diff --git a/CHANGELOG.md b/CHANGELOG.md
index 0f9b20ea..05efa075 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,6 +5,10 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](http://keepachangelog.com/)
 and this project adheres to [Semantic Versioning](http://semver.org/).
 
+## [Unreleased]
+
+### Added 
+- Add retrofit information to the mapping set class [#252](https://github.com/IN-CORE/incore-services/issues/252)
 
 ## [1.24.0] - 2024-02-07
 
diff --git a/server/dfr3-service/src/main/java/edu/illinois/ncsa/incore/service/dfr3/models/MappingEntryKey.java b/server/dfr3-service/src/main/java/edu/illinois/ncsa/incore/service/dfr3/models/MappingEntryKey.java
new file mode 100644
index 00000000..a9e3f35a
--- /dev/null
+++ b/server/dfr3-service/src/main/java/edu/illinois/ncsa/incore/service/dfr3/models/MappingEntryKey.java
@@ -0,0 +1,57 @@
+/*******************************************************************************
+ * Copyright (c) 2024 University of Illinois and others.  All rights reserved.
+ * This program and the accompanying materials are made available under the
+ * terms of the Mozilla Public License v2.0 which accompanies this distribution,
+ * and is available at https://www.mozilla.org/en-US/MPL/2.0/
+ *
+ * Contributors:
+ * Chen Wang
+ */
+
+package edu.illinois.ncsa.incore.service.dfr3.models;
+
+import com.fasterxml.jackson.annotation.JsonProperty;
+import dev.morphia.annotations.Embedded;
+
+@Embedded
+public class MappingEntryKey {
+    private String name;
+    private String description;
+    private Boolean defaultKey;
+
+    @JsonProperty("config")
+    private MappingEntryKeyConfig config;
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    public String getDescription(){
+        return description;
+    }
+
+    public void setDescription(String description){
+        this.description = description;
+    }
+
+    public Boolean getDefaultKey(){
+        return defaultKey;
+    }
+
+    public void setDefaultKey(Boolean defaultKey){
+        this.defaultKey = defaultKey;
+    }
+
+    public MappingEntryKeyConfig getConfig(){
+        return config;
+    }
+
+    public void setConfig(MappingEntryKeyConfig config){
+        this.config = config;
+    }
+
+}
diff --git a/server/dfr3-service/src/main/java/edu/illinois/ncsa/incore/service/dfr3/models/MappingEntryKeyConfig.java b/server/dfr3-service/src/main/java/edu/illinois/ncsa/incore/service/dfr3/models/MappingEntryKeyConfig.java
new file mode 100644
index 00000000..0b51ae00
--- /dev/null
+++ b/server/dfr3-service/src/main/java/edu/illinois/ncsa/incore/service/dfr3/models/MappingEntryKeyConfig.java
@@ -0,0 +1,53 @@
+/*******************************************************************************
+ * Copyright (c) 2024 University of Illinois and others.  All rights reserved.
+ * This program and the accompanying materials are made available under the
+ * terms of the Mozilla Public License v2.0 which accompanies this distribution,
+ * and is available at https://www.mozilla.org/en-US/MPL/2.0/
+ *
+ * Contributors:
+ * Chen Wang
+ */
+
+package edu.illinois.ncsa.incore.service.dfr3.models;
+
+import dev.morphia.annotations.Embedded;
+
+@Embedded
+public class MappingEntryKeyConfig {
+    private String unit;
+    private String type;
+    private String targetColumn;
+    private String expression;
+
+    public String getUnit(){
+        return unit;
+    }
+
+    public void setUnit(String unit){
+        this.unit = unit;
+    }
+
+    public String getType(){
+        return type;
+    }
+
+    public void setType(String type){
+        this.type = type;
+    }
+
+    public String getTargetColumn(){
+        return targetColumn;
+    }
+
+    public void setTargetColumn(String targetColumn){
+        this.targetColumn = targetColumn;
+    }
+
+    public String getExpression(){
+        return expression;
+    }
+
+    public void setExpression(String expression){
+        this.expression = expression;
+    }
+}
diff --git a/server/dfr3-service/src/main/java/edu/illinois/ncsa/incore/service/dfr3/models/MappingSet.java b/server/dfr3-service/src/main/java/edu/illinois/ncsa/incore/service/dfr3/models/MappingSet.java
index a2950bc1..6ab40b35 100644
--- a/server/dfr3-service/src/main/java/edu/illinois/ncsa/incore/service/dfr3/models/MappingSet.java
+++ b/server/dfr3-service/src/main/java/edu/illinois/ncsa/incore/service/dfr3/models/MappingSet.java
@@ -39,6 +39,8 @@ public class MappingSet {
     private String creator;
     private String owner;
 
+    private MappingEntryKey[] mappingEntryKeys;
+
     /**
      * spaces the object belongs to. Calculated at runtime.
      */
@@ -96,4 +98,12 @@ public String getMappingType() {
     public void setMappingType(String mappingType) {
         this.mappingType = mappingType;
     }
+
+    public MappingEntryKey[] getMappingEntryKeys() {
+        return mappingEntryKeys;
+    }
+
+    public void setRetrofitDefinitions(MappingEntryKey[] mappingEntryKeys) {
+        this.mappingEntryKeys = mappingEntryKeys;
+    }
 }