ripleyb · May 15, 2026 · Oct 31, 2025 · Feb 6, 2026 · Feb 9, 2026 · Feb 11, 2026
diff --git a/.gitignore b/.gitignore
@@ -80,3 +80,6 @@ gradlew.bat
 Development/gradle/wrapper/gradle-wrapper.properties
 Core/gradle/wrapper/gradle-wrapper.jar
 Core/gradle/wrapper/gradle-wrapper.jar
+/Development/target
+/Abstractions/target
+/docs/digitaltwin-core-docs/target
diff --git a/Core/.gitattributes → Abstractions/.gitattributes b/Core/.gitattributes → Abstractions/.gitattributes
diff --git a/Core/.gitignore → Abstractions/.gitignore b/Core/.gitignore → Abstractions/.gitignore
diff --git a/Core/LICENSE → Abstractions/LICENSE b/Core/LICENSE → Abstractions/LICENSE
diff --git a/Abstractions/README.md b/Abstractions/README.md
@@ -0,0 +1,10 @@
+# ScaleOut Digital Twins&trade; Abstractions Libraries for Java
+
+The open source (Apache 2.0 licensed) project for the digitaltwin-abstractions API:
+
+- [com.scaleoutsoftware.digitaltwin:digitaltwin-abstractions](https://mvnrepository.com/artifact/com.scaleoutsoftware.digitaltwin/digitaltwin-abstractions/3.0.0): Abstract datatypes required for building Digital Twin models.
+
+
+## Documentation
+- [Class reference](https://scaleoutsoftware.github.io/JavaDigitalTwinCore/)
+- [ScaleOut Digital Twins&trade; User Guide](https://static.scaleoutsoftware.com/docs/digital_twin_user_guide/index.html)
diff --git a/Abstractions/build.bat b/Abstractions/build.bat
@@ -0,0 +1,8 @@
+rem ********************
+rem *   Requirements   * 
+rem ********************
+rem * Java JDK 8
+rem * MVN 3.x
+SET JAVA_HOME=C:\path\to\java8
+SET MVN_HOME=C:\path\to\maven
+call mvn clean package install javadoc:jar source:jar
diff --git a/Abstractions/build.sh b/Abstractions/build.sh
@@ -0,0 +1,7 @@
+#!/usr/bin/env sh
+export JAVA_HOME="/path/to/java8"
+export MVN_HOME="/path/to/maven"
+
+export PATH="$JAVA_HOME/bin:$MVN_HOME/bin:$PATH"
+
+mvn clean package install javadoc:jar source:jar
diff --git a/Abstractions/pom.xml b/Abstractions/pom.xml
@@ -0,0 +1,30 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+
+    <groupId>com.scaleoutsoftware.digitaltwin</groupId>
+    <artifactId>digitaltwin-abstractions</artifactId>
+    <version>3.0.0</version>
+
+    <properties>
+        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+    </properties>
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-compiler-plugin</artifactId>
+                <version>3.11.0</version>
+                <configuration>
+                    <proc>none</proc>
+                    <showWarnings>true</showWarnings>
+                    <compilerArgs>
+                        <arg>-Xlint:all</arg>
+                    </compilerArgs>
+                </configuration>
+            </plugin>
+        </plugins>
+    </build>
+</project>
diff --git a/...ftware/digitaltwin/core/AlertMessage.java → ...igitaltwin/abstractions/AlertMessage.java b/...ftware/digitaltwin/core/AlertMessage.java → ...igitaltwin/abstractions/AlertMessage.java
@@ -1,5 +1,5 @@
 /*
- Copyright (c) 2025 by ScaleOut Software, Inc.
+ Copyright (c) 2026 by ScaleOut Software, Inc.
 
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
@@ -13,7 +13,7 @@
  See the License for the specific language governing permissions and
  limitations under the License.
 */
-package com.scaleoutsoftware.digitaltwin.core;
+package com.scaleoutsoftware.digitaltwin.abstractions;
 
 import java.util.HashMap;
 
@@ -26,7 +26,7 @@ public class AlertMessage {
     private final String                    _message;
     private final HashMap<String,String>    _optionalTwinInstanceProperties;
 
-    private AlertMessage() {_title = _severity = _message = null; _optionalTwinInstanceProperties = null;}
+    private AlertMessage() { _title = _severity = _message = null; _optionalTwinInstanceProperties = null;}
 
     /**
      * Construct an alert message with a title, severity, and custom message.

diff --git a/...digitaltwin/core/PersistenceProvider.java → ...stractions/AzureDigitalTwinsProvider.java b/...digitaltwin/core/PersistenceProvider.java → ...stractions/AzureDigitalTwinsProvider.java
@@ -1,5 +1,5 @@
 /*
- Copyright (c) 2025 by ScaleOut Software, Inc.
+ Copyright (c) 2026 by ScaleOut Software, Inc.
 
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
@@ -13,7 +13,7 @@
  See the License for the specific language governing permissions and
  limitations under the License.
 */
-package com.scaleoutsoftware.digitaltwin.core;
+package com.scaleoutsoftware.digitaltwin.abstractions;
 
 import java.util.List;
 import java.util.Map;
@@ -22,20 +22,14 @@
 /**
  * An interface that can be used for persisting/retrieving the state of real-time digital twins.
  */
-public interface PersistenceProvider {
+public interface AzureDigitalTwinsProvider {
 
     /**
      * Returns true if this PersistenceProvider is active, false otherwise.
      * @return true if this PersistenceProvider is active, false otherwise.
      */
     public abstract boolean isActive();
 
-    /**
-     * Retrieves this persistence providers type. Currently supported provider types: AzureDigitalTwins.
-     * @return the persistence provider type.
-     */
-    public PersistenceProviderType getProviderType();
-
     /**
      * Retrieves a future that when complete will return the instance IDs stored in a container, or an empty list if no instances exist.
      * @param containerName the container name.
@@ -121,42 +115,4 @@ public interface PersistenceProvider {
      * @return the property or null if the property does not exist.
      */
     public <T> T getProperty(String containerName, String instanceId, String propertyName, Class<T> clazz);
-
-    /**
-     * Retrieves a future that will complete exceptionally or return void if the RTDT's property was successfully updated.
-     * Updates a RTDT property for the provided instance id specified by the property name and property value.
-     * @param instanceId the instance id.
-     * @param propertyName the property name.
-     * @param propertyValue the property value.
-     * @return a future that will complete exceptionally or return void.
-     */
-    public CompletableFuture<Void> updateRtdtPropertyAsync(String instanceId, String propertyName, Object propertyValue);
-
-    /**
-     * Updates a RTDT property for the provided instance id specified by the property name and property value.
-     * @param instanceId the instance id.
-     * @param propertyName the property name.
-     * @param propertyValue the property value.
-     */
-    public void updateRtdtProperty(String instanceId, String propertyName, Object propertyValue);
-
-    /**
-     * Retrieves a future that will return a property value for a RTDT instance or null if the property doesn't exist.
-     * @param instanceId the instance id.
-     * @param propertyName the property name.
-     * @param clazz the class of the property type
-     * @param <T> the type of the property to return.
-     * @return a future that will return a property value for a RTDT instance.
-     */
-    public <T> CompletableFuture<T> getRtdtPropertyAsync(String instanceId, String propertyName, Class<T> clazz);
-
-    /**
-     * Retrieves a property for a RTDT instance or null if the property does not exist.
-     * @param instanceId the instance id.
-     * @param propertyName the property name.
-     * @param clazz the class of the property type.
-     * @param <T> the type of the property to return.
-     * @return the property value.
-     */
-    public <T> T getRtdtProperty(String instanceId, String propertyName, Class<T> clazz);
 }
diff --git a/...igitaltwin/core/CacheOperationStatus.java → ...in/abstractions/CacheOperationStatus.java b/...igitaltwin/core/CacheOperationStatus.java → ...in/abstractions/CacheOperationStatus.java
@@ -1,5 +1,5 @@
 /*
- Copyright (c) 2025 by ScaleOut Software, Inc.
+ Copyright (c) 2026 by ScaleOut Software, Inc.
 
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
@@ -13,7 +13,7 @@
  See the License for the specific language governing permissions and
  limitations under the License.
 */
-package com.scaleoutsoftware.digitaltwin.core;
+package com.scaleoutsoftware.digitaltwin.abstractions;
 
 /**
  * Status of a cache operation.

diff --git a/...oftware/digitaltwin/core/CacheResult.java → ...digitaltwin/abstractions/CacheResult.java b/...oftware/digitaltwin/core/CacheResult.java → ...digitaltwin/abstractions/CacheResult.java
@@ -1,5 +1,5 @@
 /*
- Copyright (c) 2025 by ScaleOut Software, Inc.
+ Copyright (c) 2026 by ScaleOut Software, Inc.
 
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
@@ -13,7 +13,7 @@
  See the License for the specific language governing permissions and
  limitations under the License.
 */
-package com.scaleoutsoftware.digitaltwin.core;
+package com.scaleoutsoftware.digitaltwin.abstractions;
 
 /**
  * Represents a response from a {@link SharedData} operation.

diff --git a/...re/digitaltwin/core/ProcessingResult.java → ...igitaltwin/abstractions/CreateResult.java b/...re/digitaltwin/core/ProcessingResult.java → ...igitaltwin/abstractions/CreateResult.java
@@ -1,5 +1,5 @@
 /*
- Copyright (c) 2025 by ScaleOut Software, Inc.
+ Copyright (c) 2026 by ScaleOut Software, Inc.
 
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
@@ -13,18 +13,18 @@
  See the License for the specific language governing permissions and
  limitations under the License.
 */
-package com.scaleoutsoftware.digitaltwin.core;
+package com.scaleoutsoftware.digitaltwin.abstractions;
 
 /**
- * The result from a message processor which indicates to update the state object or to ignore
+ * Enum indicating the status of a delete operation.
  */
-public enum ProcessingResult {
+public enum CreateResult {
     /**
-     * Update the digital twin.
+     * The twin instance was successfully created.
      */
-    UpdateDigitalTwin,
+    Success,
     /**
-     * Do not update the digital twin.
+     * The twin instance already existed and could not be created.
      */
-    NoUpdate
+    ObjectExists
 }
diff --git a/...tsoftware/digitaltwin/core/TimerType.java → ...igitaltwin/abstractions/DeleteResult.java b/...tsoftware/digitaltwin/core/TimerType.java → ...igitaltwin/abstractions/DeleteResult.java
@@ -1,5 +1,5 @@
 /*
- Copyright (c) 2025 by ScaleOut Software, Inc.
+ Copyright (c) 2026 by ScaleOut Software, Inc.
 
  Licensed under the Apache License, Version 2.0 (the "License");
  you may not use this file except in compliance with the License.
@@ -13,18 +13,18 @@
  See the License for the specific language governing permissions and
  limitations under the License.
 */
-package com.scaleoutsoftware.digitaltwin.core;
+package com.scaleoutsoftware.digitaltwin.abstractions;
 
 /**
- * Enum representation of the available timer types
+ * Enum indicating the status of a delete operation.
  */
-public enum TimerType {
+public enum DeleteResult {
     /**
-     * This timer should reoccur on a schedule.
+     * The twin instance was successfully deleted.
      */
-    Recurring,
+    Success,
     /**
-     * This timer should trigger one time.
+     * The target twin instance was not found.
      */
-    OneTime
+    NotFound
 }
diff --git a/...ractions/src/main/java/com/scaleoutsoftware/digitaltwin/abstractions/DigitalTwinBase.java b/...ractions/src/main/java/com/scaleoutsoftware/digitaltwin/abstractions/DigitalTwinBase.java
@@ -0,0 +1,121 @@
+/*
+ Copyright (c) 2026 by ScaleOut Software, Inc.
+
+ 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 or implied.
+ See the License for the specific language governing permissions and
+ limitations under the License.
+*/
+package com.scaleoutsoftware.digitaltwin.abstractions;
+
+import java.util.Date;
+import java.util.HashMap;
+
+/**
+ * A real-time digital twin of a data source. The implementation of the real-time DigitalTwin should have a parameterless constructor for
+ * basic initialization.
+ */
+public abstract class DigitalTwinBase<T extends DigitalTwinBase<T>> {
+
+    /* capitalized to match .NET serialization */
+    /**
+     * The identifier for this twin instance
+     */
+    public String Id = "";
+
+    /**
+     * The model this twin instance belongs to.
+     */
+    public String Model = "";
+
+    /**
+     * DO NOT MODIFY. This property is managed by the service. Used to send messages to the instances data source.
+     */
+    public int SourceNamespaceAppId;
+
+    /**
+     * DO NOT MODIFY. This property is managed by the service. Used to store the instances next simulation time; managed by the
+     * service in case of load balancing or server failures.
+     */
+    public long NextSimulationTimeUnixMsec;
+
+    /**
+     * Default constructor.
+     */
+    public DigitalTwinBase() {}
+
+    /**
+     * The identifier of this DigitalTwin.
+     * @return the identifier of this digital twin
+     */
+    public String getId() {
+        return Id;
+    }
+
+    /**
+     * The model for this DigitalTwin.
+     * @return the model for this DigitalTwin
+     */
+    public String getModel() {
+        return Model;
+    }
+
+    /**
+     * INTERNAL: DO NOT MODIFY. This property is managed by the service.
+     *
+     * Used for sending messages back to the instances data source.
+     *
+     * @return the source App ID namespace
+     */
+    public int getSourceAppIdNamespace() {
+        return SourceNamespaceAppId;
+    }
+
+    /**
+     * INTERNAL: DO NOT MODIFY. This property is managed by the service.
+     * @param sourceAppIdNamespace assign this instance a new source app ID namespace.
+     */
+    public void setSourceAppIdNamespace(int sourceAppIdNamespace) {
+        SourceNamespaceAppId = sourceAppIdNamespace;
+    }
+
+    /**
+     * INTERNAL: DO NOT MODIFY. This property is managed by the service.
+     *
+     * Retrieve the next simulation time for this instance.
+     *
+     * @return the next simulation time for this instance.
+     */
+    public long getNextSimulationTimeUnixMsec() {
+        return NextSimulationTimeUnixMsec;
+    }
+
+    /**
+     * INTERNAL: DO NOT MODIFY. This property is managed by the service.
+     *
+     * Assign this instance the next simulation time when the instance will be run.
+     *
+     * @param nextSimulationTimeUnixMsec the next simulation time when the instance will be run.
+     */
+    public void setNextSimulationTimeUnixMsec(long nextSimulationTimeUnixMsec) {
+        NextSimulationTimeUnixMsec = nextSimulationTimeUnixMsec;
+    }
+
+    /**
+     * Initialization method to set the identifier and model for a DigitalTwin instance. Optionally use the
+     * {@link InitContext} to start a timer.
+     * @param context the initialization context.
+     * @throws IllegalStateException if init is called after initialization.
+     */
+    public void init(InitContext<T> context) throws IllegalStateException {
+        this.Id     = context.getId();
+        this.Model  = context.getModel();
+    }
+}