onChanged();
+      return this;
+    }
+
+    @java.lang.Override
+    public final boolean isInitialized() {
+      return true;
+    }
+
+    @java.lang.Override
+    public Builder mergeFrom(
+        com.google.protobuf.CodedInputStream input,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws java.io.IOException {
+      org.tribuo.common.liblinear.protos.LibLinearProto parsedMessage = null;
+      try {
+        parsedMessage = PARSER.parsePartialFrom(input, extensionRegistry);
+      } catch (com.google.protobuf.InvalidProtocolBufferException e) {
+        parsedMessage = (org.tribuo.common.liblinear.protos.LibLinearProto) e.getUnfinishedMessage();
+        throw e.unwrapIOException();
+      } finally {
+        if (parsedMessage != null) {
+          mergeFrom(parsedMessage);
+        }
+      }
+      return this;
+    }
+    private int bitField0_;
+
+    private double bias_ ;
+    /**
+     * <code>double bias = 1;</code>
+     * @return The bias.
+     */
+    @java.lang.Override
+    public double getBias() {
+      return bias_;
+    }
+    /**
+     * <code>double bias = 1;</code>
+     * @param value The bias to set.
+     * @return This builder for chaining.
+     */
+    public Builder setBias(double value) {
+      
+      bias_ = value;
+      onChanged();
+      return this;
+    }
+    /**
+     * <code>double bias = 1;</code>
+     * @return This builder for chaining.
+     */
+    public Builder clearBias() {
+      
+      bias_ = 0D;
+      onChanged();
+      return this;
+    }
+
+    private com.google.protobuf.Internal.IntList label_ = emptyIntList();
+    private void ensureLabelIsMutable() {
+      if (!((bitField0_ & 0x00000001) != 0)) {
+        label_ = mutableCopy(label_);
+        bitField0_ |= 0x00000001;
+       }
+    }
+    /**
+     * <code>repeated int32 label = 2;</code>
+     * @return A list containing the label.
+     */
+    public java.util.List<java.lang.Integer>
+        getLabelList() {
+      return ((bitField0_ & 0x00000001) != 0) ?
+               java.util.Collections.unmodifiableList(label_) : label_;
+    }
+    /**
+     * <code>repeated int32 label = 2;</code>
+     * @return The count of label.
+     */
+    public int getLabelCount() {
+      return label_.size();
+    }
+    /**
+     * <code>repeated int32 label = 2;</code>
+     * @param index The index of the element to return.
+     * @return The label at the given index.
+     */
+    public int getLabel(int index) {
+      return label_.getInt(index);
+    }
+    /**
+     * <code>repeated int32 label = 2;</code>
+     * @param index The index to set the value at.
+     * @param value The label to set.
+     * @return This builder for chaining.
+     */
+    public Builder setLabel(
+        int index, int value) {
+      ensureLabelIsMutable();
+      label_.setInt(index, value);
+      onChanged();
+      return this;
+    }
+    /**
+     * <code>repeated int32 label = 2;</code>
+     * @param value The label to add.
+     * @return This builder for chaining.
+     */
+    public Builder addLabel(int value) {
+      ensureLabelIsMutable();
+      label_.addInt(value);
+      onChanged();
+      return this;
+    }
+    /**
+     * <code>repeated int32 label = 2;</code>
+     * @param values The label to add.
+     * @return This builder for chaining.
+     */
+    public Builder addAllLabel(
+        java.lang.Iterable<? extends java.lang.Integer> values) {
+      ensureLabelIsMutable();
+      com.google.protobuf.AbstractMessageLite.Builder.addAll(
+          values, label_);
+      onChanged();
+      return this;
+    }
+    /**
+     * <code>repeated int32 label = 2;</code>
+     * @return This builder for chaining.
+     */
+    public Builder clearLabel() {
+      label_ = emptyIntList();
+      bitField0_ = (bitField0_ & ~0x00000001);
+      onChanged();
+      return this;
+    }
+
+    private int nrClass_ ;
+    /**
+     * <code>int32 nr_class = 3;</code>
+     * @return The nrClass.
+     */
+    @java.lang.Override
+    public int getNrClass() {
+      return nrClass_;
+    }
+    /**
+     * <code>int32 nr_class = 3;</code>
+     * @param value The nrClass to set.
+     * @return This builder for chaining.
+     */
+    public Builder setNrClass(int value) {
+      
+      nrClass_ = value;
+      onChanged();
+      return this;
+    }
+    /**
+     * <code>int32 nr_class = 3;</code>
+     * @return This builder for chaining.
+     */
+    public Builder clearNrClass() {
+      
+      nrClass_ = 0;
+      onChanged();
+      return this;
+    }
+
+    private int nrFeature_ ;
+    /**
+     * <code>int32 nr_feature = 4;</code>
+     * @return The nrFeature.
+     */
+    @java.lang.Override
+    public int getNrFeature() {
+      return nrFeature_;
+    }
+    /**
+     * <code>int32 nr_feature = 4;</code>
+     * @param value The nrFeature to set.
+     * @return This builder for chaining.
+     */
+    public Builder setNrFeature(int value) {
+      
+      nrFeature_ = value;
+      onChanged();
+      return this;
+    }
+    /**
+     * <code>int32 nr_feature = 4;</code>
+     * @return This builder for chaining.
+     */
+    public Builder clearNrFeature() {
+      
+      nrFeature_ = 0;
+      onChanged();
+      return this;
+    }
+
+    private java.lang.Object solverType_ = "";
+    /**
+     * <code>string solver_type = 5;</code>
+     * @return The solverType.
+     */
+    public java.lang.String getSolverType() {
+      java.lang.Object ref = solverType_;
+      if (!(ref instanceof java.lang.String)) {
+        com.google.protobuf.ByteString bs =
+            (com.google.protobuf.ByteString) ref;
+        java.lang.String s = bs.toStringUtf8();
+        solverType_ = s;
+        return s;
+      } else {
+        return (java.lang.String) ref;
+      }
+    }
+    /**
+     * <code>string solver_type = 5;</code>
+     * @return The bytes for solverType.
+     */
+    public com.google.protobuf.ByteString
+        getSolverTypeBytes() {
+      java.lang.Object ref = solverType_;
+      if (ref instanceof String) {
+        com.google.protobuf.ByteString b = 
+            com.google.protobuf.ByteString.copyFromUtf8(
+                (java.lang.String) ref);
+        solverType_ = b;
+        return b;
+      } else {
+        return (com.google.protobuf.ByteString) ref;
+      }
+    }
+    /**
+     * <code>string solver_type = 5;</code>
+     * @param value The solverType to set.
+     * @return This builder for chaining.
+     */
+    public Builder setSolverType(
+        java.lang.String value) {
+      if (value == null) {
+    throw new NullPointerException();
+  }
+  
+      solverType_ = value;
+      onChanged();
+      return this;
+    }
+    /**
+     * <code>string solver_type = 5;</code>
+     * @return This builder for chaining.
+     */
+    public Builder clearSolverType() {
+      
+      solverType_ = getDefaultInstance().getSolverType();
+      onChanged();
+      return this;
+    }
+    /**
+     * <code>string solver_type = 5;</code>
+     * @param value The bytes for solverType to set.
+     * @return This builder for chaining.
+     */
+    public Builder setSolverTypeBytes(
+        com.google.protobuf.ByteString value) {
+      if (value == null) {
+    throw new NullPointerException();
+  }
+  checkByteStringIsUtf8(value);
+      
+      solverType_ = value;
+      onChanged();
+      return this;
+    }
+
+    private com.google.protobuf.Internal.DoubleList w_ = emptyDoubleList();
+    private void ensureWIsMutable() {
+      if (!((bitField0_ & 0x00000002) != 0)) {
+        w_ = mutableCopy(w_);
+        bitField0_ |= 0x00000002;
+       }
+    }
+    /**
+     * <code>repeated double w = 6;</code>
+     * @return A list containing the w.
+     */
+    public java.util.List<java.lang.Double>
+        getWList() {
+      return ((bitField0_ & 0x00000002) != 0) ?
+               java.util.Collections.unmodifiableList(w_) : w_;
+    }
+    /**
+     * <code>repeated double w = 6;</code>
+     * @return The count of w.
+     */
+    public int getWCount() {
+      return w_.size();
+    }
+    /**
+     * <code>repeated double w = 6;</code>
+     * @param index The index of the element to return.
+     * @return The w at the given index.
+     */
+    public double getW(int index) {
+      return w_.getDouble(index);
+    }
+    /**
+     * <code>repeated double w = 6;</code>
+     * @param index The index to set the value at.
+     * @param value The w to set.
+     * @return This builder for chaining.
+     */
+    public Builder setW(
+        int index, double value) {
+      ensureWIsMutable();
+      w_.setDouble(index, value);
+      onChanged();
+      return this;
+    }
+    /**
+     * <code>repeated double w = 6;</code>
+     * @param value The w to add.
+     * @return This builder for chaining.
+     */
+    public Builder addW(double value) {
+      ensureWIsMutable();
+      w_.addDouble(value);
+      onChanged();
+      return this;
+    }
+    /**
+     * <code>repeated double w = 6;</code>
+     * @param values The w to add.
+     * @return This builder for chaining.
+     */
+    public Builder addAllW(
+        java.lang.Iterable<? extends java.lang.Double> values) {
+      ensureWIsMutable();
+      com.google.protobuf.AbstractMessageLite.Builder.addAll(
+          values, w_);
+      onChanged();
+      return this;
+    }
+    /**
+     * <code>repeated double w = 6;</code>
+     * @return This builder for chaining.
+     */
+    public Builder clearW() {
+      w_ = emptyDoubleList();
+      bitField0_ = (bitField0_ & ~0x00000002);
+      onChanged();
+      return this;
+    }
+
+    private double rho_ ;
+    /**
+     * <code>double rho = 7;</code>
+     * @return The rho.
+     */
+    @java.lang.Override
+    public double getRho() {
+      return rho_;
+    }
+    /**
+     * <code>double rho = 7;</code>
+     * @param value The rho to set.
+     * @return This builder for chaining.
+     */
+    public Builder setRho(double value) {
+      
+      rho_ = value;
+      onChanged();
+      return this;
+    }
+    /**
+     * <code>double rho = 7;</code>
+     * @return This builder for chaining.
+     */
+    public Builder clearRho() {
+      
+      rho_ = 0D;
+      onChanged();
+      return this;
+    }
+    @java.lang.Override
+    public final Builder setUnknownFields(
+        final com.google.protobuf.UnknownFieldSet unknownFields) {
+      return super.setUnknownFields(unknownFields);
+    }
+
+    @java.lang.Override
+    public final Builder mergeUnknownFields(
+        final com.google.protobuf.UnknownFieldSet unknownFields) {
+      return super.mergeUnknownFields(unknownFields);
+    }
+
+
+    // @@protoc_insertion_point(builder_scope:tribuo.common.liblinear.LibLinearProto)
+  }
+
+  // @@protoc_insertion_point(class_scope:tribuo.common.liblinear.LibLinearProto)
+  private static final org.tribuo.common.liblinear.protos.LibLinearProto DEFAULT_INSTANCE;
+  static {
+    DEFAULT_INSTANCE = new org.tribuo.common.liblinear.protos.LibLinearProto();
+  }
+
+  public static org.tribuo.common.liblinear.protos.LibLinearProto getDefaultInstance() {
+    return DEFAULT_INSTANCE;
+  }
+
+  private static final com.google.protobuf.Parser<LibLinearProto>
+      PARSER = new com.google.protobuf.AbstractParser<LibLinearProto>() {
+    @java.lang.Override
+    public LibLinearProto parsePartialFrom(
+        com.google.protobuf.CodedInputStream input,
+        com.google.protobuf.ExtensionRegistryLite extensionRegistry)
+        throws com.google.protobuf.InvalidProtocolBufferException {
+      return new LibLinearProto(input, extensionRegistry);
+    }
+  };
+
+  public static com.google.protobuf.Parser<LibLinearProto> parser() {
+    return PARSER;
+  }
+
+  @java.lang.Override
+  public com.google.protobuf.Parser<LibLinearProto> getParserForType() {
+    return PARSER;
+  }
+
+  @java.lang.Override
+  public org.tribuo.common.liblinear.protos.LibLinearProto getDefaultInstanceForType() {
+    return DEFAULT_INSTANCE;
+  }
+
+}
+
diff --git a/Common/LibLinear/src/main/java/org/tribuo/common/liblinear/protos/LibLinearProtoOrBuilder.java b/Common/LibLinear/src/main/java/org/tribuo/common/liblinear/protos/LibLinearProtoOrBuilder.java
new file mode 100644
index 000000000..17a769c02
--- /dev/null
+++ b/Common/LibLinear/src/main/java/org/tribuo/common/liblinear/protos/LibLinearProtoOrBuilder.java
@@ -0,0 +1,79 @@
+// Generated by the protocol buffer compiler.  DO NOT EDIT!
+// source: tribuo-liblinear.proto
+
+package org.tribuo.common.liblinear.protos;
+
+public interface LibLinearProtoOrBuilder extends
+    // @@protoc_insertion_point(interface_extends:tribuo.common.liblinear.LibLinearProto)
+    com.google.protobuf.MessageOrBuilder {
+
+  /**
+   * <code>double bias = 1;</code>
+   * @return The bias.
+   */
+  double getBias();
+
+  /**
+   * <code>repeated int32 label = 2;</code>
+   * @return A list containing the label.
+   */
+  java.util.List<java.lang.Integer> getLabelList();
+  /**
+   * <code>repeated int32 label = 2;</code>
+   * @return The count of label.
+   */
+  int getLabelCount();
+  /**
+   * <code>repeated int32 label = 2;</code>
+   * @param index The index of the element to return.
+   * @return The label at the given index.
+   */
+  int getLabel(int index);
+
+  /**
+   * <code>int32 nr_class = 3;</code>
+   * @return The nrClass.
+   */
+  int getNrClass();
+
+  /**
+   * <code>int32 nr_feature = 4;</code>
+   * @return The nrFeature.
+   */
+  int getNrFeature();
+
+  /**
+   * <code>string solver_type = 5;</code>
+   * @return The solverType.
+   */
+  java.lang.String getSolverType();
+  /**
+   * <code>string solver_type = 5;</code>
+   * @return The bytes for solverType.
+   */
+  com.google.protobuf.ByteString
+      getSolverTypeBytes();
+
+  /**
+   * <code>repeated double w = 6;</code>
+   * @return A list containing the w.
+   */
+  java.util.List<java.lang.Double> getWList();
+  /**
+   * <code>repeated double w = 6;</code>
+   * @return The count of w.
+   */
+  int getWCount();
+  /**
+   * <code>repeated double w = 6;</code>
+   * @param index The index of the element to return.
+   * @return The w at the given index.
+   */
+  double getW(int index);
+
+  /**
+   * <code>double rho = 7;</code>
+   * @return The rho.
+   */
+  double getRho();
+}
diff --git a/Common/LibLinear/src/main/java/org/tribuo/common/liblinear/protos/TribuoLiblinear.java b/Common/LibLinear/src/main/java/org/tribuo/common/liblinear/protos/TribuoLiblinear.java
new file mode 100644
index 000000000..d93940272
--- /dev/null
+++ b/Common/LibLinear/src/main/java/org/tribuo/common/liblinear/protos/TribuoLiblinear.java
@@ -0,0 +1,67 @@
+// Generated by the protocol buffer compiler.  DO NOT EDIT!
+// source: tribuo-liblinear.proto
+
+package org.tribuo.common.liblinear.protos;
+
+public final class TribuoLiblinear {
+  private TribuoLiblinear() {}
+  public static void registerAllExtensions(
+      com.google.protobuf.ExtensionRegistryLite registry) {
+  }
+
+  public static void registerAllExtensions(
+      com.google.protobuf.ExtensionRegistry registry) {
+    registerAllExtensions(
+        (com.google.protobuf.ExtensionRegistryLite) registry);
+  }
+  static final com.google.protobuf.Descriptors.Descriptor
+    internal_static_tribuo_common_liblinear_LibLinearProto_descriptor;
+  static final 
+    com.google.protobuf.GeneratedMessageV3.FieldAccessorTable
+      internal_static_tribuo_common_liblinear_LibLinearProto_fieldAccessorTable;
+  static final com.google.protobuf.Descriptors.Descriptor
+    internal_static_tribuo_common_liblinear_LibLinearModelProto_descriptor;
+  static final 
+    com.google.protobuf.GeneratedMessageV3.FieldAccessorTable
+      internal_static_tribuo_common_liblinear_LibLinearModelProto_fieldAccessorTable;
+
+  public static com.google.protobuf.Descriptors.FileDescriptor
+      getDescriptor() {
+    return descriptor;
+  }
+  private static  com.google.protobuf.Descriptors.FileDescriptor
+      descriptor;
+  static {
+    java.lang.String[] descriptorData = {
+      "\n\026tribuo-liblinear.proto\022\027tribuo.common." +
+      "liblinear\032\021tribuo-core.proto\"\200\001\n\016LibLine" +
+      "arProto\022\014\n\004bias\030\001 \001(\001\022\r\n\005label\030\002 \003(\005\022\020\n\010" +
+      "nr_class\030\003 \001(\005\022\022\n\nnr_feature\030\004 \001(\005\022\023\n\013so" +
+      "lver_type\030\005 \001(\t\022\t\n\001w\030\006 \003(\001\022\013\n\003rho\030\007 \001(\001\"" +
+      "T\n\023LibLinearModelProto\022-\n\010metadata\030\001 \001(\013" +
+      "2\033.tribuo.core.ModelDataProto\022\016\n\006models\030" +
+      "\002 \003(\014B&\n\"org.tribuo.common.liblinear.pro" +
+      "tosP\001b\006proto3"
+    };
+    descriptor = com.google.protobuf.Descriptors.FileDescriptor
+      .internalBuildGeneratedFileFrom(descriptorData,
+        new com.google.protobuf.Descriptors.FileDescriptor[] {
+          org.tribuo.protos.core.TribuoCore.getDescriptor(),
+        });
+    internal_static_tribuo_common_liblinear_LibLinearProto_descriptor =
+      getDescriptor().getMessageTypes().get(0);
+    internal_static_tribuo_common_liblinear_LibLinearProto_fieldAccessorTable = new
+      com.google.protobuf.GeneratedMessageV3.FieldAccessorTable(
+        internal_static_tribuo_common_liblinear_LibLinearProto_descriptor,
+        new java.lang.String[] { "Bias", "Label", "NrClass", "NrFeature", "SolverType", "W", "Rho", });
+    internal_static_tribuo_common_liblinear_LibLinearModelProto_descriptor =
+      getDescriptor().getMessageTypes().get(1);
+    internal_static_tribuo_common_liblinear_LibLinearModelProto_fieldAccessorTable = new
+      com.google.protobuf.GeneratedMessageV3.FieldAccessorTable(
+        internal_static_tribuo_common_liblinear_LibLinearModelProto_descriptor,
+        new java.lang.String[] { "Metadata", "Models", });
+    org.tribuo.protos.core.TribuoCore.getDescriptor();
+  }
+
+  // @@protoc_insertion_point(outer_class_scope)
+}
diff --git a/Common/LibLinear/src/main/resources/protos/tribuo-liblinear.proto b/Common/LibLinear/src/main/resources/protos/tribuo-liblinear.proto
new file mode 100644
index 000000000..5c3bacad0
--- /dev/null
+++ b/Common/LibLinear/src/main/resources/protos/tribuo-liblinear.proto
@@ -0,0 +1,49 @@
+/*
+ * Copyright (c) 2022, Oracle and/or its affiliates. All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+syntax = "proto3";
+
+/*
+ * Protos for serializing Tribuo's liblinear wrapper.
+ */
+package tribuo.common.liblinear;
+
+option java_multiple_files = true;
+option java_package = "org.tribuo.common.liblinear.protos";
+
+// Import Tribuo's core protos
+import "tribuo-core.proto";
+
+/*
+Liblinear model data proto
+ */
+message LibLinearProto {
+  double bias = 1;
+  repeated int32 label = 2;
+  int32 nr_class = 3;
+  int32 nr_feature = 4;
+  string solver_type = 5;
+  repeated double w = 6;
+  double rho = 7;
+}
+
+/*
+LibLinearModel proto
+ */
+message LibLinearModelProto {
+  tribuo.core.ModelDataProto metadata = 1;
+  repeated bytes models = 2;
+}
diff --git a/Regression/LibLinear/src/main/java/org/tribuo/regression/liblinear/LibLinearRegressionModel.java b/Regression/LibLinear/src/main/java/org/tribuo/regression/liblinear/LibLinearRegressionModel.java
index b9fc27d21..a2453ff8c 100644
--- a/Regression/LibLinear/src/main/java/org/tribuo/regression/liblinear/LibLinearRegressionModel.java
+++ b/Regression/LibLinear/src/main/java/org/tribuo/regression/liblinear/LibLinearRegressionModel.java
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2015-2021, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2015, 2022, Oracle and/or its affiliates. All rights reserved.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -17,6 +17,9 @@
 package org.tribuo.regression.liblinear;
 
 import ai.onnx.proto.OnnxMl;
+import com.google.protobuf.Any;
+import com.google.protobuf.ByteString;
+import com.google.protobuf.InvalidProtocolBufferException;
 import com.oracle.labs.mlrg.olcut.util.Pair;
 import de.bwaldvogel.liblinear.FeatureNode;
 import de.bwaldvogel.liblinear.Linear;
@@ -30,6 +33,8 @@
 import org.tribuo.Prediction;
 import org.tribuo.common.liblinear.LibLinearModel;
 import org.tribuo.common.liblinear.LibLinearTrainer;
+import org.tribuo.common.liblinear.protos.LibLinearModelProto;
+import org.tribuo.impl.ModelDataCarrier;
 import org.tribuo.provenance.ModelProvenance;
 import org.tribuo.regression.ImmutableRegressionInfo;
 import org.tribuo.regression.Regressor;
@@ -40,7 +45,9 @@
 import org.tribuo.util.onnx.ONNXPlaceholder;
 import org.tribuo.util.onnx.ONNXRef;
 
+import java.io.ByteArrayInputStream;
 import java.io.IOException;
+import java.io.ObjectInputStream;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collections;
@@ -87,6 +94,46 @@ public class LibLinearRegressionModel extends LibLinearModel<Regressor> implemen
         this.mapping = ((ImmutableRegressionInfo) outputInfo).getIDtoNaturalOrderMapping();
     }
 
+    /**
+     * Deserialization factory.
+     * @param version The serialized object version.
+     * @param className The class name.
+     * @param message The serialized data.
+     */
+    public static LibLinearRegressionModel deserializeFromProto(int version, String className, Any message) throws InvalidProtocolBufferException {
+        if (version < 0 || version > CURRENT_VERSION) {
+            throw new IllegalArgumentException("Unknown version " + version + ", this class supports at most version " + CURRENT_VERSION);
+        }
+        if (!"org.tribuo.regression.liblinear.LibLinearRegressionModel".equals(className)) {
+            throw new IllegalStateException("Invalid protobuf, this class can only deserialize LibLinearRegressionModel");
+        }
+        LibLinearModelProto proto = message.unpack(LibLinearModelProto.class);
+
+        ModelDataCarrier<?> carrier = ModelDataCarrier.deserialize(proto.getMetadata());
+        if (!carrier.outputDomain().getOutput(0).getClass().equals(Regressor.class)) {
+            throw new IllegalStateException("Invalid protobuf, output domain is not a regression domain, found " + carrier.outputDomain().getClass());
+        }
+        @SuppressWarnings("unchecked") // guarded by getClass
+        ImmutableOutputInfo<Regressor> outputDomain = (ImmutableOutputInfo<Regressor>) carrier.outputDomain();
+
+        if (proto.getModelsCount() != outputDomain.size()) {
+            throw new IllegalStateException("Invalid protobuf, expected " + outputDomain.size() + " model, found " + proto.getModelsCount());
+        }
+        try {
+            List<de.bwaldvogel.liblinear.Model> models = new ArrayList<>();
+            for (ByteString modelArray : proto.getModelsList()) {
+                ByteArrayInputStream bais = new ByteArrayInputStream(modelArray.toByteArray());
+                ObjectInputStream ois = new ObjectInputStream(bais);
+                de.bwaldvogel.liblinear.Model model = (de.bwaldvogel.liblinear.Model) ois.readObject();
+                ois.close();
+                models.add(model);
+            }
+            return new LibLinearRegressionModel(carrier.name(),carrier.provenance(),carrier.featureDomain(),outputDomain,Collections.unmodifiableList(models));
+        } catch (IOException | ClassNotFoundException e) {
+            throw new IllegalStateException("Invalid protobuf, failed to deserialize liblinear model", e);
+        }
+    }
+
     @Override
     public Prediction<Regressor> predict(Example<Regressor> example) {
         FeatureNode[] features = LibLinearTrainer.exampleToNodes(example, featureIDMap, null);
diff --git a/Regression/LibLinear/src/test/java/org/tribuo/regression/liblinear/TestLibLinear.java b/Regression/LibLinear/src/test/java/org/tribuo/regression/liblinear/TestLibLinear.java
index bb228c93e..08d1b79fd 100644
--- a/Regression/LibLinear/src/test/java/org/tribuo/regression/liblinear/TestLibLinear.java
+++ b/Regression/LibLinear/src/test/java/org/tribuo/regression/liblinear/TestLibLinear.java
@@ -67,7 +67,8 @@ public static Model<Regressor> testLibLinear(Pair<Dataset<Regressor>,Dataset<Reg
     public void testDenseData() {
         Pair<Dataset<Regressor>,Dataset<Regressor>> p = RegressionDataGenerator.denseTrainTest();
         Model<Regressor> model = testLibLinear(p);
-        Helpers.testModelSerialization(model,Regressor.class);
+        Helpers.testModelSerialization(model, Regressor.class);
+        Helpers.testModelProtoSerialization(model, Regressor.class, p.getB());
     }
 
     @Test