Adding policy-model, model-api & engine-model

Change-Id: I56702b8f0953457d493f894d155b2a6ddc87b10c
Issue-ID: POLICY-856
Signed-off-by: waqas.ikram <waqas.ikram@ericsson.com>

15 files changed, 7059 insertions, 0 deletions

diff --git a/model/model-api/src/main/java/org/onap/policy/apex/model/modelapi/ApexAPIResult.java b/model/model-api/src/main/java/org/onap/policy/apex/model/modelapi/ApexAPIResult.java
new file mode 100644
index 000000000..2e4328fc5
--- /dev/null
+++ b/model/model-api/src/main/java/org/onap/policy/apex/model/modelapi/ApexAPIResult.java
@@ -0,0 +1,284 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2016-2018 Ericsson. 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 or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * 
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.model.modelapi;
+
+import java.io.PrintWriter;
+import java.io.StringWriter;
+import java.util.ArrayList;
+import java.util.List;
+
+import javax.xml.bind.annotation.XmlAccessType;
+import javax.xml.bind.annotation.XmlAccessorType;
+import javax.xml.bind.annotation.XmlAttribute;
+import javax.xml.bind.annotation.XmlElement;
+import javax.xml.bind.annotation.XmlElementWrapper;
+import javax.xml.bind.annotation.XmlEnum;
+import javax.xml.bind.annotation.XmlRootElement;
+
+/**
+ * The Class ApexEditorAPIResult return the result of and messages from all model API method calls
+ * on the {@link ApexModel} API.
+ */
+@XmlRootElement
+@XmlAccessorType(XmlAccessType.NONE)
+public class ApexAPIResult {
+
+    /**
+     * This enumeration is used to represent the result status of a call on the {@link ApexModel}
+     * API.
+     */
+    @XmlEnum(value = String.class)
+    public enum RESULT {
+        /** The method call succeeded. */
+        SUCCESS,
+        /** The method call succeeded and all operations are now completed. */
+        FINISHED,
+        /** The method call for a create operation failed because the concept already exists. */
+        CONCEPT_EXISTS,
+        /**
+         * The method call for a create operation failed because multiple concepts already exists.
+         */
+        MULTIPLE_CONCEPTS_EXIST,
+        /** The method call on a concept failed because the referenced concept does not exist. */
+        CONCEPT_DOES_NOT_EXIST,
+        /** The method call failed because no action was specified on the method call. */
+        NO_ACTION_SPECIFIED,
+        /**
+         * The method call failed because of a structural error, a missing reference, or other error
+         * on the model.
+         */
+        FAILED,
+        /**
+         * The method call failed for another reason such as the method call is not implemented yet
+         * on the concept on which it was called.
+         */
+        OTHER_ERROR
+    }
+
+    private RESULT result;
+    private List<String> messages = new ArrayList<>();
+
+    /**
+     * The Default Constructor creates a result for a successful operation with no messages.
+     */
+    public ApexAPIResult() {
+        result = RESULT.SUCCESS;
+    }
+
+    /**
+     * This Constructor creates a result with the given result status with no messages.
+     *
+     * @param result the result status to use on this result
+     */
+    public ApexAPIResult(final RESULT result) {
+        this.result = result;
+    }
+
+    /**
+     * This Constructor creates a result with the given result status and message.
+     *
+     * @param result the result status to use on this result
+     * @param message the message to return with the result
+     */
+    public ApexAPIResult(final RESULT result, final String message) {
+        this.result = result;
+        addMessage(message);
+    }
+
+    /**
+     * This Constructor creates a result with the given result status and {@link Throwable} object
+     * such as an exception. The message and stack trace from the {@link Throwable} object are added
+     * to the message list of this message.
+     *
+     * @param result the result status to use on this result
+     * @param throwable the throwable object from which to add the message and stack trace
+     */
+    public ApexAPIResult(final RESULT result, final Throwable throwable) {
+        this.result = result;
+        addThrowable(throwable);
+    }
+
+    /**
+     * This Constructor creates a result with the given result status, message, and
+     * {@link Throwable} object such as an exception. The message and stack trace from the
+     * {@link Throwable} object are added to the message list of this message.
+     *
+     * @param result the result status to use on this result
+     * @param message the message to return with the result
+     * @param throwable the throwable object from which to add the message and stack trace
+     */
+    public ApexAPIResult(final RESULT result, final String message, final Throwable throwable) {
+        this.result = result;
+        addMessage(message);
+        addThrowable(throwable);
+    }
+
+    /**
+     * This message is a utility message that checks if the result of an operation on the API was
+     * OK.
+     *
+     * @return true, if the result indicates the API operation succeeded
+     */
+    @XmlAttribute(required = true)
+    public boolean isOK() {
+        return result == RESULT.SUCCESS || result == RESULT.FINISHED;
+    }
+
+    /**
+     * This message is a utility message that checks if the result of an operation on the API was
+     * not OK.
+     *
+     * @return true, if the result indicates the API operation did not succeed
+     */
+    public boolean isNOK() {
+        return !isOK();
+    }
+
+    /**
+     * Gets the result status of an API operation.
+     *
+     * @return the result status
+     */
+    @XmlAttribute(required = true)
+    public RESULT getResult() {
+        return result;
+    }
+
+    /**
+     * Sets the result status of an API operation.
+     *
+     * @param result the result status
+     */
+    public void setResult(final RESULT result) {
+        this.result = result;
+    }
+
+    /**
+     * Gets the list of messages returned by an API operation.
+     *
+     * @return the list of messages returned by an API operation
+     */
+    @XmlElementWrapper(required = false, nillable = true)
+    @XmlElement(nillable = true, name = "message")
+    public List<String> getMessages() {
+        return messages;
+    }
+
+    /**
+     * Sets the list of messages to return as a result of an API operation.
+     *
+     * @param messages the list of messages to return as a result of an API operation
+     */
+    public void setMessages(final List<String> messages) {
+        this.messages = messages;
+    }
+
+    /**
+     * Gets all the messages returned by an API operation as a single string.
+     *
+     * @return the messages returned by an API operation as a single string
+     */
+    @XmlElement(required = true, name = "content")
+    public String getMessage() {
+        final StringBuilder builder = new StringBuilder();
+        for (final String message : messages) {
+            builder.append(message);
+            builder.append('\n');
+        }
+
+        return builder.toString();
+    }
+
+    /**
+     * Adds a message from an API operation to the bottom of the list of messages to be returned.
+     *
+     * @param message the message from an API operation to add to the bottom of the list of messages
+     *        to be returned
+     */
+    public void addMessage(final String message) {
+        if (message != null && message.trim().length() > 0) {
+            messages.add(message);
+        }
+    }
+
+    /**
+     * Adds the message and stack trace from a {@link Throwable} object such as an exception from an
+     * API operation to the bottom of the list of messages to be returned.
+     *
+     * @param throwable the {@link Throwable} object such as an exception from an API operation from
+     *        which the message and stack trace are to be extracted and placed at the bottom of the
+     *        list of messages to be returned
+     */
+    public void addThrowable(final Throwable throwable) {
+        final StringWriter throwableStringWriter = new StringWriter();
+        final PrintWriter throwablePrintWriter = new PrintWriter(throwableStringWriter);
+        throwable.printStackTrace(throwablePrintWriter);
+        messages.add(throwable.getMessage());
+        messages.add(throwableStringWriter.toString());
+    }
+
+    /**
+     * Gets a representation of the {@link ApexAPIResult} instance as a JSON string.
+     *
+     * @return the result instance JSON string
+     */
+    public String toJSON() {
+        final StringBuilder builder = new StringBuilder();
+        builder.append("{\n");
+
+        builder.append("\"result\": \"");
+        builder.append(result.toString());
+        builder.append("\",\n");
+
+        builder.append("\"messages\": [");
+        boolean first = true;
+        for (final String message : messages) {
+            if (first) {
+                builder.append("\n\"");
+                first = false;
+            } else {
+                builder.append(",\n\"");
+            }
+            builder.append(message.replaceAll("\"", "\\\\\""));
+            builder.append("\"");
+        }
+        builder.append("]\n");
+
+        builder.append("}\n");
+
+        return builder.toString();
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see java.lang.Object#toString()
+     */
+    @Override
+    public String toString() {
+        final StringBuilder builder = new StringBuilder();
+        builder.append("result: ");
+        builder.append(result);
+        builder.append('\n');
+        builder.append(getMessage());
+        return builder.toString();
+    }
+}
diff --git a/model/model-api/src/main/java/org/onap/policy/apex/model/modelapi/ApexEditorAPI.java b/model/model-api/src/main/java/org/onap/policy/apex/model/modelapi/ApexEditorAPI.java
new file mode 100644
index 000000000..617cbc786
--- /dev/null
+++ b/model/model-api/src/main/java/org/onap/policy/apex/model/modelapi/ApexEditorAPI.java
@@ -0,0 +1,948 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2016-2018 Ericsson. 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 or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * 
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.model.modelapi;
+
+/**
+ * The Interface ApexEditorAPI is used to manipulate Apex models.
+ */
+public interface ApexEditorAPI {
+    /*
+     * Model API Methods
+     */
+
+    /**
+     * Create model.
+     *
+     * @param name name of the model
+     * @param version version of the model, set to null to use the default version
+     * @param uuid model UUID, set to null to generate a UUID
+     * @param description model description, set to null to generate a description
+     * @return result of the operation
+     */
+    ApexAPIResult createModel(final String name, final String version, final String uuid, final String description);
+
+    /**
+     * Update model.
+     *
+     * @param name name of the model
+     * @param version version of the model, set to null to update the latest version
+     * @param uuid key information UUID, set to null to not update
+     * @param description policy description, set to null to not update
+     * @return result of the operation
+     */
+    ApexAPIResult updateModel(final String name, final String version, final String uuid, final String description);
+
+    /**
+     * Get the key of an Apex model.
+     *
+     * @return the result of the operation
+     */
+    ApexAPIResult getModelKey();
+
+    /**
+     * List an Apex model.
+     *
+     * @return the result of the operation
+     */
+    ApexAPIResult listModel();
+
+    /**
+     * Delete an Apex model, clear all the concepts in the model.
+     *
+     * @return the result of the operation
+     */
+    ApexAPIResult deleteModel();
+
+    /*
+     * Key Information API Methods
+     */
+
+    /**
+     * Create key information.
+     *
+     * @param name name of the concept for the key information
+     * @param version version of the concept for the key information, set to null to use the default
+     *        version
+     * @param uuid key information UUID, set to null to generate a UUID
+     * @param description key information description, set to null to generate a description
+     * @return result of the operation
+     */
+    ApexAPIResult createKeyInformation(final String name, final String version, final String uuid,
+            final String description);
+
+    /**
+     * Update key information.
+     *
+     * @param name name of the concept for the key information
+     * @param version version of the concept for the key information, set to null to update the
+     *        latest version
+     * @param uuid key information UUID, set to null to not update
+     * @param description key information description, set to null to not update
+     * @return result of the operation
+     */
+    ApexAPIResult updateKeyInformation(final String name, final String version, final String uuid,
+            final String description);
+
+    /**
+     * List key information.
+     *
+     * @param name name of the concept for the key information, set to null to list all
+     * @param version starting version of the concept for the key information, set to null to list
+     *        all versions
+     * @return result of the operation
+     */
+    ApexAPIResult listKeyInformation(final String name, final String version);
+
+    /**
+     * Delete key information.
+     *
+     * @param name name of the concept for the key information
+     * @param version version of the concept for the key information, set to null to delete all
+     *        versions
+     * @return result of the operation
+     */
+    ApexAPIResult deleteKeyInformation(final String name, final String version);
+
+    /**
+     * Validate key information.
+     *
+     * @param name name of the concept for the key information
+     * @param version version of the concept for the key information, set to null to validate all
+     *        versions
+     * @return result of the operation
+     */
+    ApexAPIResult validateKeyInformation(final String name, final String version);
+
+    /*
+     * Context Schema API Methods
+     */
+
+    /**
+     * Create a context schema.
+     *
+     * @param name name of the context schema
+     * @param version version of the context schema, set to null to use the default version
+     * @param schemaFlavour a final String identifying the flavour of this context schema
+     * @param schemaDefinition a final String containing the definition of this context schema
+     * @param uuid context schema UUID, set to null to generate a UUID
+     * @param description context schema description, set to null to generate a description
+     * @return result of the operation
+     */
+    ApexAPIResult createContextSchema(final String name, final String version, final String schemaFlavour,
+            final String schemaDefinition, final String uuid, final String description);
+
+    /**
+     * Update a context schema.
+     *
+     * @param name name of the context schema
+     * @param version version of the context schema, set to null to update the latest version
+     * @param schemaFlavour a final String identifying the flavour of this context schema
+     * @param schemaDefinition a final String containing the definition of this context schema
+     * @param uuid context schema UUID, set to null to not update
+     * @param description context schema description, set to null to not update
+     * @return result of the operation
+     */
+    ApexAPIResult updateContextSchema(final String name, final String version, final String schemaFlavour,
+            final String schemaDefinition, final String uuid, final String description);
+
+    /**
+     * List context schemas.
+     *
+     * @param name name of the context schema, set to null to list all
+     * @param version starting version of the context schema, set to null to list all versions
+     * @return result of the operation
+     */
+    ApexAPIResult listContextSchemas(final String name, final String version);
+
+    /**
+     * Delete a context schema.
+     *
+     * @param name name of the context schema
+     * @param version version of the context schema, set to null to delete all versions
+     * @return result of the operation
+     */
+    ApexAPIResult deleteContextSchema(final String name, final String version);
+
+    /**
+     * Validate context schemas.
+     *
+     * @param name name of the context schema, set to null to list all
+     * @param version starting version of the context schema, set to null to list all versions
+     * @return result of the operation
+     */
+    ApexAPIResult validateContextSchemas(final String name, final String version);
+
+    /*
+     * Event API Methods
+     */
+
+    /**
+     * Create an event.
+     *
+     * @param name name of the event
+     * @param version version of the event, set to null to use the default version
+     * @param nameSpace of the event, set to null to use the default value
+     * @param source of the event, set to null to use the default value
+     * @param target of the event, set to null to use the default value
+     * @param uuid event UUID, set to null to generate a UUID
+     * @param description event description, set to null to generate a description
+     * @return result of the operation
+     */
+    ApexAPIResult createEvent(final String name, final String version, final String nameSpace, final String source,
+            final String target, final String uuid, final String description);
+
+    /**
+     * Update an event.
+     *
+     * @param name name of the event
+     * @param version version of the event, set to null to use the latest version
+     * @param nameSpace of the event, set to null to not update
+     * @param source of the event, set to null to not update
+     * @param target of the event, set to null to not update
+     * @param uuid event UUID, set to null to not update
+     * @param description event description, set to null to not update
+     * @return result of the operation
+     */
+    ApexAPIResult updateEvent(final String name, final String version, final String nameSpace, final String source,
+            final String target, final String uuid, final String description);
+
+    /**
+     * List events.
+     *
+     * @param name name of the event, set to null to list all
+     * @param version starting version of the event, set to null to list all versions
+     * @return result of the operation
+     */
+    ApexAPIResult listEvent(final String name, final String version);
+
+    /**
+     * Delete an event.
+     *
+     * @param name name of the event
+     * @param version version of the event, set to null to delete all versions
+     * @return result of the operation
+     */
+    ApexAPIResult deleteEvent(final String name, final String version);
+
+    /**
+     * Validate events.
+     *
+     * @param name name of the event, set to null to list all
+     * @param version starting version of the event, set to null to list all versions
+     * @return result of the operation
+     */
+    ApexAPIResult validateEvent(final String name, final String version);
+
+    /**
+     * Create an event parameter.
+     *
+     * @param name name of the event
+     * @param version version of the event, set to null to use the latest version
+     * @param parName of the parameter
+     * @param contextSchemaName name of the parameter context schema
+     * @param contextSchemaVersion version of the parameter context schema, set to null to use the
+     *        latest version
+     * @param optional true if the event parameter is optional, false otherwise
+     * @return result of the operation
+     */
+    ApexAPIResult createEventPar(final String name, final String version, final String parName,
+            final String contextSchemaName, final String contextSchemaVersion, boolean optional);
+
+    /**
+     * List event parameters.
+     *
+     * @param name name of the event
+     * @param version version of the event, set to null to list latest version
+     * @param parName name of the parameter, set to null to list all parameters of the event
+     * @return result of the operation
+     */
+    ApexAPIResult listEventPar(final String name, final String version, final String parName);
+
+    /**
+     * Delete an event parameter.
+     *
+     * @param name name of the event
+     * @param version version of the event, set to null to use the latest version
+     * @param parName of the parameter, set to null to delete all parameters
+     * @return result of the operation
+     */
+    ApexAPIResult deleteEventPar(final String name, final String version, final String parName);
+
+    /*
+     * Context Album API Methods
+     */
+
+    /**
+     * Create a context album.
+     *
+     * @param name name of the context album
+     * @param version version of the context album, set to null to use the default version
+     * @param scope of the context album
+     * @param writable "true" or "t" if the context album is writable, set to null or any other
+     *        value for a read-only album
+     * @param contextSchemaName name of the parameter context schema
+     * @param contextSchemaVersion version of the parameter context schema, set to null to use the
+     *        latest version
+     * @param uuid context album UUID, set to null to generate a UUID
+     * @param description context album description, set to null to generate a description
+     * @return result of the operation
+     */
+    // CHECKSTYLE:OFF: checkstyle:parameterNumber
+    ApexAPIResult createContextAlbum(final String name, final String version, final String scope, final String writable,
+            final String contextSchemaName, final String contextSchemaVersion, final String uuid,
+            final String description);
+    // CHECKSTYLE:ON: checkstyle:parameterNumber
+
+    /**
+     * Update a context album.
+     *
+     * @param name name of the context album
+     * @param version version of the context album, set to null to use the default version
+     * @param scope of the context album
+     * @param writable "true" or "t" if the context album is writable, set to null or any other
+     *        value for a read-only album
+     * @param contextSchemaName name of the parameter context schema
+     * @param contextSchemaVersion version of the parameter context schema, set to null to use the
+     *        latest version
+     * @param uuid context album UUID, set to null to generate a UUID
+     * @param description context album description, set to null to generate a description
+     * @return result of the operation
+     */
+    // CHECKSTYLE:OFF: checkstyle:parameterNumber
+    ApexAPIResult updateContextAlbum(final String name, final String version, final String scope, final String writable,
+            final String contextSchemaName, final String contextSchemaVersion, final String uuid,
+            final String description);
+    // CHECKSTYLE:ON: checkstyle:parameterNumber
+
+    /**
+     * List context albums.
+     *
+     * @param name name of the context album, set to null to list all
+     * @param version starting version of the context album, set to null to list all versions
+     * @return result of the operation
+     */
+    ApexAPIResult listContextAlbum(final String name, final String version);
+
+    /**
+     * Delete a context album.
+     *
+     * @param name name of the context album
+     * @param version version of the context album, set to null to delete versions
+     * @return result of the operation
+     */
+    ApexAPIResult deleteContextAlbum(final String name, final String version);
+
+    /**
+     * Validate context albums.
+     *
+     * @param name name of the context album, set to null to list all
+     * @param version starting version of the context album, set to null to list all versions
+     * @return result of the operation
+     */
+    ApexAPIResult validateContextAlbum(final String name, final String version);
+
+    /*
+     * Task API Methods
+     */
+
+    /**
+     * Create a task.
+     *
+     * @param name name of the task
+     * @param version version of the task, set to null to use the default version
+     * @param uuid task UUID, set to null to generate a UUID
+     * @param description task description, set to null to generate a description
+     * @return result of the operation
+     */
+    ApexAPIResult createTask(final String name, final String version, final String uuid, final String description);
+
+    /**
+     * Update a task.
+     *
+     * @param name name of the task
+     * @param version version of the task, set to null to use the latest version
+     * @param uuid task UUID, set to null to not update
+     * @param description task description, set to null to not update
+     * @return result of the operation
+     */
+    ApexAPIResult updateTask(final String name, final String version, final String uuid, final String description);
+
+    /**
+     * List tasks.
+     *
+     * @param name name of the task, set to null to list all
+     * @param version starting version of the task, set to null to list all versions
+     * @return result of the operation
+     */
+    ApexAPIResult listTask(final String name, final String version);
+
+    /**
+     * Delete a task.
+     *
+     * @param name name of the task
+     * @param version version of the task, set to null to use the latest version
+     * @return result of the operation
+     */
+    ApexAPIResult deleteTask(final String name, final String version);
+
+    /**
+     * Validate tasks.
+     *
+     * @param name name of the task, set to null to list all
+     * @param version starting version of the task, set to null to list all versions
+     * @return result of the operation
+     */
+    ApexAPIResult validateTask(final String name, final String version);
+
+    /**
+     * Create logic for a task.
+     *
+     * @param name name of the task
+     * @param version version of the task, set to null to use the latest version
+     * @param logicFlavour the task logic flavour for the task, set to null to use the default task
+     *        logic flavour
+     * @param logic the source code for the logic of the task
+     * @return result of the operation
+     */
+    ApexAPIResult createTaskLogic(final String name, final String version, final String logicFlavour,
+            final String logic);
+
+    /**
+     * Update logic for a task.
+     *
+     * @param name name of the task
+     * @param version version of the task, set to null to use the latest version
+     * @param logicFlavour the task logic flavour for the task, set to null to not update
+     * @param logic the source code for the logic of the task, set to null to not update
+     * @return result of the operation
+     */
+    ApexAPIResult updateTaskLogic(final String name, final String version, final String logicFlavour,
+            final String logic);
+
+    /**
+     * List task logic.
+     *
+     * @param name name of the task
+     * @param version version of the task, set to null to list the latest version
+     * @return result of the operation
+     */
+    ApexAPIResult listTaskLogic(final String name, final String version);
+
+    /**
+     * Delete logic for a task.
+     *
+     * @param name name of the task
+     * @param version version of the task, set to null to use the latest version
+     * @return result of the operation
+     */
+    ApexAPIResult deleteTaskLogic(final String name, final String version);
+
+    /**
+     * Create a task input field.
+     *
+     * @param name name of the task
+     * @param version version of the task, set to null to use the latest version
+     * @param fieldName of the input field
+     * @param contextSchemaName name of the input field context schema
+     * @param contextSchemaVersion version of the input field context schema, set to null to use the
+     *        latest version
+     * @param optional true if the task field is optional, false otherwise
+     * @return result of the operation
+     */
+    ApexAPIResult createTaskInputField(final String name, final String version, final String fieldName,
+            final String contextSchemaName, final String contextSchemaVersion, boolean optional);
+
+    /**
+     * List task input fields.
+     *
+     * @param name name of the task
+     * @param version version of the task, set to null to use the latest version
+     * @param fieldName field name of the input field, set to null to list all input fields of the
+     *        task
+     * @return result of the operation
+     */
+    ApexAPIResult listTaskInputField(final String name, final String version, final String fieldName);
+
+    /**
+     * Delete a task input field.
+     *
+     * @param name name of the task
+     * @param version version of the task, set to null to use the latest version
+     * @param fieldName of the input field, set to null to delete all input fields
+     * @return result of the operation
+     */
+    ApexAPIResult deleteTaskInputField(final String name, final String version, final String fieldName);
+
+    /**
+     * Create a task output field.
+     *
+     * @param name name of the task
+     * @param version version of the task, set to null to use the latest version
+     * @param fieldName of the output field
+     * @param contextSchemaName name of the output field context schema
+     * @param contextSchemaVersion version of the output field context schema, set to null to use
+     *        the latest version
+     * @param optional true if the task field is optional, false otherwise
+     * @return result of the operation
+     */
+    ApexAPIResult createTaskOutputField(final String name, final String version, final String fieldName,
+            final String contextSchemaName, final String contextSchemaVersion, boolean optional);
+
+    /**
+     * List task output fields.
+     *
+     * @param name name of the task
+     * @param version version of the task, set to null to use the latest version
+     * @param fieldName field name of the output field, set to null to list all output fields of the
+     *        task
+     * @return result of the operation
+     */
+    ApexAPIResult listTaskOutputField(final String name, final String version, final String fieldName);
+
+    /**
+     * Delete a task output field.
+     *
+     * @param name name of the task
+     * @param version version of the task, set to null to use the latest version
+     * @param fieldName of the output field, set to null to delete all output fields
+     * @return result of the operation
+     */
+    ApexAPIResult deleteTaskOutputField(final String name, final String version, final String fieldName);
+
+    /**
+     * Create a task parameter.
+     *
+     * @param name name of the task
+     * @param version version of the task, set to null to use the latest version
+     * @param parName of the parameter
+     * @param defaultValue of the parameter
+     * @return result of the operation
+     */
+    ApexAPIResult createTaskParameter(final String name, final String version, final String parName,
+            final String defaultValue);
+
+    /**
+     * List task parameters.
+     *
+     * @param name name of the task
+     * @param version version of the task, set to null to use the latest version
+     * @param parName name of the parameter, set to null to list all parameters of the task
+     * @return result of the operation
+     */
+    ApexAPIResult listTaskParameter(final String name, final String version, final String parName);
+
+    /**
+     * Delete a task parameter.
+     *
+     * @param name name of the task
+     * @param version version of the task, set to null to use the latest version
+     * @param parName of the parameter, set to null to delete all task parameters
+     * @return result of the operation
+     */
+    ApexAPIResult deleteTaskParameter(final String name, final String version, final String parName);
+
+    /**
+     * Create a task context album reference.
+     *
+     * @param name name of the task
+     * @param version version of the task, set to null to use the latest version
+     * @param contextAlbumName name of the context album for the context album reference
+     * @param contextAlbumVersion version of the context album for the context album reference, set
+     *        to null to use the latest version
+     * @return result of the operation
+     */
+    ApexAPIResult createTaskContextRef(final String name, final String version, final String contextAlbumName,
+            final String contextAlbumVersion);
+
+    /**
+     * List task context album references.
+     *
+     * @param name name of the task
+     * @param version version of the task, set to null to use the latest version
+     * @param contextAlbumName name of the context album for the context album reference, set to
+     *        null to list all task context album references
+     * @param contextAlbumVersion version of the context album for the context album reference, set
+     *        to null to use the latest version
+     * @return result of the operation
+     */
+    ApexAPIResult listTaskContextRef(final String name, final String version, final String contextAlbumName,
+            final String contextAlbumVersion);
+
+    /**
+     * Delete a task context album reference.
+     *
+     * @param name name of the task
+     * @param version version of the task, set to null to use the latest version
+     * @param contextAlbumName name of the context album for the context album reference, set to
+     *        null to delete all task context album references
+     * @param contextAlbumVersion version of the context album for the context album reference, set
+     *        to null to use the latest version
+     * @return result of the operation
+     */
+    ApexAPIResult deleteTaskContextRef(final String name, final String version, final String contextAlbumName,
+            final String contextAlbumVersion);
+
+    /*
+     * Policy API Methods
+     */
+
+    /**
+     * Create a policy.
+     *
+     * @param name name of the policy
+     * @param version version of the policy, set to null to use the default version
+     * @param template template used to create the policy, set to null to use the default template
+     * @param firstState the first state of the policy
+     * @param uuid policy UUID, set to null to generate a UUID
+     * @param description policy description, set to null to generate a description
+     * @return result of the operation
+     */
+    ApexAPIResult createPolicy(final String name, final String version, final String template, final String firstState,
+            final String uuid, final String description);
+
+    /**
+     * Update a policy.
+     *
+     * @param name name of the policy
+     * @param version version of the policy, set to null to use the latest version
+     * @param template template used to create the policy, set to null to not update
+     * @param firstState the first state of the policy
+     * @param uuid policy UUID, set to null to not update
+     * @param description policy description, set to null to not update
+     * @return result of the operation
+     */
+    ApexAPIResult updatePolicy(final String name, final String version, final String template, final String firstState,
+            final String uuid, final String description);
+
+    /**
+     * List policies.
+     *
+     * @param name name of the policy, set to null to list all
+     * @param version starting version of the policy, set to null to list all versions
+     * @return result of the operation
+     */
+    ApexAPIResult listPolicy(final String name, final String version);
+
+    /**
+     * Delete a policy.
+     *
+     * @param name name of the policy
+     * @param version version of the policy, set to null to use the latest version
+     * @return result of the operation
+     */
+    ApexAPIResult deletePolicy(final String name, final String version);
+
+    /**
+     * Validate policies.
+     *
+     * @param name name of the policy, set to null to list all
+     * @param version starting version of the policy, set to null to list all versions
+     * @return result of the operation
+     */
+    ApexAPIResult validatePolicy(final String name, final String version);
+
+    /**
+     * Create a policy state.
+     *
+     * @param name name of the policy
+     * @param version version of the policy, set to null to use the latest version
+     * @param stateName of the state
+     * @param triggerName name of the trigger event for this state
+     * @param triggerVersion version of the trigger event for this state, set to null to use the
+     *        latest version
+     * @param defaultTaskName the default task name
+     * @param defaltTaskVersion the default task version, set to null to use the latest version
+     * @return result of the operation
+     */
+    ApexAPIResult createPolicyState(final String name, final String version, final String stateName,
+            final String triggerName, final String triggerVersion, final String defaultTaskName,
+            final String defaltTaskVersion);
+
+    /**
+     * Update a policy state.
+     *
+     * @param name name of the policy
+     * @param version version of the policy, set to null to use the latest version
+     * @param stateName of the state
+     * @param triggerName name of the trigger event for this state, set to null to not update
+     * @param triggerVersion version of the trigger event for this state, set to use latest version
+     *        of trigger event
+     * @param defaultTaskName the default task name, set to null to not update
+     * @param defaltTaskVersion the default task version, set to use latest version of default task
+     * @return result of the operation
+     */
+    ApexAPIResult updatePolicyState(final String name, final String version, final String stateName,
+            final String triggerName, final String triggerVersion, final String defaultTaskName,
+            final String defaltTaskVersion);
+
+    /**
+     * List policy states.
+     *
+     * @param name name of the policy
+     * @param version version of the policy, set to null to use the latest version
+     * @param stateName of the state, set to null to list all states of the policy
+     * @return result of the operation
+     */
+    ApexAPIResult listPolicyState(final String name, final String version, final String stateName);
+
+    /**
+     * Delete a policy state.
+     *
+     * @param name name of the policy
+     * @param version version of the policy, set to null to use the latest version
+     * @param stateName of the state, set to null to delete all states
+     * @return result of the operation
+     */
+    ApexAPIResult deletePolicyState(final String name, final String version, final String stateName);
+
+    /**
+     * Create task selection logic for a state.
+     *
+     * @param name name of the policy
+     * @param version version of the policy, set to null to use the latest version
+     * @param stateName of the state
+     * @param logicFlavour the task selection logic flavour for the state, set to null to use the
+     *        default task logic flavour
+     * @param logic the source code for the logic of the state
+     * @return result of the operation
+     */
+    ApexAPIResult createPolicyStateTaskSelectionLogic(final String name, final String version, final String stateName,
+            final String logicFlavour, final String logic);
+
+    /**
+     * Update task selection logic for a state.
+     *
+     * @param name name of the policy
+     * @param version version of the policy, set to null to use the latest version
+     * @param stateName of the state
+     * @param logicFlavour the task selection logic flavour for the state, set to null to not update
+     * @param logic the source code for the logic of the state, set to null to not update
+     * @return result of the operation
+     */
+    ApexAPIResult updatePolicyStateTaskSelectionLogic(final String name, final String version, final String stateName,
+            final String logicFlavour, final String logic);
+
+    /**
+     * List task selection logic for a state.
+     *
+     * @param name name of the policy
+     * @param version version of the policy, set to null to use the latest version
+     * @param stateName of the state
+     * @return result of the operation
+     */
+    ApexAPIResult listPolicyStateTaskSelectionLogic(final String name, final String version, final String stateName);
+
+    /**
+     * Delete task selection logic for a state.
+     *
+     * @param name name of the policy
+     * @param version version of the policy, set to null to use the latest version
+     * @param stateName of the state
+     * @return result of the operation
+     */
+    ApexAPIResult deletePolicyStateTaskSelectionLogic(final String name, final String version, final String stateName);
+
+    /**
+     * Create a policy state output.
+     *
+     * @param name name of the policy
+     * @param version version of the policy, set to null to use the latest version
+     * @param stateName of the state
+     * @param outputName of the state output
+     * @param eventName name of the output event for this state output
+     * @param eventVersion version of the output event for this state output, set to null to use the
+     *        latest version
+     * @param nextState for this state to transition to, set to null if this is the last state that
+     *        the policy transitions to on this branch
+     * @return result of the operation
+     */
+    ApexAPIResult createPolicyStateOutput(final String name, final String version, final String stateName,
+            final String outputName, final String eventName, final String eventVersion, final String nextState);
+
+    /**
+     * List policy state outputs.
+     *
+     * @param name name of the policy
+     * @param version version of the policy, set to null to use the latest version
+     * @param stateName of the state
+     * @param outputName of the state output, set to null to list all outputs of the state
+     * @return result of the operation
+     */
+    ApexAPIResult listPolicyStateOutput(final String name, final String version, final String stateName,
+            final String outputName);
+
+    /**
+     * Delete a policy state output.
+     *
+     * @param name name of the policy
+     * @param version version of the policy, set to null to use the latest version
+     * @param stateName of the state
+     * @param outputName of the state output, set to null to delete all state outputs
+     * @return result of the operation
+     */
+    ApexAPIResult deletePolicyStateOutput(final String name, final String version, final String stateName,
+            final String outputName);
+
+    /**
+     * Create policy finalizer logic for a state.
+     *
+     * @param name name of the policy
+     * @param version version of the policy, set to null to use the latest version
+     * @param stateName of the state
+     * @param finalizerLogicName name of the state finalizer logic
+     * @param logicFlavour the policy finalizer logic flavour for the state, set to null to use the
+     *        default task logic flavour
+     * @param logic the source code for the logic of the state
+     * @return result of the operation
+     */
+    ApexAPIResult createPolicyStateFinalizerLogic(final String name, final String version, final String stateName,
+            final String finalizerLogicName, final String logicFlavour, final String logic);
+
+    /**
+     * Update policy finalizer logic for a state.
+     *
+     * @param name name of the policy
+     * @param version version of the policy, set to null to use the latest version
+     * @param stateName of the state
+     * @param finalizerLogicName name of the state finalizer logic
+     * @param logicFlavour the policy finalizer logic flavour for the state, set to null to not
+     *        update
+     * @param logic the source code for the logic of the state, set to null to not update
+     * @return result of the operation
+     */
+    ApexAPIResult updatePolicyStateFinalizerLogic(final String name, final String version, final String stateName,
+            final String finalizerLogicName, final String logicFlavour, final String logic);
+
+    /**
+     * List policy finalizer logic for a state.
+     *
+     * @param name name of the policy
+     * @param version version of the policy, set to null to use the latest version
+     * @param stateName of the state
+     * @param finalizerLogicName name of the state finalizer logic
+     * @return result of the operation
+     */
+    ApexAPIResult listPolicyStateFinalizerLogic(final String name, final String version, final String stateName,
+            final String finalizerLogicName);
+
+    /**
+     * Delete policy finalizer logic for a state.
+     *
+     * @param name name of the policy
+     * @param version version of the policy, set to null to use the latest version
+     * @param stateName of the state
+     * @param finalizerLogicName name of the state finalizer logic
+     * @return result of the operation
+     */
+    ApexAPIResult deletePolicyStateFinalizerLogic(final String name, final String version, final String stateName,
+            final String finalizerLogicName);
+
+    /**
+     * Create a policy state task reference.
+     *
+     * @param name name of the policy
+     * @param version version of the policy, set to null to use the latest version
+     * @param stateName of the state
+     * @param taskLocalName the task local name
+     * @param taskName name of the task
+     * @param taskVersion version of the task, set to null to use the latest version
+     * @param outputType Type of output for the task, must be DIRECT for direct output to a state
+     *        output or LOGIC for output to state finalizer logic
+     * @param outputName the name of the state output or state state finalizer logic to handle the
+     *        task output
+     * @return result of the operation
+     */
+    // CHECKSTYLE:OFF: checkstyle:parameterNumber
+    ApexAPIResult createPolicyStateTaskRef(final String name, final String version, final String stateName,
+            final String taskLocalName, final String taskName, final String taskVersion, final String outputType,
+            final String outputName);
+    // CHECKSTYLE:ON: checkstyle:parameterNumber
+
+    /**
+     * List policy state task references.
+     *
+     * @param name name of the policy
+     * @param version version of the policy, set to null to use the latest version
+     * @param stateName of the state
+     * @param taskName name of the task, set to null to list all task references
+     * @param taskVersion version of the task, set to null to use the latest version
+     * @return result of the operation
+     */
+    ApexAPIResult listPolicyStateTaskRef(final String name, final String version, final String stateName,
+            final String taskName, final String taskVersion);
+
+    /**
+     * Delete a policy state task reference.
+     *
+     * @param name name of the policy
+     * @param version version of the policy, set to null to use the latest version
+     * @param stateName of the state
+     * @param taskName name of the task, set to null to delete all task references
+     * @param taskVersion version of the task, set to null to use the latest version
+     * @return result of the operation
+     */
+    ApexAPIResult deletePolicyStateTaskRef(final String name, final String version, final String stateName,
+            final String taskName, final String taskVersion);
+
+    /**
+     * Create a policy state context album reference.
+     *
+     * @param name name of the policy
+     * @param version version of the policy, set to null to use the latest version
+     * @param stateName of the state
+     * @param contextAlbumName name of the context album for the context album reference
+     * @param contextAlbumVersion version of the context album for the context album reference, set
+     *        to null to use the latest version
+     * @return result of the operation
+     */
+    ApexAPIResult createPolicyStateContextRef(final String name, final String version, final String stateName,
+            final String contextAlbumName, final String contextAlbumVersion);
+
+    /**
+     * List policy state context album references.
+     *
+     * @param name name of the policy
+     * @param version version of the policy, set to null to use the latest version
+     * @param stateName of the state
+     * @param contextAlbumName name of the context album for the context album reference, set to
+     *        null to list all task context album references
+     * @param contextAlbumVersion version of the context album for the context album reference, set
+     *        to null to use the latest version
+     * @return result of the operation
+     */
+    ApexAPIResult listPolicyStateContextRef(final String name, final String version, final String stateName,
+            final String contextAlbumName, final String contextAlbumVersion);
+
+    /**
+     * Delete a policy state context album reference.
+     *
+     * @param name name of the policy
+     * @param version version of the policy, set to null to use the default version
+     * @param stateName of the state
+     * @param contextAlbumName name of the context album for the context album reference, set to
+     *        null to delete all task context album references
+     * @param contextAlbumVersion version of the context album for the context album reference, set
+     *        to null to use the latest version
+     * @return result of the operation
+     */
+    ApexAPIResult deletePolicyStateContextRef(final String name, final String version, final String stateName,
+            final String contextAlbumName, final String contextAlbumVersion);
+}
diff --git a/model/model-api/src/main/java/org/onap/policy/apex/model/modelapi/ApexModel.java b/model/model-api/src/main/java/org/onap/policy/apex/model/modelapi/ApexModel.java
new file mode 100644
index 000000000..c9190b8db
--- /dev/null
+++ b/model/model-api/src/main/java/org/onap/policy/apex/model/modelapi/ApexModel.java
@@ -0,0 +1,192 @@
+/*
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2016-2018 Ericsson. 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 or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * 
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.model.modelapi;
+
+import org.onap.policy.apex.model.basicmodel.dao.DAOParameters;
+import org.onap.policy.apex.model.policymodel.concepts.AxPolicyModel;
+
+/**
+ * The Interface ApexModelAPI provides functional methods that allow Apex models to be managed.
+ *
+ * @author Liam Fallon (liam.fallon@ericsson.com)
+ */
+public interface ApexModel extends ApexEditorAPI {
+    /**
+     * Make a deep copy of the Model.
+     *
+     * @return the result of the operation
+     */
+    ApexModel clone();
+
+    /**
+     * Load an Apex model from a string.
+     *
+     * @param modelString the string with the model
+     * @return the result of the operation
+     */
+    ApexAPIResult loadFromString(String modelString);
+
+    /**
+     * Load an Apex model from a file.
+     *
+     * @param fileName the file name of the file with the model
+     * @return the result of the operation
+     */
+    ApexAPIResult loadFromFile(String fileName);
+
+    /**
+     * Save an Apex model to a file.
+     *
+     * @param fileName the file name
+     * @param xmlFlag if true, save the file in XML format, otherwise save the file in the default JSON format
+     * @return the result of the operation
+     */
+    ApexAPIResult saveToFile(String fileName, boolean xmlFlag);
+
+    /**
+     * Load an Apex model from a database.
+     *
+     * @param modelName the name of the model to load
+     * @param modelVersion the version of the model to load, loads the policy model from the database with this name, if more than one exist, an exception is
+     *            thrown
+     * @param daoParameters the parameters to use to access the database over JDBC
+     * @return the result of the operation
+     */
+    ApexAPIResult loadFromDatabase(String modelName, String modelVersion, DAOParameters daoParameters);
+
+    /**
+     * Save an Apex model to a database.
+     *
+     * @param daoParameters the parameters to use to access the database over JDBC
+     * @return the result of the operation
+     */
+    ApexAPIResult saveToDatabase(DAOParameters daoParameters);
+
+    /**
+     * Read an APEX model from a location identified by a URL.
+     *
+     * @param urlString the url string
+     * @return the result of the operation
+     */
+    ApexAPIResult readFromURL(String urlString);
+
+    /**
+     * Write an APEX model to a location identified by a URL.
+     *
+     * @param urlString the URL to read the model from
+     * @param xmlFlag if true, save the file in XML format, otherwise save the file in the default JSON format
+     * @return the result of the operation
+     */
+    ApexAPIResult writeToURL(String urlString, boolean xmlFlag);
+
+    /**
+     * Analyse an Apex model that shows the concept usage references of a policy model.
+     *
+     * @return the result of the operation
+     */
+    ApexAPIResult analyse();
+
+    /**
+     * Validate an Apex model, checking all concepts and references in the model.
+     *
+     * @return the result of the operation
+     */
+    ApexAPIResult validate();
+
+    /**
+     * Compare to Apex models, returning the differences between the models.
+     *
+     * @param otherModelFileName the file name of the other model
+     * @param diffsOnly only returns differences between the model when set
+     * @param keysOnly only returns the keys that are different when set, when not set values are also returned
+     * @return the result of the operation
+     */
+    ApexAPIResult compare(String otherModelFileName, boolean diffsOnly, boolean keysOnly);
+
+    /**
+     * Compare two Apex models, returning the differences between the models.
+     *
+     * @param otherModelString the other model as a string
+     * @param diffsOnly only returns differences between the model when set
+     * @param keysOnly only returns the keys that are different when set, when not set values are also returned
+     * @return the result of the operation
+     */
+    ApexAPIResult compareWithString(String otherModelString, boolean diffsOnly, boolean keysOnly);
+
+    /**
+     * Split out a sub model from an Apex model that contains a given subset of the policies in the original model.
+     *
+     * @param targetModelName the file name of the target model in which to store the model split out from the original model
+     * @param splitOutPolicies the policies form the original model to include in the split out model, specified as a comma delimited list of policy names
+     * @return the result of the operation
+     */
+    ApexAPIResult split(String targetModelName, String splitOutPolicies);
+
+    /**
+     * Split out a sub model from an Apex model that contains a given subset of the policies in the original model, return the split model in the result as a
+     * string.
+     *
+     * @param splitOutPolicies the policies form the original model to include in the split out model, specified as a comma delimited list of policy names
+     * @return the result of the operation
+     */
+    ApexAPIResult split(String splitOutPolicies);
+
+    /**
+     * Merge two Apex models together.
+     *
+     * @param mergeInModelName the file name of the model to merge into the current model
+     * @param keepOriginal if this flag is set to true, if a concept exists in both models, the original model copy of that concept is kept, if the flag is set
+     *            to false, then the copy of the concept from the mergeInModel overwrites the concept in the original model
+     * @return the result of the operation
+     */
+    ApexAPIResult merge(String mergeInModelName, boolean keepOriginal);
+
+    /**
+     * Merge two Apex models together.
+     *
+     * @param otherModelString the model to merge as a string
+     * @param keepOriginal if this flag is set to true, if a concept exists in both models, the original model copy of that concept is kept, if the flag is set
+     *            to false, then the copy of the concept from the mergeInModel overwrites the concept in the original model
+     * @return the result of the operation
+     */
+    ApexAPIResult mergeWithString(String otherModelString, boolean keepOriginal);
+
+    /**
+     * Get the raw policy model being used by this model.
+     *
+     * @return the policy model
+     */
+    AxPolicyModel getPolicyModel();
+
+    /**
+     * Set the raw policy model being used by this model.
+     *
+     * @param policyModel the policy model
+     */
+    void setPolicyModel(AxPolicyModel policyModel);
+    
+    /**
+     * Builds the raw policy model being used by this model.
+     *
+     * @return the policy model
+     */
+    AxPolicyModel build();
+}
diff --git a/model/model-api/src/main/java/org/onap/policy/apex/model/modelapi/ApexModelFactory.java b/model/model-api/src/main/java/org/onap/policy/apex/model/modelapi/ApexModelFactory.java
new file mode 100644
index 000000000..ad0f0b4fa
--- /dev/null
+++ b/model/model-api/src/main/java/org/onap/policy/apex/model/modelapi/ApexModelFactory.java
@@ -0,0 +1,78 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2016-2018 Ericsson. 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 or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * 
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.model.modelapi;
+
+import java.util.Properties;
+
+import org.onap.policy.apex.model.modelapi.impl.ApexModelImpl;
+
+/**
+ * A factory for creating ApexModel objects using the Apex Model implementation.
+ *
+ * @author Liam Fallon (liam.fallon@ericsson.com)
+ */
+public class ApexModelFactory {
+
+    /**
+     * Creates a new ApexModel object from its implementation.
+     *
+     * @param apexProperties default values and other configuration information for the apex model
+     * @param jsonMode set to true to return JSON strings in list and delete operations, otherwise
+     *        set to false
+     * @return the apex model
+     */
+    public ApexModel createApexModel(final Properties apexProperties, final boolean jsonMode) {
+        return new ApexModelImpl(setDefaultPropertyValues(apexProperties), jsonMode);
+    }
+
+    /**
+     * Sets default property values for Apex properties that must be set for the Apex model
+     * implementation if those properties are not already set.
+     *
+     * @param apexPropertiesIn the default property values
+     * @return the properties
+     */
+    private Properties setDefaultPropertyValues(final Properties apexPropertiesIn) {
+        Properties apexProperties = apexPropertiesIn;
+
+        if (apexProperties == null) {
+            apexProperties = new Properties();
+        }
+
+        if (apexProperties.getProperty("DEFAULT_CONCEPT_VERSION") == null) {
+            apexProperties.setProperty("DEFAULT_CONCEPT_VERSION", "0.0.1");
+        }
+        if (apexProperties.getProperty("DEFAULT_EVENT_NAMESPACE") == null) {
+            apexProperties.setProperty("DEFAULT_EVENT_NAMESPACE", "org.onap.policy.apex");
+        }
+        if (apexProperties.getProperty("DEFAULT_EVENT_SOURCE") == null) {
+            apexProperties.setProperty("DEFAULT_EVENT_SOURCE", "source");
+        }
+        if (apexProperties.getProperty("DEFAULT_EVENT_TARGET") == null) {
+            apexProperties.setProperty("DEFAULT_EVENT_TARGET", "target");
+        }
+        if (apexProperties.getProperty("DEFAULT_POLICY_TEMPLATE") == null) {
+            apexProperties.setProperty("DEFAULT_POLICY_TEMPLATE", "FREEFORM");
+        }
+
+        return apexProperties;
+    }
+}
diff --git a/model/model-api/src/main/java/org/onap/policy/apex/model/modelapi/impl/ApexModelImpl.java b/model/model-api/src/main/java/org/onap/policy/apex/model/modelapi/impl/ApexModelImpl.java
new file mode 100644
index 000000000..5303e9502
--- /dev/null
+++ b/model/model-api/src/main/java/org/onap/policy/apex/model/modelapi/impl/ApexModelImpl.java
@@ -0,0 +1,1239 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2016-2018 Ericsson. 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 or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * 
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.model.modelapi.impl;
+
+import java.util.Properties;
+
+import org.onap.policy.apex.model.basicmodel.dao.DAOParameters;
+import org.onap.policy.apex.model.modelapi.ApexAPIResult;
+import org.onap.policy.apex.model.modelapi.ApexModel;
+import org.onap.policy.apex.model.policymodel.concepts.AxPolicyModel;
+
+/**
+ * This class is an implementation of a facade on an Apex model for editors of Apex models.
+ *
+ * @author Liam Fallon (liam.fallon@ericsson.com)
+ */
+public final class ApexModelImpl implements ApexModel {
+    private static final int HASH_CODE_PRIME_0 = 31;
+    private static final int HASH_CODE_PRIME_1 = 1231;
+    private static final int HASH_CODE_PRIME_2 = 1237;
+
+    // The policy model being acted upon
+    private AxPolicyModel policyModel = new AxPolicyModel();
+
+    // The file name for the loaded file
+    private String fileName = null;
+
+    // Facade classes for working towards the real Apex model
+    // @formatter:off
+    private ModelFacade modelFacade;
+    private KeyInformationFacade keyInformationFacade;
+    private ContextSchemaFacade contextSchemaFacade;
+    private EventFacade eventFacade;
+    private ContextAlbumFacade contextAlbumFacade;
+    private TaskFacade taskFacade;
+    private PolicyFacade policyFacade;
+    private ModelHandlerFacade modelHandlerFacade;
+    // @formatter:on
+
+    private Properties apexProperties;
+    private boolean jsonMode;
+
+    /**
+     * Create an implementation of the Apex editor and model APIs.
+     *
+     * @param apexProperties The properties to use for the model
+     * @param jsonMode set to true to return JSON strings in list and delete operations, otherwise
+     *        set to false
+     */
+    public ApexModelImpl(final Properties apexProperties, final boolean jsonMode) {
+        this.apexProperties = apexProperties;
+        this.jsonMode = jsonMode;
+
+        // @formatter:off
+        this.modelFacade          = new ModelFacade(this, apexProperties, jsonMode);
+        this.keyInformationFacade = new KeyInformationFacade(this, apexProperties, jsonMode);
+        this.contextSchemaFacade  = new ContextSchemaFacade(this, apexProperties, jsonMode);
+        this.eventFacade          = new EventFacade(this, apexProperties, jsonMode);
+        this.contextAlbumFacade   = new ContextAlbumFacade(this, apexProperties, jsonMode);
+        this.taskFacade           = new TaskFacade(this, apexProperties, jsonMode);
+        this.policyFacade         = new PolicyFacade(this, apexProperties, jsonMode);
+        this.modelHandlerFacade   = new ModelHandlerFacade(this, apexProperties, jsonMode);
+        // @formatter:on
+    }
+
+    /**
+     * Constructor, prevents this class being sub-classed.
+     */
+    private ApexModelImpl() {}
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see org.onap.policy.apex.core.modelapi.ApexModel#clone()
+     */
+    @Override
+    public ApexModel clone() {
+        ApexModelImpl ret = new ApexModelImpl();
+        // @formatter:off
+        ret.policyModel          = new AxPolicyModel(policyModel);
+        ret.fileName             = this.fileName;
+        ret.apexProperties       = this.apexProperties;
+        ret.jsonMode             = this.jsonMode;
+        ret.modelFacade          = new ModelFacade(ret, this.apexProperties, this.jsonMode);
+        ret.keyInformationFacade = new KeyInformationFacade(ret, this.apexProperties, this.jsonMode);
+        ret.contextSchemaFacade  = new ContextSchemaFacade(ret, this.apexProperties, this.jsonMode);
+        ret.eventFacade          = new EventFacade(ret, this.apexProperties, this.jsonMode);
+        ret.contextAlbumFacade   = new ContextAlbumFacade(ret, this.apexProperties, this.jsonMode);
+        ret.taskFacade           = new TaskFacade(ret, this.apexProperties, this.jsonMode);
+        ret.policyFacade         = new PolicyFacade(ret, this.apexProperties, this.jsonMode);
+        ret.modelHandlerFacade   = new ModelHandlerFacade(ret, this.apexProperties, this.jsonMode);
+        // @formatter:on
+
+        return ret;
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see org.onap.policy.apex.core.modelapi.ApexModel#createModel(java.lang.String,
+     * java.lang.String, java.lang.String, java.lang.String)
+     */
+    @Override
+    public ApexAPIResult createModel(final String name, final String version, final String uuid,
+            final String description) {
+        return modelFacade.createModel(name, version, uuid, description);
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see org.onap.policy.apex.core.modelapi.ApexModel#updateModel(java.lang.String,
+     * java.lang.String, java.lang.String, java.lang.String)
+     */
+    @Override
+    public ApexAPIResult updateModel(final String name, final String version, final String uuid,
+            final String description) {
+        return modelFacade.updateModel(name, version, uuid, description);
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see org.onap.policy.apex.core.modelapi.ApexEditorAPI#getModelKey()
+     */
+    @Override
+    public ApexAPIResult getModelKey() {
+        return modelFacade.getModelKey();
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see org.onap.policy.apex.auth.api.ApexEditorAPI#listModel()
+     */
+    @Override
+    public ApexAPIResult listModel() {
+        return modelFacade.listModel();
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see org.onap.policy.apex.auth.api.ApexEditorAPI#deleteModel()
+     */
+    @Override
+    public ApexAPIResult deleteModel() {
+        return modelFacade.deleteModel();
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see org.onap.policy.apex.auth.api.ApexEditorAPI#createKeyInformation(java.lang.String,
+     * java.lang.String, java.lang.String, java.lang.String)
+     */
+    @Override
+    public ApexAPIResult createKeyInformation(final String name, final String version, final String uuid,
+            final String description) {
+        return keyInformationFacade.createKeyInformation(name, version, uuid, description);
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see org.onap.policy.apex.auth.api.ApexEditorAPI#updateKeyInformation(java.lang.String,
+     * java.lang.String, java.lang.String, java.lang.String)
+     */
+    @Override
+    public ApexAPIResult updateKeyInformation(final String name, final String version, final String uuid,
+            final String description) {
+        return keyInformationFacade.updateKeyInformation(name, version, uuid, description);
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see org.onap.policy.apex.auth.api.ApexEditorAPI#listKeyInformation(java.lang.String,
+     * java.lang.String)
+     */
+    @Override
+    public ApexAPIResult listKeyInformation(final String name, final String version) {
+        return keyInformationFacade.listKeyInformation(name, version);
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see org.onap.policy.apex.auth.api.ApexEditorAPI#deleteKeyInformation(java.lang.String,
+     * java.lang.String)
+     */
+    @Override
+    public ApexAPIResult deleteKeyInformation(final String name, final String version) {
+        return keyInformationFacade.deleteKeyInformation(name, version);
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see org.onap.policy.apex.auth.api.ApexEditorAPI#validateKeyInformation(java.lang.String,
+     * java.lang.String)
+     */
+    @Override
+    public ApexAPIResult validateKeyInformation(final String name, final String version) {
+        return keyInformationFacade.validateKeyInformation(name, version);
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see org.onap.policy.apex.auth.api.ApexEditorAPI#createContextSchema(java.lang.String,
+     * java.lang.String, java.lang.String, java.lang.String, java.lang.String, java.lang.String)
+     */
+    @Override
+    public ApexAPIResult createContextSchema(final String name, final String version, final String schemaFlavour,
+            final String schemaDefinition, final String uuid, final String description) {
+        return contextSchemaFacade.createContextSchema(name, version, schemaFlavour, schemaDefinition, uuid,
+                description);
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see org.onap.policy.apex.auth.api.ApexEditorAPI#updateContextSchema(java.lang.String,
+     * java.lang.String, java.lang.String, java.lang.String, java.lang.String, java.lang.String)
+     */
+    @Override
+    public ApexAPIResult updateContextSchema(final String name, final String version, final String schemaFlavour,
+            final String schemaDefinition, final String uuid, final String description) {
+        return contextSchemaFacade.updateContextSchema(name, version, schemaFlavour, schemaDefinition, uuid,
+                description);
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see org.onap.policy.apex.auth.api.ApexEditorAPI#listContextSchemas(java.lang.String,
+     * java.lang.String)
+     */
+    @Override
+    public ApexAPIResult listContextSchemas(final String name, final String version) {
+        return contextSchemaFacade.listContextSchemas(name, version);
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see org.onap.policy.apex.auth.api.ApexEditorAPI#deleteContextSchema(java.lang.String,
+     * java.lang.String)
+     */
+    @Override
+    public ApexAPIResult deleteContextSchema(final String name, final String version) {
+        return contextSchemaFacade.deleteContextSchema(name, version);
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see org.onap.policy.apex.auth.api.ApexEditorAPI#validateContextSchemas(java.lang.String,
+     * java.lang.String)
+     */
+    @Override
+    public ApexAPIResult validateContextSchemas(final String name, final String version) {
+        return contextSchemaFacade.validateContextSchemas(name, version);
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see org.onap.policy.apex.auth.api.ApexEditorAPI#createEvent(java.lang.String,
+     * java.lang.String, java.lang.String, java.lang.String, java.lang.String, java.lang.String,
+     * java.lang.String)
+     */
+    @Override
+    public ApexAPIResult createEvent(final String name, final String version, final String nameSpace,
+            final String source, final String target, final String uuid, final String description) {
+        return eventFacade.createEvent(name, version, nameSpace, source, target, uuid, description);
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see org.onap.policy.apex.auth.api.ApexEditorAPI#updateEvent(java.lang.String,
+     * java.lang.String, java.lang.String, java.lang.String, java.lang.String, java.lang.String,
+     * java.lang.String)
+     */
+    @Override
+    public ApexAPIResult updateEvent(final String name, final String version, final String nameSpace,
+            final String source, final String target, final String uuid, final String description) {
+        return eventFacade.updateEvent(name, version, nameSpace, source, target, uuid, description);
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see org.onap.policy.apex.auth.api.ApexEditorAPI#listEvent(java.lang.String,
+     * java.lang.String)
+     */
+    @Override
+    public ApexAPIResult listEvent(final String name, final String version) {
+        return eventFacade.listEvent(name, version);
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see org.onap.policy.apex.auth.api.ApexEditorAPI#deleteEvent(java.lang.String,
+     * java.lang.String)
+     */
+    @Override
+    public ApexAPIResult deleteEvent(final String name, final String version) {
+        return eventFacade.deleteEvent(name, version);
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see org.onap.policy.apex.auth.api.ApexEditorAPI#validateEvent(java.lang.String,
+     * java.lang.String)
+     */
+    @Override
+    public ApexAPIResult validateEvent(final String name, final String version) {
+        return eventFacade.validateEvent(name, version);
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see org.onap.policy.apex.model.modelapi.ApexEditorAPI#createEventPar(java.lang.String,
+     * java.lang.String, java.lang.String, java.lang.String, java.lang.String, boolean)
+     */
+    @Override
+    public ApexAPIResult createEventPar(final String name, final String version, final String parName,
+            final String contextSchemaName, final String contextSchemaVersion, final boolean optional) {
+        return eventFacade.createEventPar(name, version, parName, contextSchemaName, contextSchemaVersion, optional);
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see org.onap.policy.apex.auth.api.ApexEditorAPI#listEventPar(java.lang.String,
+     * java.lang.String, java.lang.String)
+     */
+    @Override
+    public ApexAPIResult listEventPar(final String name, final String version, final String parName) {
+        return eventFacade.listEventPar(name, version, parName);
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see org.onap.policy.apex.auth.api.ApexEditorAPI#deleteEventPar(java.lang.String,
+     * java.lang.String, java.lang.String)
+     */
+    @Override
+    public ApexAPIResult deleteEventPar(final String name, final String version, final String parName) {
+        return eventFacade.deleteEventPar(name, version, parName);
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see org.onap.policy.apex.model.modelapi.ApexEditorAPI#createContextAlbum(java.lang.String,
+     * java.lang.String, java.lang.String, java.lang.String, java.lang.String, java.lang.String,
+     * java.lang.String, java.lang.String)
+     */
+    @Override
+    // CHECKSTYLE:OFF: checkstyle:parameterNumber
+    public ApexAPIResult createContextAlbum(final String name, final String version, final String scope,
+            final String writable, final String contextSchemaName, final String contextSchemaVersion, final String uuid,
+            final String description) {
+        return contextAlbumFacade.createContextAlbum(name, version, scope, writable, contextSchemaName,
+                contextSchemaVersion, uuid, description);
+    }
+    // CHECKSTYLE:ON: checkstyle:parameterNumber
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see org.onap.policy.apex.model.modelapi.ApexEditorAPI#updateContextAlbum(java.lang.String,
+     * java.lang.String, java.lang.String, java.lang.String, java.lang.String, java.lang.String,
+     * java.lang.String, java.lang.String)
+     */
+    // CHECKSTYLE:OFF: checkstyle:parameterNumber
+    @Override
+    public ApexAPIResult updateContextAlbum(final String name, final String version, final String scope,
+            final String writable, final String contextSchemaName, final String contextSchemaVersion, final String uuid,
+            final String description) {
+        return contextAlbumFacade.updateContextAlbum(name, version, scope, writable, contextSchemaName,
+                contextSchemaVersion, uuid, description);
+    }
+    // CHECKSTYLE:ON: checkstyle:parameterNumber
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see org.onap.policy.apex.auth.api.ApexEditorAPI#listContextAlbum(java.lang.String,
+     * java.lang.String)
+     */
+    @Override
+    public ApexAPIResult listContextAlbum(final String name, final String version) {
+        return contextAlbumFacade.listContextAlbum(name, version);
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see org.onap.policy.apex.auth.api.ApexEditorAPI#deleteContextAlbum(java.lang.String,
+     * java.lang.String)
+     */
+    @Override
+    public ApexAPIResult deleteContextAlbum(final String name, final String version) {
+        return contextAlbumFacade.deleteContextAlbum(name, version);
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see org.onap.policy.apex.auth.api.ApexEditorAPI#validateContextAlbum(java.lang.String,
+     * java.lang.String)
+     */
+    @Override
+    public ApexAPIResult validateContextAlbum(final String name, final String version) {
+        return contextAlbumFacade.validateContextAlbum(name, version);
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see org.onap.policy.apex.auth.api.ApexEditorAPI#createTask(java.lang.String,
+     * java.lang.String, java.lang.String, java.lang.String)
+     */
+    @Override
+    public ApexAPIResult createTask(final String name, final String version, final String uuid,
+            final String description) {
+        return taskFacade.createTask(name, version, uuid, description);
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see org.onap.policy.apex.auth.api.ApexEditorAPI#updateTask(java.lang.String,
+     * java.lang.String, java.lang.String, java.lang.String)
+     */
+    @Override
+    public ApexAPIResult updateTask(final String name, final String version, final String uuid,
+            final String description) {
+        return taskFacade.updateTask(name, version, uuid, description);
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see org.onap.policy.apex.auth.api.ApexEditorAPI#listTask(java.lang.String, java.lang.String)
+     */
+    @Override
+    public ApexAPIResult listTask(final String name, final String version) {
+        return taskFacade.listTask(name, version);
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see org.onap.policy.apex.auth.api.ApexEditorAPI#deleteTask(java.lang.String,
+     * java.lang.String)
+     */
+    @Override
+    public ApexAPIResult deleteTask(final String name, final String version) {
+        return taskFacade.deleteTask(name, version);
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see org.onap.policy.apex.auth.api.ApexEditorAPI#validateTask(java.lang.String,
+     * java.lang.String)
+     */
+    @Override
+    public ApexAPIResult validateTask(final String name, final String version) {
+        return taskFacade.validateTask(name, version);
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see org.onap.policy.apex.auth.api.ApexEditorAPI#createTaskLogic(java.lang.String,
+     * java.lang.String, java.lang.String, java.lang.String)
+     */
+    @Override
+    public ApexAPIResult createTaskLogic(final String name, final String version, final String logicFlavour,
+            final String logic) {
+        return taskFacade.createTaskLogic(name, version, logicFlavour, logic);
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see org.onap.policy.apex.auth.api.ApexEditorAPI#updateTaskLogic(java.lang.String,
+     * java.lang.String, java.lang.String, java.lang.String)
+     */
+    @Override
+    public ApexAPIResult updateTaskLogic(final String name, final String version, final String logicFlavour,
+            final String logic) {
+        return taskFacade.updateTaskLogic(name, version, logicFlavour, logic);
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see org.onap.policy.apex.auth.api.ApexEditorAPI#listTaskLogic(java.lang.String,
+     * java.lang.String)
+     */
+    @Override
+    public ApexAPIResult listTaskLogic(final String name, final String version) {
+        return taskFacade.listTaskLogic(name, version);
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see org.onap.policy.apex.auth.api.ApexEditorAPI#deleteTaskLogic(java.lang.String,
+     * java.lang.String)
+     */
+    @Override
+    public ApexAPIResult deleteTaskLogic(final String name, final String version) {
+        return taskFacade.deleteTaskLogic(name, version);
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see org.onap.policy.apex.auth.api.ApexEditorAPI#createTaskInputField(java.lang.String,
+     * java.lang.String, java.lang.String, java.lang.String, java.lang.String, java.lang.boolean)
+     */
+    @Override
+    public ApexAPIResult createTaskInputField(final String name, final String version, final String fieldName,
+            final String dataTypeName, final String dataTypeVersion, final boolean optional) {
+        return taskFacade.createTaskInputField(name, version, fieldName, dataTypeName, dataTypeVersion, optional);
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see org.onap.policy.apex.auth.api.ApexEditorAPI#listTaskInputField(java.lang.String,
+     * java.lang.String, java.lang.String)
+     */
+    @Override
+    public ApexAPIResult listTaskInputField(final String name, final String version, final String fieldName) {
+        return taskFacade.listTaskInputField(name, version, fieldName);
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see org.onap.policy.apex.auth.api.ApexEditorAPI#deleteTaskInputField(java.lang.String,
+     * java.lang.String, java.lang.String)
+     */
+    @Override
+    public ApexAPIResult deleteTaskInputField(final String name, final String version, final String fieldName) {
+        return taskFacade.deleteTaskInputField(name, version, fieldName);
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see org.onap.policy.apex.auth.api.ApexEditorAPI#createTaskOutputField(java.lang.String,
+     * java.lang.String, java.lang.String, java.lang.String, java.lang.String, java.lang.boolean)
+     */
+    @Override
+    public ApexAPIResult createTaskOutputField(final String name, final String version, final String fieldName,
+            final String dataTypeName, final String dataTypeVersion, final boolean optional) {
+        return taskFacade.createTaskOutputField(name, version, fieldName, dataTypeName, dataTypeVersion, optional);
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see org.onap.policy.apex.auth.api.ApexEditorAPI#listTaskOutputField(java.lang.String,
+     * java.lang.String, java.lang.String)
+     */
+    @Override
+    public ApexAPIResult listTaskOutputField(final String name, final String version, final String fieldName) {
+        return taskFacade.listTaskOutputField(name, version, fieldName);
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see org.onap.policy.apex.auth.api.ApexEditorAPI#deleteTaskOutputField(java.lang.String,
+     * java.lang.String, java.lang.String)
+     */
+    @Override
+    public ApexAPIResult deleteTaskOutputField(final String name, final String version, final String fieldName) {
+        return taskFacade.deleteTaskOutputField(name, version, fieldName);
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see org.onap.policy.apex.auth.api.ApexEditorAPI#createTaskParameter(java.lang.String,
+     * java.lang.String, java.lang.String, java.lang.String)
+     */
+    @Override
+    public ApexAPIResult createTaskParameter(final String name, final String version, final String parName,
+            final String defaultValue) {
+        return taskFacade.createTaskParameter(name, version, parName, defaultValue);
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see org.onap.policy.apex.auth.api.ApexEditorAPI#listTaskParameter(java.lang.String,
+     * java.lang.String, java.lang.String)
+     */
+    @Override
+    public ApexAPIResult listTaskParameter(final String name, final String version, final String parName) {
+        return taskFacade.listTaskParameter(name, version, parName);
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see org.onap.policy.apex.auth.api.ApexEditorAPI#deleteTaskParameter(java.lang.String,
+     * java.lang.String, java.lang.String)
+     */
+    @Override
+    public ApexAPIResult deleteTaskParameter(final String name, final String version, final String parName) {
+        return taskFacade.deleteTaskParameter(name, version, parName);
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see org.onap.policy.apex.auth.api.ApexEditorAPI#createTaskContextRef(java.lang.String,
+     * java.lang.String, java.lang.String, java.lang.String)
+     */
+    @Override
+    public ApexAPIResult createTaskContextRef(final String name, final String version, final String contextAlbumName,
+            final String contextAlbumVersion) {
+        return taskFacade.createTaskContextRef(name, version, contextAlbumName, contextAlbumVersion);
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see org.onap.policy.apex.auth.api.ApexEditorAPI#listTaskContextRef(java.lang.String,
+     * java.lang.String, java.lang.String, java.lang.String)
+     */
+    @Override
+    public ApexAPIResult listTaskContextRef(final String name, final String version, final String contextAlbumName,
+            final String contextAlbumVersion) {
+        return taskFacade.listTaskContextRef(name, version, contextAlbumName, contextAlbumVersion);
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see org.onap.policy.apex.auth.api.ApexEditorAPI#deleteTaskContextRef(java.lang.String,
+     * java.lang.String, java.lang.String, java.lang.String)
+     */
+    @Override
+    public ApexAPIResult deleteTaskContextRef(final String name, final String version, final String contextAlbumName,
+            final String contextAlbumVersion) {
+        return taskFacade.deleteTaskContextRef(name, version, contextAlbumName, contextAlbumVersion);
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see org.onap.policy.apex.auth.api.ApexEditorAPI#createPolicy(java.lang.String,
+     * java.lang.String, java.lang.String, java.lang.String, java.lang.String, java.lang.String)
+     */
+    @Override
+    public ApexAPIResult createPolicy(final String name, final String version, final String template,
+            final String firstState, final String uuid, final String description) {
+        return policyFacade.createPolicy(name, version, template, firstState, uuid, description);
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see org.onap.policy.apex.auth.api.ApexEditorAPI#updatePolicy(java.lang.String,
+     * java.lang.String, java.lang.String, java.lang.String, java.lang.String, java.lang.String)
+     */
+    @Override
+    public ApexAPIResult updatePolicy(final String name, final String version, final String template,
+            final String firstState, final String uuid, final String description) {
+        return policyFacade.updatePolicy(name, version, template, firstState, uuid, description);
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see org.onap.policy.apex.auth.api.ApexEditorAPI#listPolicy(java.lang.String,
+     * java.lang.String)
+     */
+    @Override
+    public ApexAPIResult listPolicy(final String name, final String version) {
+        return policyFacade.listPolicy(name, version);
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see org.onap.policy.apex.auth.api.ApexEditorAPI#deletePolicy(java.lang.String,
+     * java.lang.String)
+     */
+    @Override
+    public ApexAPIResult deletePolicy(final String name, final String version) {
+        return policyFacade.deletePolicy(name, version);
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see org.onap.policy.apex.auth.api.ApexEditorAPI#validatePolicy(java.lang.String,
+     * java.lang.String)
+     */
+    @Override
+    public ApexAPIResult validatePolicy(final String name, final String version) {
+        return policyFacade.validatePolicy(name, version);
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see org.onap.policy.apex.auth.api.ApexEditorAPI#createPolicyState(java.lang.String,
+     * java.lang.String, java.lang.String, java.lang.String, java.lang.String, java.lang.String,
+     * java.lang.String)
+     */
+    @Override
+    public ApexAPIResult createPolicyState(final String name, final String version, final String stateName,
+            final String triggerName, final String triggerVersion, final String defaultTaskName,
+            final String defaltTaskVersion) {
+        return policyFacade.createPolicyState(name, version, stateName, triggerName, triggerVersion, defaultTaskName,
+                defaltTaskVersion);
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see org.onap.policy.apex.auth.api.ApexEditorAPI#updatePolicyState(java.lang.String,
+     * java.lang.String, java.lang.String, java.lang.String, java.lang.String, java.lang.String,
+     * java.lang.String)
+     */
+    @Override
+    public ApexAPIResult updatePolicyState(final String name, final String version, final String stateName,
+            final String triggerName, final String triggerVersion, final String defaultTaskName,
+            final String defaltTaskVersion) {
+        return policyFacade.updatePolicyState(name, version, stateName, triggerName, triggerVersion, defaultTaskName,
+                defaltTaskVersion);
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see org.onap.policy.apex.auth.api.ApexEditorAPI#listPolicyState(java.lang.String,
+     * java.lang.String, java.lang.String)
+     */
+    @Override
+    public ApexAPIResult listPolicyState(final String name, final String version, final String stateName) {
+        return policyFacade.listPolicyState(name, version, stateName);
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see org.onap.policy.apex.auth.api.ApexEditorAPI#deletePolicyState(java.lang.String,
+     * java.lang.String, java.lang.String)
+     */
+    @Override
+    public ApexAPIResult deletePolicyState(final String name, final String version, final String stateName) {
+        return policyFacade.deletePolicyState(name, version, stateName);
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see
+     * org.onap.policy.apex.auth.api.ApexEditorAPI#createPolicyStateTaskSelectionLogic(java.lang.
+     * String, java.lang.String, java.lang.String, java.lang.String, java.lang.String)
+     */
+    @Override
+    public ApexAPIResult createPolicyStateTaskSelectionLogic(final String name, final String version,
+            final String stateName, final String logicFlavour, final String logic) {
+        return policyFacade.createPolicyStateTaskSelectionLogic(name, version, stateName, logicFlavour, logic);
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see
+     * org.onap.policy.apex.auth.api.ApexEditorAPI#updatePolicyStateTaskSelectionLogic(java.lang.
+     * String, java.lang.String, java.lang.String, java.lang.String, java.lang.String)
+     */
+    @Override
+    public ApexAPIResult updatePolicyStateTaskSelectionLogic(final String name, final String version,
+            final String stateName, final String logicFlavour, final String logic) {
+        return policyFacade.updatePolicyStateTaskSelectionLogic(name, version, stateName, logicFlavour, logic);
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see org.onap.policy.apex.auth.api.ApexEditorAPI#listPolicyStateTaskSelectionLogic(java.lang.
+     * String, java.lang.String, java.lang.String)
+     */
+    @Override
+    public ApexAPIResult listPolicyStateTaskSelectionLogic(final String name, final String version,
+            final String stateName) {
+        return policyFacade.listPolicyStateTaskSelectionLogic(name, version, stateName);
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see
+     * org.onap.policy.apex.auth.api.ApexEditorAPI#deletePolicyStateTaskSelectionLogic(java.lang.
+     * String, java.lang.String, java.lang.String)
+     */
+    @Override
+    public ApexAPIResult deletePolicyStateTaskSelectionLogic(final String name, final String version,
+            final String stateName) {
+        return policyFacade.deletePolicyStateTaskSelectionLogic(name, version, stateName);
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see org.onap.policy.apex.auth.api.ApexEditorAPI#createPolicyStateOutput(java.lang.String,
+     * java.lang.String, java.lang.String, java.lang.String, java.lang.String, java.lang.String,
+     * java.lang.String)
+     */
+    @Override
+    public ApexAPIResult createPolicyStateOutput(final String name, final String version, final String stateName,
+            final String outputName, final String eventName, final String eventVersion, final String nextState) {
+        return policyFacade.createPolicyStateOutput(name, version, stateName, outputName, eventName, eventVersion,
+                nextState);
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see org.onap.policy.apex.auth.api.ApexEditorAPI#listPolicyStateOutput(java.lang.String,
+     * java.lang.String, java.lang.String, java.lang.String)
+     */
+    @Override
+    public ApexAPIResult listPolicyStateOutput(final String name, final String version, final String stateName,
+            final String outputName) {
+        return policyFacade.listPolicyStateOutput(name, version, stateName, outputName);
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see org.onap.policy.apex.auth.api.ApexEditorAPI#deletePolicyStateOutput(java.lang.String,
+     * java.lang.String, java.lang.String, java.lang.String)
+     */
+    @Override
+    public ApexAPIResult deletePolicyStateOutput(final String name, final String version, final String stateName,
+            final String outputName) {
+        return policyFacade.deletePolicyStateOutput(name, version, stateName, outputName);
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see
+     * org.onap.policy.apex.core.modelapi.ApexEditorAPI#createPolicyStateFinalizerLogic(java.lang.
+     * String, java.lang.String, java.lang.String, java.lang.String, java.lang.String,
+     * java.lang.String)
+     */
+    @Override
+    public ApexAPIResult createPolicyStateFinalizerLogic(final String name, final String version,
+            final String stateName, final String finalizerLogicName, final String logicFlavour, final String logic) {
+        return policyFacade.createPolicyStateFinalizerLogic(name, version, stateName, finalizerLogicName, logicFlavour,
+                logic);
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see
+     * org.onap.policy.apex.core.modelapi.ApexEditorAPI#updatePolicyStateFinalizerLogic(java.lang.
+     * String, java.lang.String, java.lang.String, java.lang.String, java.lang.String,
+     * java.lang.String)
+     */
+    @Override
+    public ApexAPIResult updatePolicyStateFinalizerLogic(final String name, final String version,
+            final String stateName, final String finalizerLogicName, final String logicFlavour, final String logic) {
+        return policyFacade.updatePolicyStateFinalizerLogic(name, version, stateName, finalizerLogicName, logicFlavour,
+                logic);
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see
+     * org.onap.policy.apex.core.modelapi.ApexEditorAPI#listPolicyStateFinalizerLogic(java.lang.
+     * String, java.lang.String, java.lang.String, java.lang.String)
+     */
+    @Override
+    public ApexAPIResult listPolicyStateFinalizerLogic(final String name, final String version, final String stateName,
+            final String finalizerLogicName) {
+        return policyFacade.listPolicyStateFinalizerLogic(name, version, stateName, finalizerLogicName);
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see
+     * org.onap.policy.apex.core.modelapi.ApexEditorAPI#deletePolicyStateFinalizerLogic(java.lang.
+     * String, java.lang.String, java.lang.String, java.lang.String)
+     */
+    @Override
+    public ApexAPIResult deletePolicyStateFinalizerLogic(final String name, final String version,
+            final String stateName, final String finalizerLogicName) {
+        return policyFacade.deletePolicyStateFinalizerLogic(name, version, stateName, finalizerLogicName);
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see
+     * org.onap.policy.apex.core.modelapi.ApexEditorAPI#createPolicyStateTaskRef(java.lang.String,
+     * java.lang.String, java.lang.String, java.lang.String, java.lang.String, java.lang.String,
+     * java.lang.String, java.lang.String)
+     */
+    @Override
+    // CHECKSTYLE:OFF: checkstyle:parameterNumber
+    public ApexAPIResult createPolicyStateTaskRef(final String name, final String version, final String stateName,
+            final String taskLocalName, final String taskName, final String taskVersion, final String outputType,
+            final String outputName) {
+        return policyFacade.createPolicyStateTaskRef(name, version, stateName, taskLocalName, taskName, taskVersion,
+                outputType, outputName);
+    }
+    // CHECKSTYLE:ON: checkstyle:parameterNumber
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see org.onap.policy.apex.auth.api.ApexEditorAPI#listPolicyStateTaskRef(java.lang.String,
+     * java.lang.String, java.lang.String, java.lang.String, java.lang.String)
+     */
+    @Override
+    public ApexAPIResult listPolicyStateTaskRef(final String name, final String version, final String stateName,
+            final String taskName, final String taskVersion) {
+        return policyFacade.listPolicyStateTaskRef(name, version, stateName, taskName, taskVersion);
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see org.onap.policy.apex.auth.api.ApexEditorAPI#deletePolicyStateTaskRef(java.lang.String,
+     * java.lang.String, java.lang.String, java.lang.String, java.lang.String)
+     */
+    @Override
+    public ApexAPIResult deletePolicyStateTaskRef(final String name, final String version, final String stateName,
+            final String taskName, final String taskVersion) {
+        return policyFacade.deletePolicyStateTaskRef(name, version, stateName, taskName, taskVersion);
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see
+     * org.onap.policy.apex.auth.api.ApexEditorAPI#createPolicyStateContextRef(java.lang.String,
+     * java.lang.String, java.lang.String, java.lang.String, java.lang.String)
+     */
+    @Override
+    public ApexAPIResult createPolicyStateContextRef(final String name, final String version, final String stateName,
+            final String contextAlbumName, final String contextAlbumVersion) {
+        return policyFacade.createPolicyStateContextRef(name, version, stateName, contextAlbumName,
+                contextAlbumVersion);
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see org.onap.policy.apex.auth.api.ApexEditorAPI#listPolicyStateContextRef(java.lang.String,
+     * java.lang.String, java.lang.String, java.lang.String, java.lang.String)
+     */
+    @Override
+    public ApexAPIResult listPolicyStateContextRef(final String name, final String version, final String stateName,
+            final String contextAlbumName, final String contextAlbumVersion) {
+        return policyFacade.listPolicyStateContextRef(name, version, stateName, contextAlbumName, contextAlbumVersion);
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see
+     * org.onap.policy.apex.auth.api.ApexEditorAPI#deletePolicyStateContextRef(java.lang.String,
+     * java.lang.String, java.lang.String, java.lang.String, java.lang.String)
+     */
+    @Override
+    public ApexAPIResult deletePolicyStateContextRef(final String name, final String version, final String stateName,
+            final String contextAlbumName, final String contextAlbumVersion) {
+        return policyFacade.deletePolicyStateContextRef(name, version, stateName, contextAlbumName,
+                contextAlbumVersion);
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see org.onap.policy.apex.core.modelapi.ApexModel#loadFromString(java.lang.String)
+     */
+    @Override
+    public ApexAPIResult loadFromString(final String modelString) {
+        return modelHandlerFacade.loadFromString(modelString);
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see org.onap.policy.apex.auth.api.ApexModel#loadFromFile(java.lang.String)
+     */
+    @Override
+    // CHECKSTYLE:OFF: checkstyle:HiddenField
+    public ApexAPIResult loadFromFile(final String fileName) {
+        this.fileName = fileName;
+        return modelHandlerFacade.loadFromFile(fileName);
+    }
+    // CHECKSTYLE:ON: checkstyle:HiddenField
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see org.onap.policy.apex.auth.api.ApexModel#saveToFile(java.lang.String, boolean)
+     */
+    @Override
+    public ApexAPIResult saveToFile(final String saveFileName, final boolean xmlFlag) {
+        if (saveFileName == null) {
+            return modelHandlerFacade.saveToFile(fileName, xmlFlag);
+        } else {
+            return modelHandlerFacade.saveToFile(saveFileName, xmlFlag);
+        }
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see org.onap.policy.apex.model.modelapi.ApexModel#loadFromDatabase(java.lang.String,
+     * java.lang.String, org.onap.policy.apex.model.basicmodel.dao.DAOParameters)
+     */
+    @Override
+    public ApexAPIResult loadFromDatabase(final String modelName, final String modelVersion,
+            final DAOParameters daoParameters) {
+        return modelHandlerFacade.loadFromDatabase(modelName, modelVersion, daoParameters);
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see org.onap.policy.apex.model.modelapi.ApexModel#saveToDatabase(org.onap.policy.apex.model.
+     * basicmodel. dao.DAOParameters)
+     */
+    @Override
+    public ApexAPIResult saveToDatabase(final DAOParameters daoParameters) {
+        return modelHandlerFacade.saveToDatabase(daoParameters);
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see org.onap.policy.apex.auth.api.ApexModel#readFromURL(java.lang.String)
+     */
+    @Override
+    public ApexAPIResult readFromURL(final String urlString) {
+        return modelHandlerFacade.readFromURL(urlString);
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see org.onap.policy.apex.auth.api.ApexModel#writeToURL(java.lang.String, boolean)
+     */
+    @Override
+    public ApexAPIResult writeToURL(final String urlString, final boolean xmlFlag) {
+        return modelHandlerFacade.writeToURL(urlString, xmlFlag);
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see org.onap.policy.apex.auth.api.ApexModel#analyse()
+     */
+    @Override
+    public ApexAPIResult analyse() {
+        return modelHandlerFacade.analyse();
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see org.onap.policy.apex.auth.api.ApexModel#validate()
+     */
+    @Override
+    public ApexAPIResult validate() {
+        return modelHandlerFacade.validate();
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see org.onap.policy.apex.auth.api.ApexModel#compare(java.lang.String, boolean, boolean)
+     */
+    @Override
+    public ApexAPIResult compare(final String otherModelFileName, final boolean diffsOnly, final boolean keysOnly) {
+        return modelHandlerFacade.compare(otherModelFileName, diffsOnly, keysOnly);
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see org.onap.policy.apex.core.modelapi.ApexModel#compareWithString(java.lang.String,
+     * boolean, boolean)
+     */
+    @Override
+    public ApexAPIResult compareWithString(final String otherModelString, final boolean diffsOnly,
+            final boolean keysOnly) {
+        return modelHandlerFacade.compareWithString(otherModelString, diffsOnly, keysOnly);
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see org.onap.policy.apex.auth.api.ApexModel#split(java.lang.String, java.lang.String)
+     */
+    @Override
+    public ApexAPIResult split(final String targetModelFileName, final String splitOutPolicies) {
+        return modelHandlerFacade.split(targetModelFileName, splitOutPolicies);
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see org.onap.policy.apex.core.modelapi.ApexModel#split(java.lang.String)
+     */
+    @Override
+    public ApexAPIResult split(final String splitOutPolicies) {
+        return modelHandlerFacade.split(splitOutPolicies);
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see org.onap.policy.apex.auth.api.ApexModel#merge(java.lang.String, boolean)
+     */
+    @Override
+    public ApexAPIResult merge(final String mergeInModelFileName, final boolean keepOriginal) {
+        return modelHandlerFacade.merge(mergeInModelFileName, keepOriginal);
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see org.onap.policy.apex.core.modelapi.ApexModel#mergeWithString(java.lang.String, boolean)
+     */
+    @Override
+    public ApexAPIResult mergeWithString(final String otherModelString, final boolean keepOriginal) {
+        return modelHandlerFacade.mergeWithString(otherModelString, keepOriginal);
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see java.lang.Object#hashCode()
+     */
+    @Override
+    public int hashCode() {
+        final int prime = HASH_CODE_PRIME_0;
+        int result = 1;
+        result = prime * result + ((apexProperties == null) ? 0 : apexProperties.hashCode());
+        result = prime * result + ((contextAlbumFacade == null) ? 0 : contextAlbumFacade.hashCode());
+        result = prime * result + ((contextSchemaFacade == null) ? 0 : contextSchemaFacade.hashCode());
+        result = prime * result + ((eventFacade == null) ? 0 : eventFacade.hashCode());
+        result = prime * result + ((fileName == null) ? 0 : fileName.hashCode());
+        result = prime * result + (jsonMode ? HASH_CODE_PRIME_1 : HASH_CODE_PRIME_2);
+        result = prime * result + ((keyInformationFacade == null) ? 0 : keyInformationFacade.hashCode());
+        result = prime * result + ((modelFacade == null) ? 0 : modelFacade.hashCode());
+        result = prime * result + ((modelHandlerFacade == null) ? 0 : modelHandlerFacade.hashCode());
+        result = prime * result + ((policyFacade == null) ? 0 : policyFacade.hashCode());
+        result = prime * result + ((policyModel == null) ? 0 : policyModel.hashCode());
+        result = prime * result + ((taskFacade == null) ? 0 : taskFacade.hashCode());
+        return result;
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see org.onap.policy.apex.auth.api.ApexModel#getModel()
+     */
+    @Override
+    public AxPolicyModel getPolicyModel() {
+        return policyModel;
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see
+     * org.onap.policy.apex.auth.api.ApexModel#setPolicyModel(org.onap.policy.apex.core.policymodel.
+     * concepts.AxPolicyModel)
+     */
+    @Override
+    public void setPolicyModel(final AxPolicyModel policyModel) {
+        this.policyModel = policyModel;
+    }
+
+    /*
+     * (non-Javadoc)
+     *
+     * @see org.onap.policy.apex.core.modelapi.ApexModel#build()
+     */
+    @Override
+    public AxPolicyModel build() {
+        return policyModel;
+    }
+
+}
diff --git a/model/model-api/src/main/java/org/onap/policy/apex/model/modelapi/impl/ContextAlbumFacade.java b/model/model-api/src/main/java/org/onap/policy/apex/model/modelapi/impl/ContextAlbumFacade.java
new file mode 100644
index 000000000..57d05025a
--- /dev/null
+++ b/model/model-api/src/main/java/org/onap/policy/apex/model/modelapi/impl/ContextAlbumFacade.java
@@ -0,0 +1,282 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2016-2018 Ericsson. 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 or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * 
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.model.modelapi.impl;
+
+import java.util.Properties;
+import java.util.Set;
+
+import org.onap.policy.apex.model.basicmodel.concepts.AxArtifactKey;
+import org.onap.policy.apex.model.basicmodel.concepts.AxValidationResult;
+import org.onap.policy.apex.model.basicmodel.handling.ApexModelStringWriter;
+import org.onap.policy.apex.model.contextmodel.concepts.AxContextAlbum;
+import org.onap.policy.apex.model.contextmodel.concepts.AxContextSchema;
+import org.onap.policy.apex.model.modelapi.ApexAPIResult;
+import org.onap.policy.apex.model.modelapi.ApexModel;
+
+/**
+ * This class acts as a facade for operations towards a policy model for context album operations.
+ *
+ * @author Liam Fallon (liam.fallon@ericsson.com)
+ */
+public class ContextAlbumFacade {
+    private static final String CONCEPT = "concept ";
+    private static final String CONCEPT_S = "concept(s) ";
+    private static final String DOES_NOT_EXIST = " does not exist";
+    private static final String DO_ES_NOT_EXIST = " do(es) not exist";
+
+    // Apex model we're working towards
+    private final ApexModel apexModel;
+
+    // Properties to use for the model
+    private final Properties apexProperties;
+
+    // Facade classes for working towards the real Apex model
+    private final KeyInformationFacade keyInformationFacade;
+
+    // JSON output on list/delete if set
+    private final boolean jsonMode;
+
+    /**
+     * Constructor that creates a context album facade for the Apex Model API.
+     *
+     * @param apexModel the apex model
+     * @param apexProperties Properties for the model
+     * @param jsonMode set to true to return JSON strings in list and delete operations, otherwise
+     *        set to false
+     */
+    public ContextAlbumFacade(final ApexModel apexModel, final Properties apexProperties, final boolean jsonMode) {
+        this.apexModel = apexModel;
+        this.apexProperties = apexProperties;
+        this.jsonMode = jsonMode;
+
+        keyInformationFacade = new KeyInformationFacade(apexModel, apexProperties, jsonMode);
+    }
+
+    /**
+     * Create a context album.
+     *
+     * @param name name of the context album
+     * @param version version of the context album, set to null to use the default version
+     * @param scope of the context album
+     * @param writable "true" or "t" if the context album is writable, set to null or any other
+     *        value for a read-only album
+     * @param contextSchemaName name of the parameter context schema
+     * @param contextSchemaVersion version of the parameter context schema, set to null to use the
+     *        latest version
+     * @param uuid context album UUID, set to null to generate a UUID
+     * @param description context album description, set to null to generate a description
+     * @return result of the operation
+     */
+    // CHECKSTYLE:OFF: checkstyle:parameterNumber
+    public ApexAPIResult createContextAlbum(final String name, final String version, final String scope,
+            final String writable, final String contextSchemaName, final String contextSchemaVersion, final String uuid,
+            final String description) {
+        try {
+            final AxArtifactKey key = new AxArtifactKey();
+            key.setName(name);
+            if (version != null) {
+                key.setVersion(version);
+            } else {
+                key.setVersion(apexProperties.getProperty("DEFAULT_CONCEPT_VERSION"));
+            }
+
+            if (apexModel.getPolicyModel().getAlbums().getAlbumsMap().containsKey(key)) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_EXISTS,
+                        CONCEPT + key.getID() + " already exists");
+            }
+
+            final AxContextSchema schema =
+                    apexModel.getPolicyModel().getSchemas().get(contextSchemaName, contextSchemaVersion);
+            if (schema == null) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                        CONCEPT + contextSchemaName + ':' + contextSchemaVersion + DOES_NOT_EXIST);
+            }
+
+            final AxContextAlbum contextAlbum = new AxContextAlbum(key);
+            contextAlbum.setScope(scope);
+            contextAlbum.setItemSchema(schema.getKey());
+
+            if (writable != null
+                    && (writable.trim().equalsIgnoreCase("true") || writable.trim().equalsIgnoreCase("t"))) {
+                contextAlbum.setWritable(true);
+            } else {
+                contextAlbum.setWritable(false);
+            }
+
+            apexModel.getPolicyModel().getAlbums().getAlbumsMap().put(key, contextAlbum);
+
+            if (apexModel.getPolicyModel().getKeyInformation().getKeyInfoMap().containsKey(key)) {
+                return keyInformationFacade.updateKeyInformation(name, version, uuid, description);
+            } else {
+                return keyInformationFacade.createKeyInformation(name, version, uuid, description);
+            }
+        } catch (final Exception e) {
+            return new ApexAPIResult(ApexAPIResult.RESULT.FAILED, e);
+        }
+    }
+    // CHECKSTYLE:ON: checkstyle:parameterNumber
+
+    /**
+     * Update a context album.
+     *
+     * @param name name of the context album
+     * @param version version of the context album, set to null to use the default version
+     * @param scope of the context album
+     * @param writable "true" or "t" if the context album is writable, set to null or any other
+     *        value for a read-only album
+     * @param contextSchemaName name of the parameter context schema
+     * @param contextSchemaVersion version of the parameter context schema, set to null to use the
+     *        latest version
+     * @param uuid context album UUID, set to null to generate a UUID
+     * @param description context album description, set to null to generate a description
+     * @return result of the operation
+     */
+    // CHECKSTYLE:OFF: checkstyle:parameterNumber
+    public ApexAPIResult updateContextAlbum(final String name, final String version, final String scope,
+            final String writable, final String contextSchemaName, final String contextSchemaVersion, final String uuid,
+            final String description) {
+        try {
+            final AxContextAlbum contextAlbum = apexModel.getPolicyModel().getAlbums().get(name, version);
+            if (contextAlbum == null) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                        CONCEPT + name + ':' + version + DOES_NOT_EXIST);
+            }
+
+            if (scope != null) {
+                contextAlbum.setScope(scope);
+            }
+            if (writable != null) {
+                if (writable.trim().equalsIgnoreCase("true") || writable.trim().equalsIgnoreCase("t")) {
+                    contextAlbum.setWritable(true);
+                } else {
+                    contextAlbum.setWritable(false);
+                }
+            }
+
+            if (contextSchemaName != null) {
+                final AxContextSchema schema =
+                        apexModel.getPolicyModel().getSchemas().get(contextSchemaName, contextSchemaVersion);
+                if (schema == null) {
+                    return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                            CONCEPT + contextSchemaName + ':' + contextSchemaVersion + DOES_NOT_EXIST);
+                }
+                contextAlbum.setItemSchema(schema.getKey());
+            }
+
+            return keyInformationFacade.updateKeyInformation(name, version, uuid, description);
+        } catch (final Exception e) {
+            return new ApexAPIResult(ApexAPIResult.RESULT.FAILED, e);
+        }
+    }
+    // CHECKSTYLE:ON: checkstyle:parameterNumber
+
+    /**
+     * List context albums.
+     *
+     * @param name name of the context album, set to null to list all
+     * @param version starting version of the context album, set to null to list all versions
+     * @return result of the operation
+     */
+    public ApexAPIResult listContextAlbum(final String name, final String version) {
+        try {
+            final Set<AxContextAlbum> contextAlbumSet = apexModel.getPolicyModel().getAlbums().getAll(name, version);
+            if (name != null && contextAlbumSet.isEmpty()) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                        CONCEPT_S + name + ':' + version + DO_ES_NOT_EXIST);
+            }
+
+            final ApexAPIResult result = new ApexAPIResult();
+            for (final AxContextAlbum contextAlbum : contextAlbumSet) {
+                result.addMessage(new ApexModelStringWriter<AxContextAlbum>(false).writeString(contextAlbum,
+                        AxContextAlbum.class, jsonMode));
+            }
+            return result;
+        } catch (final Exception e) {
+            return new ApexAPIResult(ApexAPIResult.RESULT.FAILED, e);
+        }
+    }
+
+    /**
+     * Delete a context album.
+     *
+     * @param name name of the context album
+     * @param version version of the context album, set to null to delete versions
+     * @return result of the operation
+     */
+    public ApexAPIResult deleteContextAlbum(final String name, final String version) {
+        try {
+            if (version != null) {
+                final AxArtifactKey key = new AxArtifactKey(name, version);
+                if (apexModel.getPolicyModel().getAlbums().getAlbumsMap().remove(key) != null) {
+                    return new ApexAPIResult();
+                } else {
+                    return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                            CONCEPT + key.getID() + DOES_NOT_EXIST);
+                }
+            }
+
+            final Set<AxContextAlbum> contextAlbumSet = apexModel.getPolicyModel().getAlbums().getAll(name, version);
+            if (contextAlbumSet.isEmpty()) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                        CONCEPT_S + name + ':' + version + DO_ES_NOT_EXIST);
+            }
+
+            final ApexAPIResult result = new ApexAPIResult();
+            for (final AxContextAlbum contextAlbum : contextAlbumSet) {
+                result.addMessage(new ApexModelStringWriter<AxContextAlbum>(false).writeString(contextAlbum,
+                        AxContextAlbum.class, jsonMode));
+                apexModel.getPolicyModel().getAlbums().getAlbumsMap().remove(contextAlbum.getKey());
+                keyInformationFacade.deleteKeyInformation(name, version);
+            }
+            return result;
+        } catch (final Exception e) {
+            return new ApexAPIResult(ApexAPIResult.RESULT.FAILED, e);
+        }
+    }
+
+    /**
+     * Validate context albums.
+     *
+     * @param name name of the context album, set to null to list all
+     * @param version starting version of the context album, set to null to list all versions
+     * @return result of the operation
+     */
+    public ApexAPIResult validateContextAlbum(final String name, final String version) {
+        try {
+            final Set<AxContextAlbum> contextAlbumSet = apexModel.getPolicyModel().getAlbums().getAll(name, version);
+            if (contextAlbumSet.isEmpty()) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                        CONCEPT_S + name + ':' + version + DO_ES_NOT_EXIST);
+            }
+
+            final ApexAPIResult result = new ApexAPIResult();
+            for (final AxContextAlbum contextAlbum : contextAlbumSet) {
+                final AxValidationResult validationResult = contextAlbum.validate(new AxValidationResult());
+                result.addMessage(new ApexModelStringWriter<AxArtifactKey>(false).writeString(contextAlbum.getKey(),
+                        AxArtifactKey.class, jsonMode));
+                result.addMessage(validationResult.toString());
+            }
+            return result;
+        } catch (final Exception e) {
+            return new ApexAPIResult(ApexAPIResult.RESULT.FAILED, e);
+        }
+    }
+}
diff --git a/model/model-api/src/main/java/org/onap/policy/apex/model/modelapi/impl/ContextSchemaFacade.java b/model/model-api/src/main/java/org/onap/policy/apex/model/modelapi/impl/ContextSchemaFacade.java
new file mode 100644
index 000000000..3f7f75652
--- /dev/null
+++ b/model/model-api/src/main/java/org/onap/policy/apex/model/modelapi/impl/ContextSchemaFacade.java
@@ -0,0 +1,240 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2016-2018 Ericsson. 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 or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * 
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.model.modelapi.impl;
+
+import java.util.Properties;
+import java.util.Set;
+
+import org.onap.policy.apex.model.basicmodel.concepts.AxArtifactKey;
+import org.onap.policy.apex.model.basicmodel.concepts.AxValidationResult;
+import org.onap.policy.apex.model.basicmodel.handling.ApexModelStringWriter;
+import org.onap.policy.apex.model.contextmodel.concepts.AxContextSchema;
+import org.onap.policy.apex.model.modelapi.ApexAPIResult;
+import org.onap.policy.apex.model.modelapi.ApexModel;
+import org.onap.policy.apex.model.utilities.Assertions;
+
+/**
+ * This class acts as a facade for operations towards a policy model for context schema operations.
+ *
+ * @author Liam Fallon (liam.fallon@ericsson.com)
+ */
+public class ContextSchemaFacade {
+	private static final String CONCEPT = "concept ";
+	private static final String CONCEPT_S = "concept(s) ";
+    private static final String DOES_NOT_EXIST = " does not exist";
+	private static final String DO_ES_NOT_EXIST = " do(es) not exist";
+	private static final String ALREADY_EXISTS = " already exists";
+
+	// Apex model we're working towards
+    private final ApexModel apexModel;
+
+    // Properties to use for the model
+    private final Properties apexProperties;
+
+    // Facade classes for working towards the real Apex model
+    private final KeyInformationFacade keyInformationFacade;
+
+    // JSON output on list/delete if set
+    private final boolean jsonMode;
+
+    /**
+     * Constructor to create the context schema facade for the Model API.
+     *
+     * @param apexModel the apex model
+     * @param apexProperties Properties for the model
+     * @param jsonMode set to true to return JSON strings in list and delete operations, otherwise set to false
+     */
+    public ContextSchemaFacade(final ApexModel apexModel, final Properties apexProperties, final boolean jsonMode) {
+        this.apexModel = apexModel;
+        this.apexProperties = apexProperties;
+        this.jsonMode = jsonMode;
+
+        keyInformationFacade = new KeyInformationFacade(apexModel, apexProperties, jsonMode);
+    }
+
+    /**
+     * Create a context schema.
+     *
+     * @param name name of the context schema
+     * @param version version of the context schema, set to null to use the default version
+     * @param schemaFlavour a string identifying the flavour of this context schema
+     * @param schemaDefinition a string containing the definition of this context schema
+     * @param uuid context schema UUID, set to null to generate a UUID
+     * @param description context schema description, set to null to generate a description
+     * @return result of the operation
+     */
+    public ApexAPIResult createContextSchema(final String name, final String version, final String schemaFlavour, final String schemaDefinition,
+            final String uuid, final String description) {
+        try {
+            Assertions.argumentNotNull(schemaFlavour, "schemaFlavour may not be null");
+
+            final AxArtifactKey key = new AxArtifactKey();
+            key.setName(name);
+            if (version != null) {
+                key.setVersion(version);
+            }
+            else {
+                key.setVersion(apexProperties.getProperty("DEFAULT_CONCEPT_VERSION"));
+            }
+
+            if (apexModel.getPolicyModel().getSchemas().getSchemasMap().containsKey(key)) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_EXISTS, CONCEPT + key.getID() + ALREADY_EXISTS);
+            }
+
+            apexModel.getPolicyModel().getSchemas().getSchemasMap().put(key, new AxContextSchema(key, schemaFlavour, schemaDefinition));
+
+            if (apexModel.getPolicyModel().getKeyInformation().getKeyInfoMap().containsKey(key)) {
+                return keyInformationFacade.updateKeyInformation(name, version, uuid, description);
+            }
+            else {
+                return keyInformationFacade.createKeyInformation(name, version, uuid, description);
+            }
+        }
+        catch (final Exception e) {
+            return new ApexAPIResult(ApexAPIResult.RESULT.FAILED, e);
+        }
+    }
+
+    /**
+     * Update a context schema.
+     *
+     * @param name name of the context schema
+     * @param version version of the context schema, set to null to update the latest version
+     * @param schemaFlavour a string identifying the flavour of this context schema
+     * @param schemaDefinition a string containing the definition of this context schema
+     * @param uuid context schema UUID, set to null to not update
+     * @param description context schema description, set to null to not update
+     * @return result of the operation
+     */
+    public ApexAPIResult updateContextSchema(final String name, final String version, final String schemaFlavour, final String schemaDefinition,
+            final String uuid, final String description) {
+        try {
+            final AxContextSchema schema = apexModel.getPolicyModel().getSchemas().get(name, version);
+            if (schema == null) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST, CONCEPT + name + ':' + version + DOES_NOT_EXIST);
+            }
+
+            if (schemaFlavour != null) {
+                schema.setSchemaFlavour(schemaFlavour);
+            }
+
+            if (schemaDefinition != null) {
+                schema.setSchema(schemaDefinition);
+            }
+
+            return keyInformationFacade.updateKeyInformation(name, version, uuid, description);
+        }
+        catch (final Exception e) {
+            return new ApexAPIResult(ApexAPIResult.RESULT.FAILED, e);
+        }
+    }
+
+    /**
+     * List context schemas.
+     *
+     * @param name name of the context schema, set to null to list all
+     * @param version starting version of the context schema, set to null to list all versions
+     * @return result of the operation
+     */
+    public ApexAPIResult listContextSchemas(final String name, final String version) {
+        try {
+            final Set<AxContextSchema> schemaSet = apexModel.getPolicyModel().getSchemas().getAll(name, version);
+            if (name != null && schemaSet.isEmpty()) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST, CONCEPT_S + name + ':' + version + DO_ES_NOT_EXIST);
+            }
+
+            final ApexAPIResult result = new ApexAPIResult();
+            for (final AxContextSchema schema : schemaSet) {
+                result.addMessage(new ApexModelStringWriter<AxContextSchema>(false).writeString(schema, AxContextSchema.class, jsonMode));
+            }
+            return result;
+        }
+        catch (final Exception e) {
+            return new ApexAPIResult(ApexAPIResult.RESULT.FAILED, e);
+        }
+    }
+
+    /**
+     * Delete a context schema.
+     *
+     * @param name name of the context schema
+     * @param version version of the context schema, set to null to delete all versions
+     * @return result of the operation
+     */
+    public ApexAPIResult deleteContextSchema(final String name, final String version) {
+        try {
+            if (version != null) {
+                final AxArtifactKey key = new AxArtifactKey(name, version);
+                final AxContextSchema removedSchema = apexModel.getPolicyModel().getSchemas().getSchemasMap().remove(key);
+                if (removedSchema != null) {
+                    return new ApexAPIResult(ApexAPIResult.RESULT.SUCCESS,
+                            new ApexModelStringWriter<AxContextSchema>(false).writeString(removedSchema, AxContextSchema.class, jsonMode));
+                }
+                else {
+                    return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST, CONCEPT + key.getID() + DOES_NOT_EXIST);
+                }
+            }
+
+            final Set<AxContextSchema> schemaSet = apexModel.getPolicyModel().getSchemas().getAll(name, version);
+            if (schemaSet.isEmpty()) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST, CONCEPT_S + name + ':' + version + DO_ES_NOT_EXIST);
+            }
+
+            final ApexAPIResult result = new ApexAPIResult();
+            for (final AxContextSchema schema : schemaSet) {
+                result.addMessage(new ApexModelStringWriter<AxContextSchema>(false).writeString(schema, AxContextSchema.class, jsonMode));
+                apexModel.getPolicyModel().getSchemas().getSchemasMap().remove(schema.getKey());
+                keyInformationFacade.deleteKeyInformation(name, version);
+            }
+            return result;
+        }
+        catch (final Exception e) {
+            return new ApexAPIResult(ApexAPIResult.RESULT.FAILED, e);
+        }
+    }
+
+    /**
+     * Validate context schemas.
+     *
+     * @param name name of the context schema, set to null to list all
+     * @param version starting version of the context schema, set to null to list all versions
+     * @return result of the operation
+     */
+    public ApexAPIResult validateContextSchemas(final String name, final String version) {
+        try {
+            final Set<AxContextSchema> schemaSet = apexModel.getPolicyModel().getSchemas().getAll(name, version);
+            if (schemaSet.isEmpty()) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST, CONCEPT_S + name + ':' + version + DO_ES_NOT_EXIST);
+            }
+
+            final ApexAPIResult result = new ApexAPIResult();
+            for (final AxContextSchema schema : schemaSet) {
+                final AxValidationResult validationResult = schema.validate(new AxValidationResult());
+                result.addMessage(new ApexModelStringWriter<AxArtifactKey>(false).writeString(schema.getKey(), AxArtifactKey.class, jsonMode));
+                result.addMessage(validationResult.toString());
+            }
+            return result;
+        }
+        catch (final Exception e) {
+            return new ApexAPIResult(ApexAPIResult.RESULT.FAILED, e);
+        }
+    }
+}
diff --git a/model/model-api/src/main/java/org/onap/policy/apex/model/modelapi/impl/EventFacade.java b/model/model-api/src/main/java/org/onap/policy/apex/model/modelapi/impl/EventFacade.java
new file mode 100644
index 000000000..095d4f9f4
--- /dev/null
+++ b/model/model-api/src/main/java/org/onap/policy/apex/model/modelapi/impl/EventFacade.java
@@ -0,0 +1,385 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2016-2018 Ericsson. 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 or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * 
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.model.modelapi.impl;
+
+import java.util.Properties;
+import java.util.Set;
+
+import org.onap.policy.apex.model.basicmodel.concepts.AxArtifactKey;
+import org.onap.policy.apex.model.basicmodel.concepts.AxReferenceKey;
+import org.onap.policy.apex.model.basicmodel.concepts.AxValidationResult;
+import org.onap.policy.apex.model.basicmodel.handling.ApexModelStringWriter;
+import org.onap.policy.apex.model.contextmodel.concepts.AxContextSchema;
+import org.onap.policy.apex.model.eventmodel.concepts.AxEvent;
+import org.onap.policy.apex.model.eventmodel.concepts.AxField;
+import org.onap.policy.apex.model.modelapi.ApexAPIResult;
+import org.onap.policy.apex.model.modelapi.ApexModel;
+import org.onap.policy.apex.model.utilities.Assertions;
+
+/**
+ * This class acts as a facade for operations towards a policy model for event operations
+ * operations.
+ *
+ * @author Liam Fallon (liam.fallon@ericsson.com)
+ */
+public class EventFacade {
+    private static final String CONCEPT = "concept ";
+    private static final String CONCEPT_S = "concept(s) ";
+    private static final String DOES_NOT_EXIST = " does not exist";
+    private static final String DO_ES_NOT_EXIST = " do(es) not exist";
+    private static final String ALREADY_EXISTS = " already exists";
+
+    // Apex model we're working towards
+    private final ApexModel apexModel;
+
+    // Properties to use for the model
+    private final Properties apexProperties;
+
+    // Facade classes for working towards the real Apex model
+    private final KeyInformationFacade keyInformationFacade;
+
+    // JSON output on list/delete if set
+    private final boolean jsonMode;
+
+    /**
+     * Constructor to create an event facade for the Model API.
+     *
+     * @param apexModel the apex model
+     * @param apexProperties Properties for the model
+     * @param jsonMode set to true to return JSON strings in list and delete operations, otherwise
+     *        set to false
+     */
+    public EventFacade(final ApexModel apexModel, final Properties apexProperties, final boolean jsonMode) {
+        this.apexModel = apexModel;
+        this.apexProperties = apexProperties;
+        this.jsonMode = jsonMode;
+
+        keyInformationFacade = new KeyInformationFacade(apexModel, apexProperties, jsonMode);
+    }
+
+    /**
+     * Create an event.
+     *
+     * @param name name of the event
+     * @param version version of the event, set to null to use the default version
+     * @param nameSpace of the event, set to null to use the default value
+     * @param source of the event, set to null to use the default value
+     * @param target of the event, set to null to use the default value
+     * @param uuid event UUID, set to null to generate a UUID
+     * @param description event description, set to null to generate a description
+     * @return result of the operation
+     */
+    public ApexAPIResult createEvent(final String name, final String version, final String nameSpace,
+            final String source, final String target, final String uuid, final String description) {
+        try {
+            final AxArtifactKey key = new AxArtifactKey();
+            key.setName(name);
+            if (version != null) {
+                key.setVersion(version);
+            } else {
+                key.setVersion(apexProperties.getProperty("DEFAULT_CONCEPT_VERSION"));
+            }
+
+            if (apexModel.getPolicyModel().getEvents().getEventMap().containsKey(key)) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_EXISTS, CONCEPT + key.getID() + ALREADY_EXISTS);
+            }
+
+            final AxEvent event = new AxEvent(key);
+
+            event.setNameSpace((nameSpace != null ? nameSpace : apexProperties.getProperty("DEFAULT_EVENT_NAMESPACE")));
+            event.setSource((source != null ? source : apexProperties.getProperty("DEFAULT_EVENT_SOURCE")));
+            event.setTarget((target != null ? target : apexProperties.getProperty("DEFAULT_EVENT_TARGET")));
+
+            apexModel.getPolicyModel().getEvents().getEventMap().put(key, event);
+
+            if (apexModel.getPolicyModel().getKeyInformation().getKeyInfoMap().containsKey(key)) {
+                return keyInformationFacade.updateKeyInformation(name, version, uuid, description);
+            } else {
+                return keyInformationFacade.createKeyInformation(name, version, uuid, description);
+            }
+        } catch (final Exception e) {
+            return new ApexAPIResult(ApexAPIResult.RESULT.FAILED, e);
+        }
+    }
+
+    /**
+     * Update an event.
+     *
+     * @param name name of the event
+     * @param version version of the event, set to null to use the latest version
+     * @param nameSpace of the event, set to null to not update
+     * @param source of the event, set to null to not update
+     * @param target of the event, set to null to not update
+     * @param uuid event UUID, set to null to not update
+     * @param description event description, set to null to not update
+     * @return result of the operation
+     */
+    public ApexAPIResult updateEvent(final String name, final String version, final String nameSpace,
+            final String source, final String target, final String uuid, final String description) {
+        try {
+            final AxEvent event = apexModel.getPolicyModel().getEvents().get(name, version);
+            if (event == null) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                        CONCEPT + name + ':' + version + DOES_NOT_EXIST);
+            }
+
+            if (nameSpace != null) {
+                event.setNameSpace(nameSpace);
+            }
+            if (source != null) {
+                event.setSource(source);
+            }
+            if (target != null) {
+                event.setTarget(target);
+            }
+
+            return keyInformationFacade.updateKeyInformation(name, version, uuid, description);
+        } catch (final Exception e) {
+            return new ApexAPIResult(ApexAPIResult.RESULT.FAILED, e);
+        }
+    }
+
+    /**
+     * List events.
+     *
+     * @param name name of the event, set to null to list all
+     * @param version starting version of the event, set to null to list all versions
+     * @return result of the operation
+     */
+    public ApexAPIResult listEvent(final String name, final String version) {
+        try {
+            final Set<AxEvent> eventSet = apexModel.getPolicyModel().getEvents().getAll(name, version);
+            if (name != null && eventSet.isEmpty()) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                        CONCEPT_S + name + ':' + version + DO_ES_NOT_EXIST);
+            }
+
+            final ApexAPIResult result = new ApexAPIResult();
+            for (final AxEvent event : eventSet) {
+                result.addMessage(
+                        new ApexModelStringWriter<AxEvent>(false).writeString(event, AxEvent.class, jsonMode));
+            }
+            return result;
+        } catch (final Exception e) {
+            return new ApexAPIResult(ApexAPIResult.RESULT.FAILED, e);
+        }
+    }
+
+    /**
+     * Delete an event.
+     *
+     * @param name name of the event
+     * @param version version of the event, set to null to delete all versions
+     * @return result of the operation
+     */
+    public ApexAPIResult deleteEvent(final String name, final String version) {
+        try {
+            if (version != null) {
+                final AxArtifactKey key = new AxArtifactKey(name, version);
+                final AxEvent removedEvent = apexModel.getPolicyModel().getEvents().getEventMap().remove(key);
+                if (removedEvent != null) {
+                    return new ApexAPIResult(ApexAPIResult.RESULT.SUCCESS, new ApexModelStringWriter<AxEvent>(false)
+                            .writeString(removedEvent, AxEvent.class, jsonMode));
+                } else {
+                    return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                            CONCEPT + key.getID() + DOES_NOT_EXIST);
+                }
+            }
+
+            final Set<AxEvent> eventSet = apexModel.getPolicyModel().getEvents().getAll(name, version);
+            if (eventSet.isEmpty()) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                        CONCEPT_S + name + ':' + version + DO_ES_NOT_EXIST);
+            }
+
+            final ApexAPIResult result = new ApexAPIResult();
+            for (final AxEvent event : eventSet) {
+                result.addMessage(
+                        new ApexModelStringWriter<AxEvent>(false).writeString(event, AxEvent.class, jsonMode));
+                apexModel.getPolicyModel().getEvents().getEventMap().remove(event.getKey());
+                keyInformationFacade.deleteKeyInformation(name, version);
+            }
+            return result;
+        } catch (final Exception e) {
+            return new ApexAPIResult(ApexAPIResult.RESULT.FAILED, e);
+        }
+    }
+
+    /**
+     * Validate events.
+     *
+     * @param name name of the event, set to null to list all
+     * @param version starting version of the event, set to null to list all versions
+     * @return result of the operation
+     */
+    public ApexAPIResult validateEvent(final String name, final String version) {
+        try {
+            final Set<AxEvent> eventSet = apexModel.getPolicyModel().getEvents().getAll(name, version);
+            if (eventSet.isEmpty()) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                        CONCEPT_S + name + ':' + version + DO_ES_NOT_EXIST);
+            }
+
+            final ApexAPIResult result = new ApexAPIResult();
+            for (final AxEvent event : eventSet) {
+                final AxValidationResult validationResult = event.validate(new AxValidationResult());
+                result.addMessage(new ApexModelStringWriter<AxArtifactKey>(false).writeString(event.getKey(),
+                        AxArtifactKey.class, jsonMode));
+                result.addMessage(validationResult.toString());
+            }
+            return result;
+        } catch (final Exception e) {
+            return new ApexAPIResult(ApexAPIResult.RESULT.FAILED, e);
+        }
+    }
+
+    /**
+     * Create an event parameter.
+     *
+     * @param name name of the event
+     * @param version version of the event, set to null to use the latest version
+     * @param parName of the parameter
+     * @param contextSchemaName name of the parameter context schema
+     * @param contextSchemaVersion version of the parameter context schema, set to null to use the
+     *        latest version
+     * @param optional true if the event parameter is optional, false otherwise
+     * @return result of the operation
+     */
+    public ApexAPIResult createEventPar(final String name, final String version, final String parName,
+            final String contextSchemaName, final String contextSchemaVersion, final boolean optional) {
+        try {
+            Assertions.argumentNotNull(parName, "parName may not be null");
+
+            final AxEvent event = apexModel.getPolicyModel().getEvents().get(name, version);
+            if (event == null) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                        CONCEPT + name + ':' + version + DOES_NOT_EXIST);
+            }
+
+            final AxReferenceKey refKey = new AxReferenceKey(event.getKey(), parName);
+
+            if (event.getParameterMap().containsKey(refKey.getLocalName())) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_EXISTS,
+                        CONCEPT + refKey.getID() + ALREADY_EXISTS);
+            }
+
+            final AxContextSchema schema =
+                    apexModel.getPolicyModel().getSchemas().get(contextSchemaName, contextSchemaVersion);
+            if (schema == null) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                        CONCEPT + contextSchemaName + ':' + contextSchemaVersion + DOES_NOT_EXIST);
+            }
+
+            event.getParameterMap().put(refKey.getLocalName(), new AxField(refKey, schema.getKey(), optional));
+            return new ApexAPIResult();
+        } catch (final Exception e) {
+            return new ApexAPIResult(ApexAPIResult.RESULT.FAILED, e);
+        }
+    }
+
+    /**
+     * List event parameters.
+     *
+     * @param name name of the event
+     * @param version version of the event, set to null to list latest version
+     * @param parName name of the parameter, set to null to list all parameters of the event
+     * @return result of the operation
+     */
+    public ApexAPIResult listEventPar(final String name, final String version, final String parName) {
+        try {
+            final AxEvent event = apexModel.getPolicyModel().getEvents().get(name, version);
+            if (event == null) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                        CONCEPT + name + ':' + version + DOES_NOT_EXIST);
+            }
+
+            if (parName != null) {
+                final AxField eventField = event.getParameterMap().get(parName);
+                if (eventField != null) {
+                    return new ApexAPIResult(ApexAPIResult.RESULT.SUCCESS,
+                            new ApexModelStringWriter<AxField>(false).writeString(eventField, AxField.class, jsonMode));
+                } else {
+                    return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                            CONCEPT + name + ':' + version + ':' + parName + DOES_NOT_EXIST);
+                }
+            } else {
+                if (event.getParameterMap().size() == 0) {
+                    return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                            "no parameters defined on event " + event.getKey().getID());
+                }
+
+                final ApexAPIResult result = new ApexAPIResult();
+                for (final AxField eventPar : event.getParameterMap().values()) {
+                    result.addMessage(
+                            new ApexModelStringWriter<AxField>(false).writeString(eventPar, AxField.class, jsonMode));
+                }
+                return result;
+            }
+        } catch (final Exception e) {
+            return new ApexAPIResult(ApexAPIResult.RESULT.FAILED, e);
+        }
+    }
+
+    /**
+     * Delete an event parameter.
+     *
+     * @param name name of the event
+     * @param version version of the event, set to null to use the latest version
+     * @param parName of the parameter, set to null to delete all parameters
+     * @return result of the operation
+     */
+    public ApexAPIResult deleteEventPar(final String name, final String version, final String parName) {
+        try {
+            final AxEvent event = apexModel.getPolicyModel().getEvents().get(name, version);
+            if (event == null) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                        CONCEPT + name + ':' + version + DOES_NOT_EXIST);
+            }
+
+            final ApexAPIResult result = new ApexAPIResult();
+            if (parName != null) {
+                if (event.getParameterMap().containsKey(parName)) {
+                    result.addMessage(new ApexModelStringWriter<AxField>(false)
+                            .writeString(event.getParameterMap().get(parName), AxField.class, jsonMode));
+                    event.getParameterMap().remove(parName);
+                    return result;
+                } else {
+                    return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                            CONCEPT + name + ':' + version + ':' + parName + DOES_NOT_EXIST);
+                }
+            } else {
+                if (event.getParameterMap().size() == 0) {
+                    return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                            "no parameters defined on event " + event.getKey().getID());
+                }
+
+                for (final AxField eventPar : event.getParameterMap().values()) {
+                    result.addMessage(
+                            new ApexModelStringWriter<AxField>(false).writeString(eventPar, AxField.class, jsonMode));
+                }
+                event.getParameterMap().clear();
+                return result;
+            }
+        } catch (final Exception e) {
+            return new ApexAPIResult(ApexAPIResult.RESULT.FAILED, e);
+        }
+    }
+}
diff --git a/model/model-api/src/main/java/org/onap/policy/apex/model/modelapi/impl/KeyInformationFacade.java b/model/model-api/src/main/java/org/onap/policy/apex/model/modelapi/impl/KeyInformationFacade.java
new file mode 100644
index 000000000..d9b9cef1a
--- /dev/null
+++ b/model/model-api/src/main/java/org/onap/policy/apex/model/modelapi/impl/KeyInformationFacade.java
@@ -0,0 +1,244 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2016-2018 Ericsson. 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 or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * 
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.model.modelapi.impl;
+
+import java.util.Properties;
+import java.util.Set;
+import java.util.UUID;
+
+import org.onap.policy.apex.model.basicmodel.concepts.AxArtifactKey;
+import org.onap.policy.apex.model.basicmodel.concepts.AxKeyInfo;
+import org.onap.policy.apex.model.basicmodel.concepts.AxValidationResult;
+import org.onap.policy.apex.model.basicmodel.handling.ApexModelStringWriter;
+import org.onap.policy.apex.model.modelapi.ApexAPIResult;
+import org.onap.policy.apex.model.modelapi.ApexModel;
+
+/**
+ * This class acts as a facade for operations towards a policy model for key information operations.
+ *
+ * @author Liam Fallon (liam.fallon@ericsson.com)
+ */
+public class KeyInformationFacade {
+    private static final String CONCEPT = "concept ";
+    private static final String CONCEPT_S = "concept(s) ";
+    private static final String DOES_NOT_EXIST = " does not exist";
+    private static final String DO_ES_NOT_EXIST = " do(es) not exist";
+    private static final String ALREADY_EXISTS = " already exists";
+
+    // Apex model we're working towards
+    private final ApexModel apexModel;
+
+    // Properties to use for the model
+    private final Properties apexProperties;
+
+    // JSON output on list/delete if set
+    private final boolean jsonMode;
+
+    /**
+     * Constructor to create a key information facade for the Model API.
+     *
+     * @param apexModel the apex model
+     * @param apexProperties Properties for the model
+     * @param jsonMode set to true to return JSON strings in list and delete operations, otherwise
+     *        set to false
+     */
+    public KeyInformationFacade(final ApexModel apexModel, final Properties apexProperties, final boolean jsonMode) {
+        this.apexModel = apexModel;
+        this.apexProperties = apexProperties;
+        this.jsonMode = jsonMode;
+    }
+
+    /**
+     * Create key information.
+     *
+     * @param name name of the concept for the key information
+     * @param version version of the concept for the key information, set to null to use the default
+     *        version
+     * @param uuid key information UUID, set to null to generate a UUID
+     * @param description key information description, set to null to generate a description
+     * @return result of the operation
+     */
+    public ApexAPIResult createKeyInformation(final String name, final String version, final String uuid,
+            final String description) {
+        try {
+            final AxArtifactKey key = new AxArtifactKey();
+            key.setName(name);
+            if (version != null) {
+                key.setVersion(version);
+            } else {
+                key.setVersion(apexProperties.getProperty("DEFAULT_CONCEPT_VERSION"));
+            }
+
+            if (apexModel.getPolicyModel().getKeyInformation().getKeyInfoMap().containsKey(key)) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_EXISTS, CONCEPT + key.getID() + ALREADY_EXISTS);
+            }
+
+            final AxKeyInfo keyInfo = new AxKeyInfo(key);
+            if (description != null) {
+                keyInfo.setDescription(description);
+            }
+            if (uuid != null) {
+                keyInfo.setUuid(UUID.fromString(uuid));
+            } else {
+                // generate a reproducible UUID
+                keyInfo.setUuid(AxKeyInfo.generateReproducibleUUID(keyInfo.getID() + keyInfo.getDescription()));
+            }
+            apexModel.getPolicyModel().getKeyInformation().getKeyInfoMap().put(key, keyInfo);
+            return new ApexAPIResult();
+        } catch (final Exception e) {
+            return new ApexAPIResult(ApexAPIResult.RESULT.FAILED, e);
+        }
+    }
+
+    /**
+     * Update key information.
+     *
+     * @param name name of the concept for the key information
+     * @param version version of the concept for the key information, set to null to update the
+     *        latest version
+     * @param uuid key information UUID, set to null to not update
+     * @param description key information description, set to null to not update
+     * @return result of the operation
+     */
+    public ApexAPIResult updateKeyInformation(final String name, final String version, final String uuid,
+            final String description) {
+        try {
+            final AxKeyInfo keyInfo = apexModel.getPolicyModel().getKeyInformation().get(name, version);
+            if (keyInfo == null) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                        CONCEPT + name + ":" + version + DOES_NOT_EXIST);
+            }
+
+            if (description != null) {
+                keyInfo.setDescription(description);
+            }
+
+            if (uuid != null) {
+                keyInfo.setUuid(UUID.fromString(uuid));
+            } else {
+                // generate a reproducible UUID
+                keyInfo.setUuid(AxKeyInfo.generateReproducibleUUID(keyInfo.getID() + keyInfo.getDescription()));
+            }
+
+            return new ApexAPIResult();
+        } catch (final Exception e) {
+            return new ApexAPIResult(ApexAPIResult.RESULT.FAILED, e);
+        }
+    }
+
+    /**
+     * List key information.
+     *
+     * @param name name of the concept for the key information, set to null to list all
+     * @param version starting version of the concept for the key information, set to null to list
+     *        all versions
+     * @return result of the operation
+     */
+    public ApexAPIResult listKeyInformation(final String name, final String version) {
+        try {
+            final Set<AxKeyInfo> keyInfoSet = apexModel.getPolicyModel().getKeyInformation().getAll(name, version);
+            if (name != null && keyInfoSet.isEmpty()) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                        CONCEPT_S + name + ':' + version + DO_ES_NOT_EXIST);
+            }
+
+            final ApexAPIResult result = new ApexAPIResult();
+            for (final AxKeyInfo keyInfo : keyInfoSet) {
+                result.addMessage(
+                        new ApexModelStringWriter<AxKeyInfo>(false).writeString(keyInfo, AxKeyInfo.class, jsonMode));
+            }
+            return result;
+        } catch (final Exception e) {
+            return new ApexAPIResult(ApexAPIResult.RESULT.FAILED, e);
+        }
+    }
+
+    /**
+     * Delete key information.
+     *
+     * @param name name of the concept for the key information
+     * @param version version of the concept for the key information, set to null to delete all
+     *        versions
+     * @return result of the operation
+     */
+    public ApexAPIResult deleteKeyInformation(final String name, final String version) {
+        try {
+            if (version != null) {
+                final AxArtifactKey key = new AxArtifactKey(name, version);
+                final AxKeyInfo removedKeyInfo =
+                        apexModel.getPolicyModel().getKeyInformation().getKeyInfoMap().remove(key);
+                if (removedKeyInfo != null) {
+                    return new ApexAPIResult(ApexAPIResult.RESULT.SUCCESS, new ApexModelStringWriter<AxKeyInfo>(false)
+                            .writeString(removedKeyInfo, AxKeyInfo.class, jsonMode));
+                } else {
+                    return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                            CONCEPT + key.getID() + DOES_NOT_EXIST);
+                }
+            }
+
+            final Set<AxKeyInfo> keyInfoSet = apexModel.getPolicyModel().getKeyInformation().getAll(name, version);
+            if (keyInfoSet.isEmpty()) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                        CONCEPT_S + name + ':' + version + DO_ES_NOT_EXIST);
+            }
+
+            final ApexAPIResult result = new ApexAPIResult();
+            for (final AxKeyInfo keyInfo : keyInfoSet) {
+                result.addMessage(
+                        new ApexModelStringWriter<AxKeyInfo>(false).writeString(keyInfo, AxKeyInfo.class, jsonMode));
+                apexModel.getPolicyModel().getKeyInformation().getKeyInfoMap().remove(keyInfo.getKey());
+            }
+            return result;
+        } catch (final Exception e) {
+            return new ApexAPIResult(ApexAPIResult.RESULT.FAILED, e);
+        }
+    }
+
+    /**
+     * Validate key information.
+     *
+     * @param name name of the concept for the key information
+     * @param version version of the concept for the key information, set to null to validate all
+     *        versions
+     * @return result of the operation
+     */
+    public ApexAPIResult validateKeyInformation(final String name, final String version) {
+        try {
+            final Set<AxKeyInfo> keyInfoSet = apexModel.getPolicyModel().getKeyInformation().getAll(name, version);
+            if (keyInfoSet.isEmpty()) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                        CONCEPT_S + name + ':' + version + DO_ES_NOT_EXIST);
+            }
+
+            final ApexAPIResult result = new ApexAPIResult();
+            for (final AxKeyInfo keyInfo : keyInfoSet) {
+                final AxValidationResult validationResult = keyInfo.validate(new AxValidationResult());
+                result.addMessage(new ApexModelStringWriter<AxArtifactKey>(false).writeString(keyInfo.getKey(),
+                        AxArtifactKey.class, jsonMode));
+                result.addMessage(validationResult.toString());
+            }
+            return result;
+        } catch (final Exception e) {
+            return new ApexAPIResult(ApexAPIResult.RESULT.FAILED, e);
+        }
+    }
+
+}
diff --git a/model/model-api/src/main/java/org/onap/policy/apex/model/modelapi/impl/ModelFacade.java b/model/model-api/src/main/java/org/onap/policy/apex/model/modelapi/impl/ModelFacade.java
new file mode 100644
index 000000000..2a6dd3ebf
--- /dev/null
+++ b/model/model-api/src/main/java/org/onap/policy/apex/model/modelapi/impl/ModelFacade.java
@@ -0,0 +1,207 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2016-2018 Ericsson. 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 or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * 
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.model.modelapi.impl;
+
+import java.util.Properties;
+
+import org.onap.policy.apex.model.basicmodel.concepts.AxArtifactKey;
+import org.onap.policy.apex.model.basicmodel.handling.ApexModelStringWriter;
+import org.onap.policy.apex.model.modelapi.ApexAPIResult;
+import org.onap.policy.apex.model.modelapi.ApexModel;
+import org.onap.policy.apex.model.policymodel.concepts.AxPolicyModel;
+import org.onap.policy.apex.model.utilities.Assertions;
+
+/**
+ * This class acts as a facade for operations towards a policy model.
+ *
+ * @author Liam Fallon (liam.fallon@ericsson.com)
+ */
+public class ModelFacade {
+    private static final String CONCEPT = "concept ";
+    private static final String DOES_NOT_EXIST = " does not exist";
+    private static final String ALREADY_CREATED = " already created";
+    private static final String NO_VERSION_SPECIFIED = ", no version specified";
+
+    // Apex model we're working towards
+    private final ApexModel apexModel;
+
+    // Properties to use for the model
+    private final Properties apexProperties;
+
+    // Facade classes for working towards the real Apex model
+    private final KeyInformationFacade keyInformationFacade;
+
+    // JSON output on list/delete if set
+    private final boolean jsonMode;
+
+    /**
+     * Constructor to create a model facade for the Apex model.
+     *
+     * @param apexModel the apex model
+     * @param apexProperties Properties for the model
+     * @param jsonMode set to true to return JSON strings in list and delete operations, otherwise
+     *        set to false
+     */
+    public ModelFacade(final ApexModel apexModel, final Properties apexProperties, final boolean jsonMode) {
+        Assertions.argumentNotNull(apexModel, "apexModel may not be null");
+        Assertions.argumentNotNull(apexProperties, "apexProperties may not be null");
+
+        this.apexModel = apexModel;
+        this.apexProperties = apexProperties;
+        this.jsonMode = jsonMode;
+
+        keyInformationFacade = new KeyInformationFacade(apexModel, apexProperties, jsonMode);
+    }
+
+    /**
+     * Create model.
+     *
+     * @param name name of the model
+     * @param version version of the model, set to null to use the default version
+     * @param uuid model UUID, set to null to generate a UUID
+     * @param description model description, set to null to generate a description
+     * @return result of the operation
+     */
+    public ApexAPIResult createModel(final String name, final String version, final String uuid,
+            final String description) {
+        try {
+            final AxArtifactKey key = new AxArtifactKey();
+            key.setName(name);
+            if (version != null) {
+                key.setVersion(version);
+            } else {
+                final String defaultVersion = apexProperties.getProperty("DEFAULT_CONCEPT_VERSION");
+                if (defaultVersion != null) {
+                    key.setVersion(defaultVersion);
+                } else {
+                    return new ApexAPIResult(ApexAPIResult.RESULT.FAILED, CONCEPT + name + NO_VERSION_SPECIFIED);
+                }
+            }
+
+            if (!apexModel.getPolicyModel().getKey().equals(AxArtifactKey.getNullKey())) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_EXISTS,
+                        CONCEPT + apexModel.getPolicyModel().getKey().getID() + ALREADY_CREATED);
+            }
+
+            apexModel.setPolicyModel(new AxPolicyModel(key));
+
+            ApexAPIResult result;
+
+            result = keyInformationFacade.createKeyInformation(name, version, uuid, description);
+            if (result.getResult().equals(ApexAPIResult.RESULT.SUCCESS)) {
+                apexModel.getPolicyModel().getKeyInformation().generateKeyInfo(apexModel.getPolicyModel());
+            }
+            return result;
+        } catch (final Exception e) {
+            return new ApexAPIResult(ApexAPIResult.RESULT.FAILED, e);
+        }
+    }
+
+    /**
+     * Update model.
+     *
+     * @param name name of the model
+     * @param version version of the model, set to null to update the latest version
+     * @param uuid key information UUID, set to null to not update
+     * @param description policy description, set to null to not update
+     * @return result of the operation
+     */
+    public ApexAPIResult updateModel(final String name, final String version, final String uuid,
+            final String description) {
+        try {
+            final AxArtifactKey key = new AxArtifactKey();
+            key.setName(name);
+            if (version != null) {
+                key.setVersion(version);
+            } else {
+                final String defaultVersion = apexProperties.getProperty("DEFAULT_CONCEPT_VERSION");
+                if (defaultVersion != null) {
+                    key.setVersion(defaultVersion);
+                } else {
+                    return new ApexAPIResult(ApexAPIResult.RESULT.FAILED,
+                            CONCEPT + apexModel.getPolicyModel().getKey().getID() + NO_VERSION_SPECIFIED);
+                }
+            }
+
+            if (apexModel.getPolicyModel().getKey().equals(AxArtifactKey.getNullKey())) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                        CONCEPT + apexModel.getPolicyModel().getKey().getID() + DOES_NOT_EXIST);
+            }
+
+            return keyInformationFacade.updateKeyInformation(name, version, uuid, description);
+        } catch (final Exception e) {
+            return new ApexAPIResult(ApexAPIResult.RESULT.FAILED, e);
+        }
+    }
+
+    /**
+     * Get the key of an Apex model.
+     *
+     * @return the result of the operation
+     */
+    public ApexAPIResult getModelKey() {
+        try {
+            final ApexAPIResult result = new ApexAPIResult();
+            final AxArtifactKey modelkey = apexModel.getPolicyModel().getKey();
+            result.addMessage(new ApexModelStringWriter<AxArtifactKey>(false).writeString(modelkey, AxArtifactKey.class,
+                    jsonMode));
+            return result;
+        } catch (final Exception e) {
+            return new ApexAPIResult(ApexAPIResult.RESULT.FAILED, e);
+        }
+    }
+
+    /**
+     * List an Apex model.
+     *
+     * @return the result of the operation
+     */
+    public ApexAPIResult listModel() {
+        try {
+            final ApexAPIResult result = new ApexAPIResult();
+            result.addMessage(new ApexModelStringWriter<AxPolicyModel>(false).writeString(apexModel.getPolicyModel(),
+                    AxPolicyModel.class, jsonMode));
+            return result;
+        } catch (final Exception e) {
+            return new ApexAPIResult(ApexAPIResult.RESULT.FAILED, e);
+        }
+    }
+
+    /**
+     * Delete an Apex model, clear all the concepts in the model.
+     *
+     * @return the result of the operation
+     */
+    public ApexAPIResult deleteModel() {
+        // @formatter:off
+        apexModel.getPolicyModel().getSchemas()       .getSchemasMap() .clear();
+        apexModel.getPolicyModel().getEvents()        .getEventMap()   .clear();
+        apexModel.getPolicyModel().getAlbums()        .getAlbumsMap()  .clear();
+        apexModel.getPolicyModel().getTasks()         .getTaskMap()    .clear();
+        apexModel.getPolicyModel().getPolicies()      .getPolicyMap()  .clear();
+        apexModel.getPolicyModel().getKeyInformation().getKeyInfoMap() .clear();
+        // @formatter:on
+
+        apexModel.setPolicyModel(new AxPolicyModel());
+
+        return new ApexAPIResult();
+    }
+}
diff --git a/model/model-api/src/main/java/org/onap/policy/apex/model/modelapi/impl/ModelHandlerFacade.java b/model/model-api/src/main/java/org/onap/policy/apex/model/modelapi/impl/ModelHandlerFacade.java
new file mode 100644
index 000000000..89a656a40
--- /dev/null
+++ b/model/model-api/src/main/java/org/onap/policy/apex/model/modelapi/impl/ModelHandlerFacade.java
@@ -0,0 +1,630 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2016-2018 Ericsson. 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 or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * 
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.model.modelapi.impl;
+
+import java.io.ByteArrayInputStream;
+import java.io.File;
+import java.io.IOException;
+import java.io.InputStream;
+import java.net.MalformedURLException;
+import java.net.URL;
+import java.net.URLConnection;
+import java.nio.file.Files;
+import java.util.LinkedHashSet;
+import java.util.List;
+import java.util.Properties;
+import java.util.Set;
+
+import org.onap.policy.apex.model.basicmodel.concepts.ApexException;
+import org.onap.policy.apex.model.basicmodel.concepts.ApexRuntimeException;
+import org.onap.policy.apex.model.basicmodel.concepts.AxArtifactKey;
+import org.onap.policy.apex.model.basicmodel.concepts.AxValidationResult;
+import org.onap.policy.apex.model.basicmodel.dao.ApexDao;
+import org.onap.policy.apex.model.basicmodel.dao.ApexDaoFactory;
+import org.onap.policy.apex.model.basicmodel.dao.DAOParameters;
+import org.onap.policy.apex.model.basicmodel.handling.ApexModelException;
+import org.onap.policy.apex.model.basicmodel.handling.ApexModelFileWriter;
+import org.onap.policy.apex.model.basicmodel.handling.ApexModelReader;
+import org.onap.policy.apex.model.basicmodel.handling.ApexModelStringWriter;
+import org.onap.policy.apex.model.basicmodel.handling.ApexModelWriter;
+import org.onap.policy.apex.model.modelapi.ApexAPIResult;
+import org.onap.policy.apex.model.modelapi.ApexModel;
+import org.onap.policy.apex.model.policymodel.concepts.AxPolicy;
+import org.onap.policy.apex.model.policymodel.concepts.AxPolicyModel;
+import org.onap.policy.apex.model.policymodel.handling.PolicyAnalyser;
+import org.onap.policy.apex.model.policymodel.handling.PolicyAnalysisResult;
+import org.onap.policy.apex.model.policymodel.handling.PolicyModelComparer;
+import org.onap.policy.apex.model.policymodel.handling.PolicyModelMerger;
+import org.onap.policy.apex.model.policymodel.handling.PolicyModelSplitter;
+import org.onap.policy.apex.model.utilities.Assertions;
+import org.onap.policy.apex.model.utilities.ResourceUtils;
+import org.onap.policy.apex.model.utilities.TextFileUtils;
+import org.slf4j.ext.XLogger;
+import org.slf4j.ext.XLoggerFactory;
+
+/**
+ * This class acts as a facade for model handling for the Apex Model API.
+ *
+ * @author Liam Fallon (liam.fallon@ericsson.com)
+ */
+public class ModelHandlerFacade {
+    private static final String FOUND_IN_DATABASE = " found in database";
+    private static final String FILE_NAME_MAY_NOT_BE_NULL = "fileName may not be null";
+    private static final String MODEL = "model ";
+    private static final String ALREADY_LOADED = " already loaded";
+
+    private static final XLogger LOGGER = XLoggerFactory.getXLogger(ModelHandlerFacade.class);
+
+    // Apex model we're working towards
+    private final ApexModel apexModel;
+
+    // JSON output on list/delete if set
+    private final boolean jsonMode;
+
+    /**
+     * This Constructor creates a model handling facade for the given {@link ApexModel}.
+     *
+     * @param apexModel the apex model to manipulate
+     * @param apexProperties properties for the model
+     * @param jsonMode set to true to return JSON strings in list and delete operations, otherwise
+     *        set to false
+     */
+    public ModelHandlerFacade(final ApexModel apexModel, final Properties apexProperties, final boolean jsonMode) {
+        Assertions.argumentNotNull(apexModel, "apexModel may not be null");
+        Assertions.argumentNotNull(apexProperties, "apexProperties may not be null");
+
+        this.apexModel = apexModel;
+        this.jsonMode = jsonMode;
+    }
+
+    /**
+     * Load an Apex model from a string.
+     *
+     * @param modelString the string with the model
+     * @return the result of the operation
+     */
+    public ApexAPIResult loadFromString(final String modelString) {
+        Assertions.argumentNotNull(modelString, "modelString may not be null");
+
+        if (!apexModel.getPolicyModel().getKey().equals(AxArtifactKey.getNullKey())) {
+            return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_EXISTS,
+                    MODEL + apexModel.getPolicyModel().getKey().getID() + ALREADY_LOADED);
+        }
+
+        ApexAPIResult result = new ApexAPIResult();
+        AxPolicyModel newPolicyModel = loadModelFromString(modelString, result);
+        apexModel.setPolicyModel(newPolicyModel != null ? newPolicyModel : new AxPolicyModel());
+
+        return result;
+    }
+
+    /**
+     * Load an Apex model from a file.
+     *
+     * @param fileName the file name of the file with the model
+     * @return the result of the operation
+     */
+    public ApexAPIResult loadFromFile(final String fileName) {
+        Assertions.argumentNotNull(fileName, FILE_NAME_MAY_NOT_BE_NULL);
+
+        if (!apexModel.getPolicyModel().getKey().equals(AxArtifactKey.getNullKey())) {
+            return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_EXISTS,
+                    MODEL + apexModel.getPolicyModel().getKey().getID() + ALREADY_LOADED);
+        }
+
+        ApexAPIResult result = new ApexAPIResult();
+        AxPolicyModel newPolicyModel = loadModelFromFile(fileName, result);
+        apexModel.setPolicyModel(newPolicyModel != null ? newPolicyModel : new AxPolicyModel());
+
+        return result;
+    }
+
+    /**
+     * Save an Apex model to a file.
+     *
+     * @param fileName the file name
+     * @param xmlFlag if true, save the file in XML format, otherwise save the file in the default
+     *        JSON format
+     * @return the result of the operation
+     */
+    public ApexAPIResult saveToFile(final String fileName, final boolean xmlFlag) {
+        Assertions.argumentNotNull(fileName, FILE_NAME_MAY_NOT_BE_NULL);
+
+        ApexModelFileWriter<AxPolicyModel> apexModelFileWriter = new ApexModelFileWriter<>(false);
+
+        try {
+            if (xmlFlag) {
+                apexModelFileWriter.apexModelWriteXMLFile(apexModel.getPolicyModel(), AxPolicyModel.class, fileName);
+            } else {
+                apexModelFileWriter.apexModelWriteJSONFile(apexModel.getPolicyModel(), AxPolicyModel.class, fileName);
+            }
+            return new ApexAPIResult();
+        } catch (ApexException e) {
+            return new ApexAPIResult(ApexAPIResult.RESULT.FAILED, e);
+        }
+    }
+
+    /**
+     * Load an Apex model from a database.
+     *
+     * @param modelName the name of the model to load
+     * @param modelVersion the version of the model to load, loads the policy model from the
+     *        database with this name, if more than one exist, an exception is thrown
+     * @param daoParameters the parameters to use to access the database over JDBC
+     * @return the result of the operation
+     */
+    public ApexAPIResult loadFromDatabase(final String modelName, final String modelVersion,
+            final DAOParameters daoParameters) {
+        Assertions.argumentNotNull(modelName, "modelName may not be null");
+        Assertions.argumentNotNull(daoParameters, "daoParameters may not be null");
+
+        if (!apexModel.getPolicyModel().getKey().equals(AxArtifactKey.getNullKey())) {
+            return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_EXISTS,
+                    MODEL + apexModel.getPolicyModel().getKey().getID() + ALREADY_LOADED);
+        }
+
+        ApexDao apexDao = null;
+        try {
+            apexDao = new ApexDaoFactory().createApexDao(daoParameters);
+            apexDao.init(daoParameters);
+
+            // Single specific model requested
+            if (modelVersion != null) {
+                AxPolicyModel daoPolicyModel =
+                        apexDao.get(AxPolicyModel.class, new AxArtifactKey(modelName, modelVersion));
+
+                if (daoPolicyModel != null) {
+                    apexModel.setPolicyModel(daoPolicyModel);
+                    return new ApexAPIResult();
+                } else {
+                    apexModel.setPolicyModel(new AxPolicyModel());
+                    return new ApexAPIResult(ApexAPIResult.RESULT.FAILED, "no policy model with name " + modelName
+                            + " and version " + modelVersion + FOUND_IN_DATABASE);
+                }
+            }
+            // Fishing expedition
+            else {
+                return searchInDatabase(modelName, apexDao, apexModel);
+            }
+        } catch (ApexException | ApexRuntimeException e) {
+            return new ApexAPIResult(ApexAPIResult.RESULT.FAILED, e);
+        } finally {
+            if (apexDao != null) {
+                apexDao.close();
+            }
+        }
+    }
+
+    /**
+     * Search for an Apex model in the database.
+     *
+     * @param modelName the name of the model to load
+     * @param apexDao the DAO to use to find the model
+     * @param apexModel the APEX model we are loading the found model into
+     * @return the result of the operation
+     */
+    private ApexAPIResult searchInDatabase(String modelName, ApexDao apexDao, ApexModel apexModel) {
+        AxPolicyModel foundPolicyModel = null;
+
+        List<AxPolicyModel> policyModelList = apexDao.getAll(AxPolicyModel.class);
+        for (AxPolicyModel dbPolicyModel : policyModelList) {
+            if (dbPolicyModel.getKey().getName().equals(modelName)) {
+                if (foundPolicyModel == null) {
+                    foundPolicyModel = dbPolicyModel;
+                } else {
+                    return new ApexAPIResult(ApexAPIResult.RESULT.FAILED,
+                            "more than one policy model with name " + modelName + FOUND_IN_DATABASE);
+                }
+            }
+        }
+
+        if (foundPolicyModel != null) {
+            apexModel.setPolicyModel(foundPolicyModel);
+            return new ApexAPIResult();
+        } else {
+            apexModel.setPolicyModel(new AxPolicyModel());
+            return new ApexAPIResult(ApexAPIResult.RESULT.FAILED,
+                    "no policy model with name " + modelName + FOUND_IN_DATABASE);
+        }
+    }
+
+    /**
+     * Save an Apex model to a database.
+     *
+     * @param daoParameters the parameters to use to access the database over JDBC
+     * @return the result of the operation
+     */
+    public ApexAPIResult saveToDatabase(final DAOParameters daoParameters) {
+        ApexDao apexDao = null;
+
+        try {
+            apexDao = new ApexDaoFactory().createApexDao(daoParameters);
+            apexDao.init(daoParameters);
+
+            apexDao.create(apexModel.getPolicyModel());
+            return new ApexAPIResult();
+        } catch (ApexException e) {
+            return new ApexAPIResult(ApexAPIResult.RESULT.FAILED, e);
+        } finally {
+            if (apexDao != null) {
+                apexDao.close();
+            }
+        }
+    }
+
+    /**
+     * Read an APEX model from a location identified by a URL.
+     *
+     * @param urlString the url string
+     * @return the result of the operation
+     */
+    public ApexAPIResult readFromURL(final String urlString) {
+        Assertions.argumentNotNull(urlString, "urlString may not be null");
+
+        if (!apexModel.getPolicyModel().getKey().equals(AxArtifactKey.getNullKey())) {
+            return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_EXISTS,
+                    MODEL + apexModel.getPolicyModel().getKey().getID() + ALREADY_LOADED);
+        }
+
+        URL apexModelURL;
+        try {
+            apexModelURL = new URL(urlString);
+        } catch (MalformedURLException e) {
+            ApexAPIResult result = new ApexAPIResult(ApexAPIResult.RESULT.FAILED);
+            result.addMessage("URL string " + urlString + " is not a valid URL");
+            result.addThrowable(e);
+            return result;
+        }
+
+        try {
+            ApexModelReader<AxPolicyModel> apexModelReader = new ApexModelReader<>(AxPolicyModel.class);
+            apexModelReader.setValidateFlag(false);
+            AxPolicyModel newPolicyModel = apexModelReader.read(apexModelURL.openStream());
+            apexModel.setPolicyModel(newPolicyModel != null ? newPolicyModel : new AxPolicyModel());
+            return new ApexAPIResult();
+        } catch (ApexModelException | IOException e) {
+            apexModel.setPolicyModel(new AxPolicyModel());
+            return new ApexAPIResult(ApexAPIResult.RESULT.FAILED, e);
+        }
+    }
+
+    /**
+     * Write an APEX model to a location identified by a URL.
+     *
+     * @param urlString the URL to read the model from
+     * @param xmlFlag if true, save the file in XML format, otherwise save the file in the default
+     *        JSON format
+     * @return the result of the operation
+     */
+    public ApexAPIResult writeToURL(final String urlString, final boolean xmlFlag) {
+        Assertions.argumentNotNull(urlString, "urlString may not be null");
+
+        URL apexModelURL;
+        try {
+            apexModelURL = new URL(urlString);
+        } catch (MalformedURLException e) {
+            ApexAPIResult result = new ApexAPIResult(ApexAPIResult.RESULT.FAILED);
+            result.addMessage("URL string " + urlString + " is not a valid URL");
+            result.addThrowable(e);
+            return result;
+        }
+
+        try {
+            ApexModelWriter<AxPolicyModel> apexModelWriter = new ApexModelWriter<>(AxPolicyModel.class);
+            apexModelWriter.setValidateFlag(false);
+            apexModelWriter.setJsonOutput(!xmlFlag);
+
+            // Open the URL for output and write the model
+            URLConnection urlConnection = apexModelURL.openConnection();
+            urlConnection.setDoOutput(true);
+
+            apexModelWriter.write(apexModel.getPolicyModel(), urlConnection.getOutputStream());
+            return new ApexAPIResult();
+        } catch (ApexModelException | IOException e) {
+            return new ApexAPIResult(ApexAPIResult.RESULT.FAILED, e);
+        }
+    }
+
+    /**
+     * Analyse an Apex model that shows the concept usage references of a policy model.
+     *
+     * @return the result of the operation
+     */
+    public ApexAPIResult analyse() {
+        PolicyAnalysisResult analysisResult = new PolicyAnalyser().analyse(apexModel.getPolicyModel());
+        return new ApexAPIResult(ApexAPIResult.RESULT.SUCCESS, analysisResult.toString());
+    }
+
+    /**
+     * Validate an Apex model, checking all concepts and references in the model.
+     *
+     * @return the result of the operation
+     */
+    public ApexAPIResult validate() {
+        ApexAPIResult result = new ApexAPIResult();
+        try {
+            AxValidationResult validationResult = apexModel.getPolicyModel().validate(new AxValidationResult());
+
+            if (!validationResult.isValid()) {
+                result.setResult(ApexAPIResult.RESULT.FAILED);
+            }
+            result.addMessage(new ApexModelStringWriter<AxArtifactKey>(false)
+                    .writeString(apexModel.getPolicyModel().getKey(), AxArtifactKey.class, jsonMode));
+            result.addMessage(validationResult.toString());
+            return result;
+        } catch (Exception e) {
+            return new ApexAPIResult(ApexAPIResult.RESULT.FAILED, e);
+        }
+    }
+
+    /**
+     * Compare to Apex models, returning the differences between the models.
+     *
+     * @param otherModelFileName the file name of the other model
+     * @param diffsOnly only returns differences between the model when set
+     * @param keysOnly only returns the keys that are different when set, when not set values are
+     *        also returned
+     * @return the result of the operation
+     */
+    public ApexAPIResult compare(final String otherModelFileName, final boolean diffsOnly, final boolean keysOnly) {
+        ApexAPIResult result = new ApexAPIResult();
+        try {
+            AxPolicyModel otherPolicyModel = loadModelFromFile(otherModelFileName, result);
+            if (!result.getResult().equals(ApexAPIResult.RESULT.SUCCESS)) {
+                return result;
+            }
+
+            PolicyModelComparer policyModelComparer =
+                    new PolicyModelComparer(apexModel.getPolicyModel(), otherPolicyModel);
+            result.addMessage(new ApexModelStringWriter<AxArtifactKey>(false)
+                    .writeString(apexModel.getPolicyModel().getKey(), AxArtifactKey.class, jsonMode));
+            result.addMessage(policyModelComparer.toString());
+
+            return result;
+        } catch (Exception e) {
+            return new ApexAPIResult(ApexAPIResult.RESULT.FAILED, e);
+        }
+    }
+
+    /**
+     * Compare two Apex models, returning the differences between the models.
+     *
+     * @param otherModelString the other model as a string
+     * @param diffsOnly only returns differences between the model when set
+     * @param keysOnly only returns the keys that are different when set, when not set values are
+     *        also returned
+     * @return the result of the operation
+     */
+    public ApexAPIResult compareWithString(final String otherModelString, final boolean diffsOnly,
+            final boolean keysOnly) {
+        ApexAPIResult result = new ApexAPIResult();
+        try {
+            AxPolicyModel otherPolicyModel = loadModelFromString(otherModelString, result);
+            if (!result.getResult().equals(ApexAPIResult.RESULT.SUCCESS)) {
+                return result;
+            }
+
+            PolicyModelComparer policyModelComparer =
+                    new PolicyModelComparer(apexModel.getPolicyModel(), otherPolicyModel);
+            result.addMessage(new ApexModelStringWriter<AxArtifactKey>(false)
+                    .writeString(apexModel.getPolicyModel().getKey(), AxArtifactKey.class, jsonMode));
+            result.addMessage(policyModelComparer.toString());
+
+            return result;
+        } catch (Exception e) {
+            return new ApexAPIResult(ApexAPIResult.RESULT.FAILED, e);
+        }
+    }
+
+    /**
+     * Split out a sub model from an Apex model that contains a given subset of the policies in the
+     * original model.
+     *
+     * @param targetModelName the file name of the target model in which to store the model split
+     *        out from the original model
+     * @param splitOutPolicies the policies form the original model to include in the split out
+     *        model, specified as a comma delimited list of policy names
+     * @return the result of the operation
+     */
+    public ApexAPIResult split(final String targetModelName, final String splitOutPolicies) {
+        Set<AxArtifactKey> requiredPolicySet = new LinkedHashSet<>();
+
+        // Split the policy names on comma
+        String[] policyNames = splitOutPolicies.split(",");
+
+        // Iterate over the policy names
+        for (String policyName : policyNames) {
+            // Split out this specific policy
+            AxPolicy requiredPolicy = apexModel.getPolicyModel().getPolicies().get(policyName);
+
+            if (requiredPolicy != null) {
+                requiredPolicySet.add(requiredPolicy.getKey());
+            } else {
+                return new ApexAPIResult(ApexAPIResult.RESULT.FAILED,
+                        "policy for policy name " + policyName + " not found in model");
+            }
+        }
+
+        try {
+            AxPolicyModel splitPolicyModel =
+                    PolicyModelSplitter.getSubPolicyModel(apexModel.getPolicyModel(), requiredPolicySet, false);
+
+            ApexModelFileWriter<AxPolicyModel> apexModelFileWriter = new ApexModelFileWriter<>(false);
+            apexModelFileWriter.apexModelWriteJSONFile(splitPolicyModel, AxPolicyModel.class, targetModelName);
+            return new ApexAPIResult();
+        } catch (ApexException e) {
+            return new ApexAPIResult(ApexAPIResult.RESULT.FAILED, e);
+        }
+    }
+
+    /**
+     * Split out a sub model from an Apex model that contains a given subset of the policies in the
+     * original model, return the split model in the result as a string.
+     *
+     * @param splitOutPolicies the policies form the original model to include in the split out
+     *        model, specified as a comma delimited list of policy names
+     * @return the result of the operation
+     */
+    public ApexAPIResult split(final String splitOutPolicies) {
+        ApexAPIResult splitResult = new ApexAPIResult();
+        File tempSplitPolicyFile = null;
+        try {
+            tempSplitPolicyFile = File.createTempFile("ApexTempPolicy", null);
+
+            // Split the policy into a temporary file
+            splitResult = split(tempSplitPolicyFile.getCanonicalPath(), splitOutPolicies);
+            if (splitResult.isNOK()) {
+                return splitResult;
+            }
+
+            // Get the policy model into a string
+            String splitPolicyModelString = TextFileUtils.getTextFileAsString(tempSplitPolicyFile.getCanonicalPath());
+
+            // Return the policy model
+            splitResult.addMessage(splitPolicyModelString);
+            return splitResult;
+        } catch (Exception e) {
+            return new ApexAPIResult(ApexAPIResult.RESULT.FAILED,
+                    "split of policy model " + apexModel.getPolicyModel().getID() + " failed", e);
+        } finally {
+            if (tempSplitPolicyFile != null) {
+                try {
+                    Files.delete(tempSplitPolicyFile.toPath());
+                } catch (IOException e) {
+                    LOGGER.debug("delete of temporary file failed", e);
+                }
+            }
+        }
+    }
+
+    /**
+     * Merge two Apex models together.
+     *
+     * @param mergeInModelName the file name of the model to merge into the current model
+     * @param keepOriginal if this flag is set to true, if a concept exists in both models, the
+     *        original model copy of that concept is kept, if the flag is set to false, then the
+     *        copy of the concept from the mergeInModel overwrites the concept in the original model
+     * @return the result of the operation
+     */
+    public ApexAPIResult merge(final String mergeInModelName, final boolean keepOriginal) {
+        ApexAPIResult result = new ApexAPIResult();
+        AxPolicyModel mergeInPolicyModel = loadModelFromFile(mergeInModelName, result);
+        if (!result.getResult().equals(ApexAPIResult.RESULT.SUCCESS)) {
+            return result;
+        }
+
+        try {
+            AxPolicyModel mergedPolicyModel = PolicyModelMerger.getMergedPolicyModel(apexModel.getPolicyModel(),
+                    mergeInPolicyModel, keepOriginal, false);
+            apexModel.setPolicyModel(mergedPolicyModel != null ? mergedPolicyModel : new AxPolicyModel());
+            return new ApexAPIResult();
+        } catch (ApexModelException e) {
+            apexModel.setPolicyModel(new AxPolicyModel());
+            return new ApexAPIResult(ApexAPIResult.RESULT.FAILED, e);
+        }
+    }
+
+    /**
+     * Merge two Apex models together.
+     *
+     * @param otherModelString the model to merge as a string
+     * @param keepOriginal if this flag is set to true, if a concept exists in both models, the
+     *        original model copy of that concept is kept, if the flag is set to false, then the
+     *        copy of the concept from the mergeInModel overwrites the concept in the original model
+     * @return the result of the operation
+     */
+    public ApexAPIResult mergeWithString(final String otherModelString, final boolean keepOriginal) {
+        ApexAPIResult result = new ApexAPIResult();
+        AxPolicyModel mergeInPolicyModel = loadModelFromString(otherModelString, result);
+        if (!result.getResult().equals(ApexAPIResult.RESULT.SUCCESS)) {
+            return result;
+        }
+
+        try {
+            AxPolicyModel mergedPolicyModel = PolicyModelMerger.getMergedPolicyModel(apexModel.getPolicyModel(),
+                    mergeInPolicyModel, keepOriginal, false);
+            apexModel.setPolicyModel(mergedPolicyModel != null ? mergedPolicyModel : new AxPolicyModel());
+            return new ApexAPIResult();
+        } catch (ApexModelException e) {
+            apexModel.setPolicyModel(new AxPolicyModel());
+            return new ApexAPIResult(ApexAPIResult.RESULT.FAILED, e);
+        }
+    }
+
+    /**
+     * Load a policy model from a file.
+     *
+     * @param fileName the name of the file containing the model
+     * @param result the result of the operation
+     * @return the model
+     */
+    private AxPolicyModel loadModelFromFile(final String fileName, final ApexAPIResult result) {
+        Assertions.argumentNotNull(fileName, FILE_NAME_MAY_NOT_BE_NULL);
+
+        AxPolicyModel readModel = null;
+
+        final URL apexModelURL = ResourceUtils.getLocalFile(fileName);
+        if (apexModelURL == null) {
+            result.setResult(ApexAPIResult.RESULT.FAILED);
+            result.addMessage("file " + fileName + " not found");
+            return null;
+        }
+
+        try {
+            ApexModelReader<AxPolicyModel> apexModelReader = new ApexModelReader<>(AxPolicyModel.class);
+            apexModelReader.setValidateFlag(false);
+            readModel = apexModelReader.read(apexModelURL.openStream());
+            result.setResult(ApexAPIResult.RESULT.SUCCESS);
+            return readModel;
+        } catch (Exception e) {
+            result.setResult(ApexAPIResult.RESULT.FAILED);
+            result.addThrowable(e);
+            return null;
+        }
+    }
+
+    /**
+     * Load a policy model from a string.
+     *
+     * @param modelString the string containing the model
+     * @param result the result of the operation
+     * @return the model
+     */
+    private AxPolicyModel loadModelFromString(final String modelString, final ApexAPIResult result) {
+        Assertions.argumentNotNull(modelString, "modelString may not be null");
+
+        AxPolicyModel readModel = null;
+
+        InputStream modelStringStream = new ByteArrayInputStream(modelString.getBytes());
+
+        try {
+            ApexModelReader<AxPolicyModel> apexModelReader = new ApexModelReader<>(AxPolicyModel.class);
+            apexModelReader.setValidateFlag(false);
+            readModel = apexModelReader.read(modelStringStream);
+            result.setResult(ApexAPIResult.RESULT.SUCCESS);
+            return readModel;
+        } catch (Exception e) {
+            result.setResult(ApexAPIResult.RESULT.FAILED);
+            result.addThrowable(e);
+            return null;
+        }
+    }
+}
diff --git a/model/model-api/src/main/java/org/onap/policy/apex/model/modelapi/impl/PolicyFacade.java b/model/model-api/src/main/java/org/onap/policy/apex/model/modelapi/impl/PolicyFacade.java
new file mode 100644
index 000000000..f33627e44
--- /dev/null
+++ b/model/model-api/src/main/java/org/onap/policy/apex/model/modelapi/impl/PolicyFacade.java
@@ -0,0 +1,1383 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2016-2018 Ericsson. 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 or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * 
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.model.modelapi.impl;
+
+import java.util.Map.Entry;
+import java.util.Properties;
+import java.util.Set;
+import java.util.TreeSet;
+
+import org.onap.policy.apex.model.basicmodel.concepts.AxArtifactKey;
+import org.onap.policy.apex.model.basicmodel.concepts.AxKey;
+import org.onap.policy.apex.model.basicmodel.concepts.AxReferenceKey;
+import org.onap.policy.apex.model.basicmodel.concepts.AxValidationResult;
+import org.onap.policy.apex.model.basicmodel.handling.ApexModelStringWriter;
+import org.onap.policy.apex.model.contextmodel.concepts.AxContextAlbum;
+import org.onap.policy.apex.model.eventmodel.concepts.AxEvent;
+import org.onap.policy.apex.model.modelapi.ApexAPIResult;
+import org.onap.policy.apex.model.modelapi.ApexModel;
+import org.onap.policy.apex.model.policymodel.concepts.AxPolicy;
+import org.onap.policy.apex.model.policymodel.concepts.AxState;
+import org.onap.policy.apex.model.policymodel.concepts.AxStateFinalizerLogic;
+import org.onap.policy.apex.model.policymodel.concepts.AxStateOutput;
+import org.onap.policy.apex.model.policymodel.concepts.AxStateTaskOutputType;
+import org.onap.policy.apex.model.policymodel.concepts.AxStateTaskReference;
+import org.onap.policy.apex.model.policymodel.concepts.AxTask;
+import org.onap.policy.apex.model.policymodel.concepts.AxTaskSelectionLogic;
+import org.onap.policy.apex.model.utilities.Assertions;
+
+/**
+ * This class acts as a facade for operations towards a policy model for policy operations.
+ *
+ * @author Liam Fallon (liam.fallon@ericsson.com)
+ */
+public class PolicyFacade {
+    private static final String STATE_NAME_MAY_NOT_BE_NULL = "stateName may not be null";
+    private static final String DOES_NOT_EXIST_ON_STATE = " does not exist on state ";
+    private static final String STATE_FINALIZER_LOGIC = "state finalizer logic ";
+    private static final String DO_ES_NOT_EXIST = " do(es) not exist";
+    private static final String CONCEPT_S = "concept(s) ";
+    private static final String DOES_NOT_EXIST = " does not exist";
+    private static final String CONCEPT = "concept ";
+    private static final String ALREADY_EXISTS = " already exists";
+
+    // Apex model we're working towards
+    private final ApexModel apexModel;
+
+    // Properties to use for the model
+    private final Properties apexProperties;
+
+    // Facade classes for working towards the real Apex model
+    private final KeyInformationFacade keyInformationFacade;
+
+    // JSON output on list/delete if set
+    private final boolean jsonMode;
+
+    /**
+     * Constructor that creates a policy facade for the Apex Model API.
+     *
+     * @param apexModel the apex model
+     * @param apexProperties Properties for the model
+     * @param jsonMode set to true to return JSON strings in list and delete operations, otherwise
+     *        set to false
+     */
+    public PolicyFacade(final ApexModel apexModel, final Properties apexProperties, final boolean jsonMode) {
+        this.apexModel = apexModel;
+        this.apexProperties = apexProperties;
+        this.jsonMode = jsonMode;
+
+        keyInformationFacade = new KeyInformationFacade(apexModel, apexProperties, jsonMode);
+    }
+
+    /**
+     * Create a policy.
+     *
+     * @param name name of the policy
+     * @param version version of the policy, set to null to use the default version
+     * @param template template used to create the policy, set to null to use the default template
+     * @param firstState the first state of the policy
+     * @param uuid policy UUID, set to null to generate a UUID
+     * @param description policy description, set to null to generate a description
+     * @return result of the operation
+     */
+    public ApexAPIResult createPolicy(final String name, final String version, final String template,
+            final String firstState, final String uuid, final String description) {
+        try {
+            final AxArtifactKey key = new AxArtifactKey();
+            key.setName(name);
+            if (version != null) {
+                key.setVersion(version);
+            } else {
+                key.setVersion(apexProperties.getProperty("DEFAULT_CONCEPT_VERSION"));
+            }
+
+            String t = template;
+            if (t == null) {
+                t = apexProperties.getProperty("DEFAULT_POLICY_TEMPLATE");
+            }
+
+            if (apexModel.getPolicyModel().getPolicies().getPolicyMap().containsKey(key)) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_EXISTS, CONCEPT + key.getID() + ALREADY_EXISTS);
+            }
+
+            final AxPolicy policy = new AxPolicy(key);
+            policy.setTemplate(t);
+            policy.setFirstState(firstState);
+
+            apexModel.getPolicyModel().getPolicies().getPolicyMap().put(key, policy);
+
+            if (apexModel.getPolicyModel().getKeyInformation().getKeyInfoMap().containsKey(key)) {
+                return keyInformationFacade.updateKeyInformation(name, version, uuid, description);
+            } else {
+                return keyInformationFacade.createKeyInformation(name, version, uuid, description);
+            }
+        } catch (final Exception e) {
+            return new ApexAPIResult(ApexAPIResult.RESULT.FAILED, e);
+        }
+    }
+
+    /**
+     * Update a policy.
+     *
+     * @param name name of the policy
+     * @param version version of the policy, set to null to use the latest version
+     * @param template template used to create the policy, set to null to not update
+     * @param firstState the first state of the policy
+     * @param uuid policy UUID, set to null to not update
+     * @param description policy description, set to null to not update
+     * @return result of the operation
+     */
+    public ApexAPIResult updatePolicy(final String name, final String version, final String template,
+            final String firstState, final String uuid, final String description) {
+        try {
+            final AxPolicy policy = apexModel.getPolicyModel().getPolicies().get(name, version);
+            if (policy == null) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                        CONCEPT + name + ':' + version + DOES_NOT_EXIST);
+            }
+
+            if (template != null) {
+                policy.setTemplate(template);
+            }
+            if (firstState != null) {
+                policy.setFirstState(firstState);
+            }
+
+            return keyInformationFacade.updateKeyInformation(name, version, uuid, description);
+        } catch (final Exception e) {
+            return new ApexAPIResult(ApexAPIResult.RESULT.FAILED, e);
+        }
+    }
+
+    /**
+     * List policies.
+     *
+     * @param name name of the policy, set to null to list all
+     * @param version starting version of the policy, set to null to list all versions
+     * @return result of the operation
+     */
+    public ApexAPIResult listPolicy(final String name, final String version) {
+        try {
+            final Set<AxPolicy> policySet = apexModel.getPolicyModel().getPolicies().getAll(name, version);
+            if (name != null && policySet.isEmpty()) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                        CONCEPT_S + name + ':' + version + DO_ES_NOT_EXIST);
+            }
+
+            final ApexAPIResult result = new ApexAPIResult();
+            for (final AxPolicy policy : policySet) {
+                result.addMessage(
+                        new ApexModelStringWriter<AxPolicy>(false).writeString(policy, AxPolicy.class, jsonMode));
+            }
+            return result;
+        } catch (final Exception e) {
+            return new ApexAPIResult(ApexAPIResult.RESULT.FAILED, e);
+        }
+    }
+
+    /**
+     * Delete a policy.
+     *
+     * @param name name of the policy
+     * @param version version of the policy, set to null to use the latest version
+     * @return result of the operation
+     */
+    public ApexAPIResult deletePolicy(final String name, final String version) {
+        try {
+            if (version != null) {
+                final AxArtifactKey key = new AxArtifactKey(name, version);
+                final AxPolicy removedPolicy = apexModel.getPolicyModel().getPolicies().getPolicyMap().remove(key);
+                if (removedPolicy != null) {
+                    return new ApexAPIResult(ApexAPIResult.RESULT.SUCCESS, new ApexModelStringWriter<AxPolicy>(false)
+                            .writeString(removedPolicy, AxPolicy.class, jsonMode));
+                } else {
+                    return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                            CONCEPT + key.getID() + DOES_NOT_EXIST);
+                }
+            }
+
+            final Set<AxPolicy> policySet = apexModel.getPolicyModel().getPolicies().getAll(name, version);
+            if (policySet.isEmpty()) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                        CONCEPT_S + name + ':' + version + DO_ES_NOT_EXIST);
+            }
+
+            final ApexAPIResult result = new ApexAPIResult();
+            for (final AxPolicy policy : policySet) {
+                result.addMessage(
+                        new ApexModelStringWriter<AxPolicy>(false).writeString(policy, AxPolicy.class, jsonMode));
+                apexModel.getPolicyModel().getPolicies().getPolicyMap().remove(policy.getKey());
+                keyInformationFacade.deleteKeyInformation(name, version);
+            }
+            return result;
+        } catch (final Exception e) {
+            return new ApexAPIResult(ApexAPIResult.RESULT.FAILED, e);
+        }
+    }
+
+    /**
+     * Validate policies.
+     *
+     * @param name name of the policy, set to null to list all
+     * @param version starting version of the policy, set to null to list all versions
+     * @return result of the operation
+     */
+    public ApexAPIResult validatePolicy(final String name, final String version) {
+        try {
+            final Set<AxPolicy> policySet = apexModel.getPolicyModel().getPolicies().getAll(name, version);
+            if (policySet.isEmpty()) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                        CONCEPT_S + name + ':' + version + DO_ES_NOT_EXIST);
+            }
+
+            final ApexAPIResult result = new ApexAPIResult();
+            for (final AxPolicy policy : policySet) {
+                final AxValidationResult validationResult = policy.validate(new AxValidationResult());
+                result.addMessage(new ApexModelStringWriter<AxArtifactKey>(false).writeString(policy.getKey(),
+                        AxArtifactKey.class, jsonMode));
+                result.addMessage(validationResult.toString());
+            }
+            return result;
+        } catch (final Exception e) {
+            return new ApexAPIResult(ApexAPIResult.RESULT.FAILED, e);
+        }
+    }
+
+    /**
+     * Create a policy state.
+     *
+     * @param name name of the policy
+     * @param version version of the policy, set to null to use the latest version
+     * @param stateName of the state
+     * @param triggerName name of the trigger event for this state
+     * @param triggerVersion version of the trigger event for this state, set to null to use the
+     *        latest version
+     * @param defaultTaskName the default task name
+     * @param defaltTaskVersion the default task version, set to null to use the latest version
+     * @return result of the operation
+     */
+    public ApexAPIResult createPolicyState(final String name, final String version, final String stateName,
+            final String triggerName, final String triggerVersion, final String defaultTaskName,
+            final String defaltTaskVersion) {
+        try {
+            Assertions.argumentNotNull(stateName, STATE_NAME_MAY_NOT_BE_NULL);
+
+            final AxPolicy policy = apexModel.getPolicyModel().getPolicies().get(name, version);
+            if (policy == null) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                        CONCEPT + name + ':' + version + DOES_NOT_EXIST);
+            }
+
+            final AxReferenceKey refKey = new AxReferenceKey(policy.getKey(), stateName);
+
+            if (policy.getStateMap().containsKey(refKey.getLocalName())) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_EXISTS,
+                        CONCEPT + refKey.getID() + ALREADY_EXISTS);
+            }
+
+            final AxEvent triggerEvent = apexModel.getPolicyModel().getEvents().get(triggerName, triggerVersion);
+            if (triggerEvent == null) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                        CONCEPT + triggerName + ':' + triggerVersion + DOES_NOT_EXIST);
+            }
+
+            final AxTask defaultTask = apexModel.getPolicyModel().getTasks().get(defaultTaskName, defaltTaskVersion);
+            if (defaultTask == null) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                        CONCEPT + defaultTaskName + ':' + defaltTaskVersion + DOES_NOT_EXIST);
+            }
+
+            final AxState state = new AxState(refKey);
+            state.setTrigger(triggerEvent.getKey());
+            state.setDefaultTask(defaultTask.getKey());
+
+            policy.getStateMap().put(state.getKey().getLocalName(), state);
+            return new ApexAPIResult();
+        } catch (final Exception e) {
+            return new ApexAPIResult(ApexAPIResult.RESULT.FAILED, e);
+        }
+    }
+
+    /**
+     * Update a policy state.
+     *
+     * @param name name of the policy
+     * @param version version of the policy, set to null to use the latest version
+     * @param stateName of the state
+     * @param triggerName name of the trigger event for this state, set to null to not update
+     * @param triggerVersion version of the trigger event for this state, set to use latest version
+     *        of trigger event
+     * @param defaultTaskName the default task name, set to null to not update
+     * @param defaltTaskVersion the default task version, set to use latest version of default task
+     * @return result of the operation
+     */
+    public ApexAPIResult updatePolicyState(final String name, final String version, final String stateName,
+            final String triggerName, final String triggerVersion, final String defaultTaskName,
+            final String defaltTaskVersion) {
+        try {
+            Assertions.argumentNotNull(stateName, STATE_NAME_MAY_NOT_BE_NULL);
+
+            final AxPolicy policy = apexModel.getPolicyModel().getPolicies().get(name, version);
+            if (policy == null) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                        CONCEPT + name + ':' + version + DOES_NOT_EXIST);
+            }
+
+            final AxState state = policy.getStateMap().get(stateName);
+            if (state == null) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                        CONCEPT + policy.getKey().getID() + ':' + stateName + DOES_NOT_EXIST);
+            }
+
+            if (triggerName != null) {
+                final AxEvent triggerEvent = apexModel.getPolicyModel().getEvents().get(triggerName, triggerVersion);
+                if (triggerEvent == null) {
+                    return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                            CONCEPT + triggerName + ':' + triggerVersion + DOES_NOT_EXIST);
+                }
+                state.setTrigger(triggerEvent.getKey());
+            }
+
+            if (defaultTaskName != null) {
+                final AxTask defaultTask =
+                        apexModel.getPolicyModel().getTasks().get(defaultTaskName, defaltTaskVersion);
+                if (defaultTask == null) {
+                    return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                            CONCEPT + defaultTaskName + ':' + defaltTaskVersion + DOES_NOT_EXIST);
+                }
+                state.setDefaultTask(defaultTask.getKey());
+            }
+
+            return new ApexAPIResult();
+        } catch (final Exception e) {
+            return new ApexAPIResult(ApexAPIResult.RESULT.FAILED, e);
+        }
+    }
+
+    /**
+     * List policy states.
+     *
+     * @param name name of the policy
+     * @param version version of the policy, set to null to use the latest version
+     * @param stateName of the state, set to null to list all states of the policy
+     * @return result of the operation
+     */
+    public ApexAPIResult listPolicyState(final String name, final String version, final String stateName) {
+        try {
+            final AxPolicy policy = apexModel.getPolicyModel().getPolicies().get(name, version);
+            if (policy == null) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                        CONCEPT + name + ':' + version + DOES_NOT_EXIST);
+            }
+
+            if (stateName != null) {
+                final AxState state = policy.getStateMap().get(stateName);
+                if (state != null) {
+                    return new ApexAPIResult(ApexAPIResult.RESULT.SUCCESS,
+                            new ApexModelStringWriter<AxState>(false).writeString(state, AxState.class, jsonMode));
+                } else {
+                    return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                            CONCEPT + name + ':' + version + ':' + state + DOES_NOT_EXIST);
+                }
+            } else {
+                if (policy.getStateMap().size() == 0) {
+                    return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                            "no states defined on policy " + policy.getKey().getID());
+                }
+                final ApexAPIResult result = new ApexAPIResult();
+                for (final AxState state : policy.getStateMap().values()) {
+                    result.addMessage(
+                            new ApexModelStringWriter<AxState>(false).writeString(state, AxState.class, jsonMode));
+                }
+                return result;
+            }
+        } catch (final Exception e) {
+            return new ApexAPIResult(ApexAPIResult.RESULT.FAILED, e);
+        }
+    }
+
+    /**
+     * Delete a policy state.
+     *
+     * @param name name of the policy
+     * @param version version of the policy, set to null to use the latest version
+     * @param stateName of the state, set to null to delete all states
+     * @return result of the operation
+     */
+    public ApexAPIResult deletePolicyState(final String name, final String version, final String stateName) {
+        try {
+            final AxPolicy policy = apexModel.getPolicyModel().getPolicies().get(name, version);
+            if (policy == null) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                        CONCEPT + name + ':' + version + DOES_NOT_EXIST);
+            }
+
+            final ApexAPIResult result = new ApexAPIResult();
+            if (stateName != null) {
+                if (policy.getStateMap().containsKey(stateName)) {
+                    result.addMessage(new ApexModelStringWriter<AxState>(false)
+                            .writeString(policy.getStateMap().get(stateName), AxState.class, jsonMode));
+                    policy.getStateMap().remove(stateName);
+                    return result;
+                } else {
+                    return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                            CONCEPT + name + ':' + version + ':' + stateName + DOES_NOT_EXIST);
+                }
+            } else {
+                if (policy.getStateMap().size() == 0) {
+                    return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                            "no states defined on policy " + policy.getKey().getID());
+                }
+                for (final AxState state : policy.getStateMap().values()) {
+                    result.addMessage(
+                            new ApexModelStringWriter<AxState>(false).writeString(state, AxState.class, jsonMode));
+                }
+                policy.getStateMap().clear();
+                return result;
+            }
+        } catch (final Exception e) {
+            return new ApexAPIResult(ApexAPIResult.RESULT.FAILED, e);
+        }
+    }
+
+    /**
+     * Create task selection logic for a state.
+     *
+     * @param name name of the policy
+     * @param version version of the policy, set to null to use the latest version
+     * @param stateName of the state
+     * @param logicFlavour the task selection logic flavour for the state, set to null to use the
+     *        default task logic flavour
+     * @param logic the source code for the logic of the state
+     * @return result of the operation
+     */
+    public ApexAPIResult createPolicyStateTaskSelectionLogic(final String name, final String version,
+            final String stateName, final String logicFlavour, final String logic) {
+        try {
+            Assertions.argumentNotNull(stateName, STATE_NAME_MAY_NOT_BE_NULL);
+
+            final AxPolicy policy = apexModel.getPolicyModel().getPolicies().get(name, version);
+            if (policy == null) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                        CONCEPT + name + ':' + version + DOES_NOT_EXIST);
+            }
+
+            final AxState state = policy.getStateMap().get(stateName);
+            if (state == null) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                        CONCEPT + policy.getKey().getID() + ':' + stateName + DOES_NOT_EXIST);
+            }
+
+            // There is only one logic item associated with a state so we use a hard coded logic
+            // name
+            final AxReferenceKey refKey = new AxReferenceKey(state.getKey(), "TaskSelectionLogic");
+
+            if (!state.getTaskSelectionLogic().getKey().getLocalName().equals(AxKey.NULL_KEY_NAME)) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_EXISTS,
+                        CONCEPT + refKey.getID() + ALREADY_EXISTS);
+            }
+
+            state.setTaskSelectionLogic(new AxTaskSelectionLogic(refKey, logicFlavour, logic));
+            return new ApexAPIResult();
+        } catch (final Exception e) {
+            return new ApexAPIResult(ApexAPIResult.RESULT.FAILED, e);
+        }
+    }
+
+    /**
+     * Update task selection logic for a state.
+     *
+     * @param name name of the policy
+     * @param version version of the policy, set to null to use the latest version
+     * @param stateName of the state
+     * @param logicFlavour the task selection logic flavour for the state, set to null to not update
+     * @param logic the source code for the logic of the state, set to null to not update
+     * @return result of the operation
+     */
+    public ApexAPIResult updatePolicyStateTaskSelectionLogic(final String name, final String version,
+            final String stateName, final String logicFlavour, final String logic) {
+        try {
+            Assertions.argumentNotNull(stateName, STATE_NAME_MAY_NOT_BE_NULL);
+
+            final AxPolicy policy = apexModel.getPolicyModel().getPolicies().get(name, version);
+            if (policy == null) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                        CONCEPT + name + ':' + version + DOES_NOT_EXIST);
+            }
+
+            final AxState state = policy.getStateMap().get(stateName);
+            if (state == null) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                        CONCEPT + policy.getKey().getID() + ':' + stateName + DOES_NOT_EXIST);
+            }
+
+            if (state.getTaskSelectionLogic().getKey().getLocalName().equals(AxKey.NULL_KEY_NAME)) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                        CONCEPT + state.getTaskSelectionLogic().getKey().getID() + DOES_NOT_EXIST);
+            }
+
+            final AxTaskSelectionLogic taskSelectionLogic = state.getTaskSelectionLogic();
+            if (logicFlavour != null) {
+                taskSelectionLogic.setLogicFlavour(logicFlavour);
+            }
+            if (logic != null) {
+                taskSelectionLogic.setLogic(logic);
+            }
+
+            return new ApexAPIResult();
+        } catch (final Exception e) {
+            return new ApexAPIResult(ApexAPIResult.RESULT.FAILED, e);
+        }
+    }
+
+    /**
+     * List task selection logic for a state.
+     *
+     * @param name name of the policy
+     * @param version version of the policy, set to null to use the latest version
+     * @param stateName of the state
+     * @return result of the operation
+     */
+    public ApexAPIResult listPolicyStateTaskSelectionLogic(final String name, final String version,
+            final String stateName) {
+        try {
+            Assertions.argumentNotNull(stateName, STATE_NAME_MAY_NOT_BE_NULL);
+
+            final AxPolicy policy = apexModel.getPolicyModel().getPolicies().get(name, version);
+            if (policy == null) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                        CONCEPT + name + ':' + version + DOES_NOT_EXIST);
+            }
+
+            final AxState state = policy.getStateMap().get(stateName);
+            if (state == null) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                        CONCEPT + policy.getKey().getID() + ':' + stateName + DOES_NOT_EXIST);
+            }
+
+            return new ApexAPIResult(ApexAPIResult.RESULT.SUCCESS,
+                    new ApexModelStringWriter<AxTaskSelectionLogic>(false).writeString(state.getTaskSelectionLogic(),
+                            AxTaskSelectionLogic.class, jsonMode));
+        } catch (final Exception e) {
+            return new ApexAPIResult(ApexAPIResult.RESULT.FAILED, e);
+        }
+    }
+
+    /**
+     * Delete task selection logic for a state.
+     *
+     * @param name name of the policy
+     * @param version version of the policy, set to null to use the latest version
+     * @param stateName of the state
+     * @return result of the operation
+     */
+    public ApexAPIResult deletePolicyStateTaskSelectionLogic(final String name, final String version,
+            final String stateName) {
+        try {
+            Assertions.argumentNotNull(stateName, STATE_NAME_MAY_NOT_BE_NULL);
+
+            final AxPolicy policy = apexModel.getPolicyModel().getPolicies().get(name, version);
+            if (policy == null) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                        CONCEPT + name + ':' + version + DOES_NOT_EXIST);
+            }
+
+            final AxState state = policy.getStateMap().get(stateName);
+            if (state == null) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                        CONCEPT + policy.getKey().getID() + ':' + stateName + DOES_NOT_EXIST);
+            }
+
+            if (state.getTaskSelectionLogic().getKey().getLocalName().equals(AxKey.NULL_KEY_NAME)) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                        CONCEPT + state.getTaskSelectionLogic().getKey().getID() + DOES_NOT_EXIST);
+            }
+
+            final ApexAPIResult result = new ApexAPIResult();
+            result.addMessage(new ApexModelStringWriter<AxTaskSelectionLogic>(false)
+                    .writeString(state.getTaskSelectionLogic(), AxTaskSelectionLogic.class, jsonMode));
+            state.setTaskSelectionLogic(new AxTaskSelectionLogic());
+            return result;
+        } catch (final Exception e) {
+            return new ApexAPIResult(ApexAPIResult.RESULT.FAILED, e);
+        }
+    }
+
+    /**
+     * Create a policy state output.
+     *
+     * @param name name of the policy
+     * @param version version of the policy, set to null to use the latest version
+     * @param stateName of the state
+     * @param outputName of the state output
+     * @param eventName name of the output event for this state output
+     * @param eventVersion version of the output event for this state output, set to null to use the
+     *        latest version
+     * @param nextState for this state to transition to, set to null if this is the last state that
+     *        the policy transitions to on this branch
+     * @return result of the operation
+     */
+    public ApexAPIResult createPolicyStateOutput(final String name, final String version, final String stateName,
+            final String outputName, final String eventName, final String eventVersion, final String nextState) {
+        try {
+            Assertions.argumentNotNull(stateName, STATE_NAME_MAY_NOT_BE_NULL);
+            Assertions.argumentNotNull(outputName, "outputName may not be null");
+
+            final AxPolicy policy = apexModel.getPolicyModel().getPolicies().get(name, version);
+            if (policy == null) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                        "Policy concept " + name + ':' + version + DOES_NOT_EXIST);
+            }
+
+            final AxState state = policy.getStateMap().get(stateName);
+            if (state == null) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                        "State concept " + policy.getKey().getID() + ':' + stateName + DOES_NOT_EXIST);
+            }
+
+            final AxReferenceKey refKey = new AxReferenceKey(state.getKey(), outputName);
+            if (state.getStateOutputs().containsKey(refKey.getLocalName())) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_EXISTS,
+                        "Output concept " + refKey.getID() + ALREADY_EXISTS);
+            }
+
+            final AxEvent event = apexModel.getPolicyModel().getEvents().get(eventName, eventVersion);
+            if (event == null) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                        "Event concept " + eventName + ':' + eventVersion + DOES_NOT_EXIST);
+            }
+
+            AxReferenceKey nextStateKey = AxReferenceKey.getNullKey();
+            if (nextState != null && !(AxReferenceKey.getNullKey().getLocalName().equals(nextState))) {
+                if (state.getKey().getLocalName().equals(nextState)) {
+                    return new ApexAPIResult(ApexAPIResult.RESULT.FAILED,
+                            "next state " + nextState + " of a state cannot be the state itself");
+                }
+                nextStateKey = new AxReferenceKey(state.getKey().getParentArtifactKey(), nextState);
+
+                if (!policy.getStateMap().containsKey(nextState)) {
+                    return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                            "Next state concept " + nextStateKey.getID() + DOES_NOT_EXIST);
+                }
+            }
+
+            state.getStateOutputs().put(refKey.getLocalName(), new AxStateOutput(refKey, event.getKey(), nextStateKey));
+            return new ApexAPIResult();
+        } catch (final Exception e) {
+            return new ApexAPIResult(ApexAPIResult.RESULT.FAILED, e);
+        }
+    }
+
+    /**
+     * List policy state outputs.
+     *
+     * @param name name of the policy
+     * @param version version of the policy, set to null to use the latest version
+     * @param stateName of the state
+     * @param outputName of the state output, set to null to list all outputs of the state
+     * @return result of the operation
+     */
+    public ApexAPIResult listPolicyStateOutput(final String name, final String version, final String stateName,
+            final String outputName) {
+        try {
+            Assertions.argumentNotNull(stateName, STATE_NAME_MAY_NOT_BE_NULL);
+
+            final AxPolicy policy = apexModel.getPolicyModel().getPolicies().get(name, version);
+            if (policy == null) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                        CONCEPT + name + ':' + version + DOES_NOT_EXIST);
+            }
+
+            final AxState state = policy.getStateMap().get(stateName);
+            if (state == null) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                        CONCEPT + policy.getKey().getID() + ':' + stateName + DOES_NOT_EXIST);
+            }
+
+            if (outputName != null) {
+                final AxStateOutput stateOutput = state.getStateOutputs().get(outputName);
+                if (stateOutput != null) {
+                    return new ApexAPIResult(ApexAPIResult.RESULT.SUCCESS,
+                            new ApexModelStringWriter<AxStateOutput>(false).writeString(stateOutput,
+                                    AxStateOutput.class, jsonMode));
+                } else {
+                    return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                            CONCEPT + state.getKey().getID() + ':' + outputName + DOES_NOT_EXIST);
+                }
+            } else {
+                if (state.getStateOutputs().size() == 0) {
+                    return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                            "no state output concepts exist for state " + state.getKey().getID());
+                }
+
+                final ApexAPIResult result = new ApexAPIResult();
+
+                for (final AxStateOutput stateOutput : state.getStateOutputs().values()) {
+                    result.addMessage(new ApexModelStringWriter<AxStateOutput>(false).writeString(stateOutput,
+                            AxStateOutput.class, jsonMode));
+                }
+                return result;
+            }
+        } catch (final Exception e) {
+            return new ApexAPIResult(ApexAPIResult.RESULT.FAILED, e);
+        }
+    }
+
+    /**
+     * Delete a policy state output.
+     *
+     * @param name name of the policy
+     * @param version version of the policy, set to null to use the latest version
+     * @param stateName of the state
+     * @param outputName of the state output, set to null to delete all state outputs
+     * @return result of the operation
+     */
+    public ApexAPIResult deletePolicyStateOutput(final String name, final String version, final String stateName,
+            final String outputName) {
+        try {
+            Assertions.argumentNotNull(stateName, STATE_NAME_MAY_NOT_BE_NULL);
+
+            final AxPolicy policy = apexModel.getPolicyModel().getPolicies().get(name, version);
+            if (policy == null) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                        CONCEPT + name + ':' + version + DOES_NOT_EXIST);
+            }
+
+            final AxState state = policy.getStateMap().get(stateName);
+            if (state == null) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                        CONCEPT + policy.getKey().getID() + ':' + stateName + DOES_NOT_EXIST);
+            }
+
+            if (outputName != null) {
+                final AxStateOutput stateOutput = state.getStateOutputs().get(outputName);
+                if (stateOutput != null) {
+                    final ApexAPIResult result = new ApexAPIResult(ApexAPIResult.RESULT.SUCCESS,
+                            new ApexModelStringWriter<AxStateOutput>(false).writeString(stateOutput,
+                                    AxStateOutput.class, jsonMode));
+                    state.getStateOutputs().remove(outputName);
+                    return result;
+                } else {
+                    return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                            CONCEPT + state.getKey().getID() + ':' + outputName + DOES_NOT_EXIST);
+                }
+            } else {
+                if (state.getStateOutputs().size() == 0) {
+                    return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                            "no state output concepts exist for state " + state.getKey().getID());
+                }
+
+                final ApexAPIResult result = new ApexAPIResult();
+
+                for (final Entry<String, AxStateOutput> stateOutputEntry : state.getStateOutputs().entrySet()) {
+                    result.addMessage(new ApexModelStringWriter<AxStateOutput>(false)
+                            .writeString(stateOutputEntry.getValue(), AxStateOutput.class, jsonMode));
+                }
+                state.getStateOutputs().clear();
+                return result;
+            }
+        } catch (final Exception e) {
+            return new ApexAPIResult(ApexAPIResult.RESULT.FAILED, e);
+        }
+    }
+
+    /**
+     * Create policy finalizer logic for a state.
+     *
+     * @param name name of the policy
+     * @param version version of the policy, set to null to use the latest version
+     * @param stateName of the state
+     * @param finalizerLogicName name of the state finalizer logic
+     * @param logicFlavour the policy finalizer logic flavour for the state, set to null to use the
+     *        default task logic flavour
+     * @param logic the source code for the logic of the state
+     * @return result of the operation
+     */
+    public ApexAPIResult createPolicyStateFinalizerLogic(final String name, final String version,
+            final String stateName, final String finalizerLogicName, final String logicFlavour, final String logic) {
+        try {
+            Assertions.argumentNotNull(stateName, STATE_NAME_MAY_NOT_BE_NULL);
+            Assertions.argumentNotNull(finalizerLogicName, "finalizerlogicName may not be null");
+
+            final AxPolicy policy = apexModel.getPolicyModel().getPolicies().get(name, version);
+            if (policy == null) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                        CONCEPT + name + ':' + version + DOES_NOT_EXIST);
+            }
+
+            final AxState state = policy.getStateMap().get(stateName);
+            if (state == null) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                        CONCEPT + policy.getKey().getID() + ':' + stateName + DOES_NOT_EXIST);
+            }
+
+            final AxReferenceKey refKey = new AxReferenceKey(state.getKey(), finalizerLogicName);
+
+            if (state.getStateFinalizerLogicMap().containsKey(refKey.getLocalName())) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_EXISTS,
+                        CONCEPT + refKey.getID() + ALREADY_EXISTS);
+            }
+
+            state.getStateFinalizerLogicMap().put(finalizerLogicName,
+                    new AxStateFinalizerLogic(refKey, logicFlavour, logic));
+            return new ApexAPIResult();
+        } catch (final Exception e) {
+            return new ApexAPIResult(ApexAPIResult.RESULT.FAILED, e);
+        }
+    }
+
+    /**
+     * Update policy finalizer logic for a state.
+     *
+     * @param name name of the policy
+     * @param version version of the policy, set to null to use the latest version
+     * @param stateName of the state
+     * @param finalizerLogicName name of the state finalizer logic
+     * @param logicFlavour the policy finalizer logic flavour for the state, set to null to not
+     *        update
+     * @param logic the source code for the logic of the state, set to null to not update
+     * @return result of the operation
+     */
+    public ApexAPIResult updatePolicyStateFinalizerLogic(final String name, final String version,
+            final String stateName, final String finalizerLogicName, final String logicFlavour, final String logic) {
+        try {
+            Assertions.argumentNotNull(stateName, STATE_NAME_MAY_NOT_BE_NULL);
+            Assertions.argumentNotNull(finalizerLogicName, "finalizerLogicName may not be null");
+
+            final AxPolicy policy = apexModel.getPolicyModel().getPolicies().get(name, version);
+            if (policy == null) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                        CONCEPT + name + ':' + version + DOES_NOT_EXIST);
+            }
+
+            final AxState state = policy.getStateMap().get(stateName);
+            if (state == null) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                        CONCEPT + policy.getKey().getID() + ':' + stateName + DOES_NOT_EXIST);
+            }
+
+            final AxReferenceKey refKey = new AxReferenceKey(state.getKey(), finalizerLogicName);
+            final AxStateFinalizerLogic stateFinalizerLogic =
+                    state.getStateFinalizerLogicMap().get(refKey.getKey().getLocalName());
+            if (stateFinalizerLogic == null) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                        STATE_FINALIZER_LOGIC + refKey.getID() + DOES_NOT_EXIST);
+            }
+
+            if (logicFlavour != null) {
+                stateFinalizerLogic.setLogicFlavour(logicFlavour);
+            }
+            if (logic != null) {
+                stateFinalizerLogic.setLogic(logic);
+            }
+
+            return new ApexAPIResult();
+        } catch (final Exception e) {
+            return new ApexAPIResult(ApexAPIResult.RESULT.FAILED, e);
+        }
+    }
+
+    /**
+     * List policy finalizer logic for a state.
+     *
+     * @param name name of the policy
+     * @param version version of the policy, set to null to use the latest version
+     * @param stateName of the state
+     * @param finalizerLogicName name of the state finalizer logic
+     * @return result of the operation
+     */
+    public ApexAPIResult listPolicyStateFinalizerLogic(final String name, final String version, final String stateName,
+            final String finalizerLogicName) {
+        try {
+            Assertions.argumentNotNull(stateName, STATE_NAME_MAY_NOT_BE_NULL);
+
+            final AxPolicy policy = apexModel.getPolicyModel().getPolicies().get(name, version);
+            if (policy == null) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                        CONCEPT + name + ':' + version + DOES_NOT_EXIST);
+            }
+
+            final AxState state = policy.getStateMap().get(stateName);
+            if (state == null) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                        CONCEPT + policy.getKey().getID() + ':' + stateName + DOES_NOT_EXIST);
+            }
+
+            if (finalizerLogicName != null) {
+                final AxReferenceKey refKey = new AxReferenceKey(state.getKey(), finalizerLogicName);
+                final AxStateFinalizerLogic stateFinalizerLogic =
+                        state.getStateFinalizerLogicMap().get(refKey.getKey().getLocalName());
+                if (stateFinalizerLogic == null) {
+                    return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                            STATE_FINALIZER_LOGIC + refKey.getID() + DOES_NOT_EXIST);
+                }
+
+                return new ApexAPIResult(ApexAPIResult.RESULT.SUCCESS,
+                        new ApexModelStringWriter<AxStateFinalizerLogic>(false).writeString(stateFinalizerLogic,
+                                AxStateFinalizerLogic.class, jsonMode));
+            } else {
+                if (state.getStateFinalizerLogicMap().size() == 0) {
+                    return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                            "no state finalizer logic defined on state " + state.getKey().getID());
+                }
+                final ApexAPIResult result = new ApexAPIResult();
+                for (final AxStateFinalizerLogic stateFinalizerLogic : state.getStateFinalizerLogicMap().values()) {
+                    result.addMessage(new ApexModelStringWriter<AxStateFinalizerLogic>(false)
+                            .writeString(stateFinalizerLogic, AxStateFinalizerLogic.class, jsonMode));
+                }
+                return result;
+            }
+        } catch (final Exception e) {
+            return new ApexAPIResult(ApexAPIResult.RESULT.FAILED, e);
+        }
+    }
+
+    /**
+     * Delete policy finalizer logic for a state.
+     *
+     * @param name name of the policy
+     * @param version version of the policy, set to null to use the latest version
+     * @param stateName of the state
+     * @param finalizerLogicName name of the state finalizer logic
+     * @return result of the operation
+     */
+    public ApexAPIResult deletePolicyStateFinalizerLogic(final String name, final String version,
+            final String stateName, final String finalizerLogicName) {
+        try {
+            Assertions.argumentNotNull(stateName, STATE_NAME_MAY_NOT_BE_NULL);
+
+            final AxPolicy policy = apexModel.getPolicyModel().getPolicies().get(name, version);
+            if (policy == null) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                        CONCEPT + name + ':' + version + DOES_NOT_EXIST);
+            }
+
+            final AxState state = policy.getStateMap().get(stateName);
+            if (state == null) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                        CONCEPT + policy.getKey().getID() + ':' + stateName + DOES_NOT_EXIST);
+            }
+
+            if (finalizerLogicName != null) {
+                final AxReferenceKey refKey = new AxReferenceKey(state.getKey(), finalizerLogicName);
+                final AxStateFinalizerLogic stateFinalizerLogic =
+                        state.getStateFinalizerLogicMap().get(refKey.getKey().getLocalName());
+                if (stateFinalizerLogic == null) {
+                    return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                            STATE_FINALIZER_LOGIC + refKey.getID() + DOES_NOT_EXIST);
+                }
+
+                final ApexAPIResult result = new ApexAPIResult();
+                result.addMessage(new ApexModelStringWriter<AxStateFinalizerLogic>(false)
+                        .writeString(stateFinalizerLogic, AxStateFinalizerLogic.class, jsonMode));
+                state.getStateFinalizerLogicMap().remove(refKey.getLocalName());
+                return result;
+            } else {
+                if (state.getStateFinalizerLogicMap().size() == 0) {
+                    return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                            "no state finalizer logic defined on state " + state.getKey().getID());
+                }
+
+                final ApexAPIResult result = new ApexAPIResult();
+                for (final AxStateFinalizerLogic stateFinalizerLogic : state.getStateFinalizerLogicMap().values()) {
+                    result.addMessage(new ApexModelStringWriter<AxStateFinalizerLogic>(false)
+                            .writeString(stateFinalizerLogic, AxStateFinalizerLogic.class, jsonMode));
+                }
+                state.getStateFinalizerLogicMap().clear();
+                return result;
+            }
+        } catch (final Exception e) {
+            return new ApexAPIResult(ApexAPIResult.RESULT.FAILED, e);
+        }
+    }
+
+    /**
+     * Create a policy state task reference.
+     *
+     * @param name name of the policy
+     * @param version version of the policy, set to null to use the latest version
+     * @param stateName of the state
+     * @param taskLocalName the task local name
+     * @param taskName name of the task
+     * @param taskVersion version of the task, set to null to use the latest version
+     * @param outputType Type of output for the task, must be DIRECT for direct output to a state
+     *        output or LOGIC for output to state finalizer logic
+     * @param outputName the name of the state output or state state finalizer logic to handle the
+     *        task output
+     * @return result of the operation
+     */
+    // CHECKSTYLE:OFF: checkstyle:parameterNumber
+    public ApexAPIResult createPolicyStateTaskRef(final String name, final String version, final String stateName,
+            final String taskLocalName, final String taskName, final String taskVersion, final String outputType,
+            final String outputName) {
+        try {
+            Assertions.argumentNotNull(stateName, STATE_NAME_MAY_NOT_BE_NULL);
+            Assertions.argumentNotNull(outputName, "outputName may not be null");
+
+            final AxPolicy policy = apexModel.getPolicyModel().getPolicies().get(name, version);
+            if (policy == null) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                        CONCEPT + name + ':' + version + DOES_NOT_EXIST);
+            }
+
+            final AxState state = policy.getStateMap().get(stateName);
+            if (state == null) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                        CONCEPT + policy.getKey().getID() + ':' + stateName + DOES_NOT_EXIST);
+            }
+
+            final AxTask task = apexModel.getPolicyModel().getTasks().get(taskName, taskVersion);
+            if (task == null) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                        CONCEPT + taskName + ':' + taskVersion + DOES_NOT_EXIST);
+            }
+
+            if (state.getTaskReferences().containsKey(task.getKey())) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_EXISTS, "task " + task.getKey().getID()
+                        + " already has reference with output " + state.getTaskReferences().get(task.getKey()));
+            }
+
+            AxReferenceKey refKey;
+            if (taskLocalName == null) {
+                refKey = new AxReferenceKey(state.getKey(), state.getKey().getParentKeyName());
+            } else {
+                refKey = new AxReferenceKey(state.getKey(), taskLocalName);
+            }
+
+            // The reference to the output we're using here
+            final AxReferenceKey outputRefKey = new AxReferenceKey(state.getKey(), outputName);
+
+            final AxStateTaskOutputType stateTaskOutputType = AxStateTaskOutputType.valueOf(outputType);
+            if (stateTaskOutputType.equals(AxStateTaskOutputType.DIRECT)) {
+                if (!state.getStateOutputs().containsKey(outputRefKey.getLocalName())) {
+                    return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                            "state output concept " + outputRefKey.getID() + DOES_NOT_EXIST);
+                }
+            } else if (stateTaskOutputType.equals(AxStateTaskOutputType.LOGIC)) {
+                if (!state.getStateFinalizerLogicMap().containsKey(outputRefKey.getLocalName())) {
+                    return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                            "state finalizer logic concept " + outputRefKey.getID() + DOES_NOT_EXIST);
+                }
+            } else {
+                return new ApexAPIResult(ApexAPIResult.RESULT.FAILED, "output type " + outputType + " invalid");
+            }
+
+            state.getTaskReferences().put(task.getKey(),
+                    new AxStateTaskReference(refKey, stateTaskOutputType, outputRefKey));
+            return new ApexAPIResult();
+        } catch (final Exception e) {
+            return new ApexAPIResult(ApexAPIResult.RESULT.FAILED, e);
+        }
+    }
+    // CHECKSTYLE:ON: checkstyle:parameterNumber
+
+    /**
+     * List policy state task references.
+     *
+     * @param name name of the policy
+     * @param version version of the policy, set to null to use the latest version
+     * @param stateName of the state
+     * @param taskName name of the task, set to null to list all task references
+     * @param taskVersion version of the task, set to null to use the latest version
+     * @return result of the operation
+     */
+    public ApexAPIResult listPolicyStateTaskRef(final String name, final String version, final String stateName,
+            final String taskName, final String taskVersion) {
+        try {
+            Assertions.argumentNotNull(stateName, STATE_NAME_MAY_NOT_BE_NULL);
+
+            final AxPolicy policy = apexModel.getPolicyModel().getPolicies().get(name, version);
+            if (policy == null) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                        CONCEPT + name + ':' + version + DOES_NOT_EXIST);
+            }
+
+            final AxState state = policy.getStateMap().get(stateName);
+            if (state == null) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                        CONCEPT + policy.getKey().getID() + ':' + stateName + DOES_NOT_EXIST);
+            }
+
+            final ApexAPIResult result = new ApexAPIResult();
+            boolean found = false;
+            for (final Entry<AxArtifactKey, AxStateTaskReference> taskReferenceEntry : state.getTaskReferences()
+                    .entrySet()) {
+                if (taskName == null) {
+                    result.addMessage(new ApexModelStringWriter<AxArtifactKey>(false)
+                            .writeString(taskReferenceEntry.getKey(), AxArtifactKey.class, jsonMode));
+                    result.addMessage(new ApexModelStringWriter<AxStateTaskReference>(false)
+                            .writeString(taskReferenceEntry.getValue(), AxStateTaskReference.class, jsonMode));
+                    found = true;
+                    continue;
+                }
+                if (!taskReferenceEntry.getKey().getName().equals(taskName)) {
+                    continue;
+                }
+
+                if (taskVersion != null && !taskReferenceEntry.getKey().getVersion().equals(taskVersion)) {
+                    continue;
+                }
+
+                found = true;
+                result.addMessage(new ApexModelStringWriter<AxArtifactKey>(false)
+                        .writeString(taskReferenceEntry.getKey(), AxArtifactKey.class, jsonMode));
+                result.addMessage(new ApexModelStringWriter<AxStateTaskReference>(false)
+                        .writeString(taskReferenceEntry.getValue(), AxStateTaskReference.class, jsonMode));
+            }
+            if (found) {
+                return result;
+            } else {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                        "no task references found for state " + state.getKey().getID());
+            }
+        } catch (final Exception e) {
+            return new ApexAPIResult(ApexAPIResult.RESULT.FAILED, e);
+        }
+    }
+
+    /**
+     * Delete a policy state task reference.
+     *
+     * @param name name of the policy
+     * @param version version of the policy, set to null to use the latest version
+     * @param stateName of the state
+     * @param taskName name of the task, set to null to delete all task references
+     * @param taskVersion version of the task, set to null to use the latest version
+     * @return result of the operation
+     */
+    public ApexAPIResult deletePolicyStateTaskRef(final String name, final String version, final String stateName,
+            final String taskName, final String taskVersion) {
+        try {
+            Assertions.argumentNotNull(stateName, STATE_NAME_MAY_NOT_BE_NULL);
+
+            final AxPolicy policy = apexModel.getPolicyModel().getPolicies().get(name, version);
+            if (policy == null) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                        CONCEPT + name + ':' + version + DOES_NOT_EXIST);
+            }
+
+            final AxState state = policy.getStateMap().get(stateName);
+            if (state == null) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                        CONCEPT + policy.getKey().getID() + ':' + stateName + DOES_NOT_EXIST);
+            }
+
+            final Set<AxArtifactKey> deleteSet = new TreeSet<>();
+
+            for (final AxArtifactKey taskReferenceKey : state.getTaskReferences().keySet()) {
+                if (taskName == null) {
+                    deleteSet.add(taskReferenceKey);
+                    continue;
+                }
+                if (!taskReferenceKey.getName().equals(taskName)) {
+                    continue;
+                }
+
+                if (taskVersion != null && !taskReferenceKey.getVersion().equals(taskVersion)) {
+                    continue;
+                }
+                deleteSet.add(taskReferenceKey);
+            }
+            if (deleteSet.isEmpty()) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                        CONCEPT + taskName + ':' + taskVersion + DOES_NOT_EXIST_ON_STATE + state.getKey().getID());
+            }
+
+            final ApexAPIResult result = new ApexAPIResult();
+            for (final AxArtifactKey keyToDelete : deleteSet) {
+                state.getTaskReferences().remove(keyToDelete);
+                result.addMessage(new ApexModelStringWriter<AxArtifactKey>(false).writeString(keyToDelete,
+                        AxArtifactKey.class, jsonMode));
+            }
+            return result;
+        } catch (final Exception e) {
+            return new ApexAPIResult(ApexAPIResult.RESULT.FAILED, e);
+        }
+    }
+
+    /**
+     * Create a policy state context album reference.
+     *
+     * @param name name of the policy
+     * @param version version of the policy, set to null to use the latest version
+     * @param stateName of the state
+     * @param contextAlbumName name of the context album for the context album reference
+     * @param contextAlbumVersion version of the context album for the context album reference, set
+     *        to null to use the latest version
+     * @return result of the operation
+     */
+    public ApexAPIResult createPolicyStateContextRef(final String name, final String version, final String stateName,
+            final String contextAlbumName, final String contextAlbumVersion) {
+        try {
+            Assertions.argumentNotNull(stateName, STATE_NAME_MAY_NOT_BE_NULL);
+
+            final AxPolicy policy = apexModel.getPolicyModel().getPolicies().get(name, version);
+            if (policy == null) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                        CONCEPT + name + ':' + version + DOES_NOT_EXIST);
+            }
+
+            final AxState state = policy.getStateMap().get(stateName);
+            if (state == null) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                        CONCEPT + policy.getKey().getID() + ':' + stateName + DOES_NOT_EXIST);
+            }
+
+            final AxContextAlbum contextAlbum =
+                    apexModel.getPolicyModel().getAlbums().get(contextAlbumName, contextAlbumVersion);
+            if (contextAlbum == null) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                        CONCEPT + contextAlbumName + ':' + contextAlbumVersion + DOES_NOT_EXIST);
+            }
+
+            if (state.getContextAlbumReferences().contains(contextAlbum.getKey())) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_EXISTS, "concept album reference for concept "
+                        + contextAlbum.getKey().getID() + " already exists in state");
+            }
+
+            state.getContextAlbumReferences().add(contextAlbum.getKey());
+            return new ApexAPIResult();
+        } catch (final Exception e) {
+            return new ApexAPIResult(ApexAPIResult.RESULT.FAILED, e);
+        }
+    }
+
+    /**
+     * List policy state context album references.
+     *
+     * @param name name of the policy
+     * @param version version of the policy, set to null to use the latest version
+     * @param stateName of the state
+     * @param contextAlbumName name of the context album for the context album reference, set to
+     *        null to list all task context album references
+     * @param contextAlbumVersion version of the context album for the context album reference, set
+     *        to null to use the latest version
+     * @return result of the operation
+     */
+    public ApexAPIResult listPolicyStateContextRef(final String name, final String version, final String stateName,
+            final String contextAlbumName, final String contextAlbumVersion) {
+        try {
+            Assertions.argumentNotNull(stateName, STATE_NAME_MAY_NOT_BE_NULL);
+
+            final AxPolicy policy = apexModel.getPolicyModel().getPolicies().get(name, version);
+            if (policy == null) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                        CONCEPT + name + ':' + version + DOES_NOT_EXIST);
+            }
+
+            final AxState state = policy.getStateMap().get(stateName);
+            if (state == null) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                        CONCEPT + policy.getKey().getID() + ':' + stateName + DOES_NOT_EXIST);
+            }
+
+            final ApexAPIResult result = new ApexAPIResult();
+            boolean found = false;
+            for (final AxArtifactKey albumKey : state.getContextAlbumReferences()) {
+                if (contextAlbumName == null) {
+                    result.addMessage(new ApexModelStringWriter<AxArtifactKey>(false).writeString(albumKey,
+                            AxArtifactKey.class, jsonMode));
+                    found = true;
+                    continue;
+                }
+
+                if (!albumKey.getName().equals(contextAlbumName)) {
+                    continue;
+                }
+
+                if (contextAlbumVersion == null || albumKey.getVersion().equals(contextAlbumVersion)) {
+                    result.addMessage(new ApexModelStringWriter<AxArtifactKey>(false).writeString(albumKey,
+                            AxArtifactKey.class, jsonMode));
+                    found = true;
+                }
+            }
+            if (!found) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST, CONCEPT + contextAlbumName + ':'
+                        + contextAlbumVersion + DOES_NOT_EXIST_ON_STATE + state.getKey().getID());
+            }
+            return result;
+        } catch (final Exception e) {
+            return new ApexAPIResult(ApexAPIResult.RESULT.FAILED, e);
+        }
+    }
+
+    /**
+     * Delete a policy state context album reference.
+     *
+     * @param name name of the policy
+     * @param version version of the policy, set to null to use the default version
+     * @param stateName of the state
+     * @param contextAlbumName name of the context album for the context album reference, set to
+     *        null to delete all task context album references
+     * @param contextAlbumVersion version of the context album for the context album reference, set
+     *        to null to use the latest version
+     * @return result of the operation
+     */
+    public ApexAPIResult deletePolicyStateContextRef(final String name, final String version, final String stateName,
+            final String contextAlbumName, final String contextAlbumVersion) {
+        try {
+            Assertions.argumentNotNull(stateName, STATE_NAME_MAY_NOT_BE_NULL);
+
+            final AxPolicy policy = apexModel.getPolicyModel().getPolicies().get(name, version);
+            if (policy == null) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                        CONCEPT + name + ':' + version + DOES_NOT_EXIST);
+            }
+
+            final AxState state = policy.getStateMap().get(stateName);
+            if (state == null) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                        CONCEPT + policy.getKey().getID() + ':' + stateName + DOES_NOT_EXIST);
+            }
+
+            final Set<AxArtifactKey> deleteSet = new TreeSet<>();
+
+            for (final AxArtifactKey albumKey : state.getContextAlbumReferences()) {
+                if (contextAlbumName == null) {
+                    deleteSet.add(albumKey);
+                    continue;
+                }
+
+                if (!albumKey.getName().equals(contextAlbumName)) {
+                    continue;
+                }
+
+                if (contextAlbumVersion == null || albumKey.getVersion().equals(contextAlbumVersion)) {
+                    deleteSet.add(albumKey);
+                }
+            }
+            if (deleteSet.isEmpty()) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST, CONCEPT + contextAlbumName + ':'
+                        + contextAlbumVersion + DOES_NOT_EXIST_ON_STATE + state.getKey().getID());
+            }
+
+            final ApexAPIResult result = new ApexAPIResult();
+            for (final AxArtifactKey keyToDelete : deleteSet) {
+                state.getContextAlbumReferences().remove(keyToDelete);
+                result.addMessage(new ApexModelStringWriter<AxArtifactKey>(false).writeString(keyToDelete,
+                        AxArtifactKey.class, jsonMode));
+            }
+            return result;
+        } catch (final Exception e) {
+            return new ApexAPIResult(ApexAPIResult.RESULT.FAILED, e);
+        }
+    }
+}
diff --git a/model/model-api/src/main/java/org/onap/policy/apex/model/modelapi/impl/TaskFacade.java b/model/model-api/src/main/java/org/onap/policy/apex/model/modelapi/impl/TaskFacade.java
new file mode 100644
index 000000000..923814daf
--- /dev/null
+++ b/model/model-api/src/main/java/org/onap/policy/apex/model/modelapi/impl/TaskFacade.java
@@ -0,0 +1,893 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2016-2018 Ericsson. 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 or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * 
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.apex.model.modelapi.impl;
+
+import java.util.Properties;
+import java.util.Set;
+import java.util.TreeSet;
+
+import org.onap.policy.apex.model.basicmodel.concepts.AxArtifactKey;
+import org.onap.policy.apex.model.basicmodel.concepts.AxKey;
+import org.onap.policy.apex.model.basicmodel.concepts.AxReferenceKey;
+import org.onap.policy.apex.model.basicmodel.concepts.AxValidationResult;
+import org.onap.policy.apex.model.basicmodel.handling.ApexModelStringWriter;
+import org.onap.policy.apex.model.contextmodel.concepts.AxContextAlbum;
+import org.onap.policy.apex.model.contextmodel.concepts.AxContextSchema;
+import org.onap.policy.apex.model.eventmodel.concepts.AxInputField;
+import org.onap.policy.apex.model.eventmodel.concepts.AxOutputField;
+import org.onap.policy.apex.model.modelapi.ApexAPIResult;
+import org.onap.policy.apex.model.modelapi.ApexModel;
+import org.onap.policy.apex.model.policymodel.concepts.AxTask;
+import org.onap.policy.apex.model.policymodel.concepts.AxTaskLogic;
+import org.onap.policy.apex.model.policymodel.concepts.AxTaskParameter;
+import org.onap.policy.apex.model.utilities.Assertions;
+
+/**
+ * This class acts as a facade for operations towards a policy model for task operations.
+ *
+ * @author Liam Fallon (liam.fallon@ericsson.com)
+ */
+public class TaskFacade {
+    private static final String CONCEPT = "concept ";
+    private static final String CONCEPT_S = "concept(s) ";
+    private static final String DOES_NOT_EXIST = " does not exist";
+    private static final String DO_ES_NOT_EXIST = " do(es) not exist";
+    private static final String ALREADY_EXISTS = " already exists";
+
+    // Apex model we're working towards
+    private final ApexModel apexModel;
+
+    // Properties to use for the model
+    private final Properties apexProperties;
+
+    // Facade classes for working towards the real Apex model
+    private final KeyInformationFacade keyInformationFacade;
+
+    // JSON output on list/delete if set
+    private final boolean jsonMode;
+
+    /**
+     * Constructor that creates a task facade for the Apex Model API.
+     *
+     * @param apexModel the apex model
+     * @param apexProperties Properties for the model
+     * @param jsonMode set to true to return JSON strings in list and delete operations, otherwise
+     *        set to false
+     */
+    public TaskFacade(final ApexModel apexModel, final Properties apexProperties, final boolean jsonMode) {
+        this.apexModel = apexModel;
+        this.apexProperties = apexProperties;
+        this.jsonMode = jsonMode;
+
+        keyInformationFacade = new KeyInformationFacade(apexModel, apexProperties, jsonMode);
+    }
+
+    /**
+     * Create a task.
+     *
+     * @param name name of the task
+     * @param version version of the task, set to null to use the default version
+     * @param uuid task UUID, set to null to generate a UUID
+     * @param description task description, set to null to generate a description
+     * @return result of the operation
+     */
+    public ApexAPIResult createTask(final String name, final String version, final String uuid,
+            final String description) {
+        try {
+            final AxArtifactKey key = new AxArtifactKey();
+            key.setName(name);
+            if (version != null) {
+                key.setVersion(version);
+            } else {
+                key.setVersion(apexProperties.getProperty("DEFAULT_CONCEPT_VERSION"));
+            }
+
+            if (apexModel.getPolicyModel().getTasks().getTaskMap().containsKey(key)) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_EXISTS, CONCEPT + key.getID() + ALREADY_EXISTS);
+            }
+
+            apexModel.getPolicyModel().getTasks().getTaskMap().put(key, new AxTask(key));
+
+            if (apexModel.getPolicyModel().getKeyInformation().getKeyInfoMap().containsKey(key)) {
+                return keyInformationFacade.updateKeyInformation(name, version, uuid, description);
+            } else {
+                return keyInformationFacade.createKeyInformation(name, version, uuid, description);
+            }
+        } catch (final Exception e) {
+            return new ApexAPIResult(ApexAPIResult.RESULT.FAILED, e);
+        }
+    }
+
+    /**
+     * Update a task.
+     *
+     * @param name name of the task
+     * @param version version of the task, set to null to use the latest version
+     * @param uuid task UUID, set to null to not update
+     * @param description task description, set to null to not update
+     * @return result of the operation
+     */
+    public ApexAPIResult updateTask(final String name, final String version, final String uuid,
+            final String description) {
+        try {
+            final AxTask task = apexModel.getPolicyModel().getTasks().get(name, version);
+            if (task == null) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                        CONCEPT + name + ':' + version + DOES_NOT_EXIST);
+            }
+
+            return keyInformationFacade.updateKeyInformation(name, version, uuid, description);
+        } catch (final Exception e) {
+            return new ApexAPIResult(ApexAPIResult.RESULT.FAILED, e);
+        }
+    }
+
+    /**
+     * List tasks.
+     *
+     * @param name name of the task, set to null to list all
+     * @param version starting version of the task, set to null to list all versions
+     * @return result of the operation
+     */
+    public ApexAPIResult listTask(final String name, final String version) {
+        try {
+            final Set<AxTask> taskSet = apexModel.getPolicyModel().getTasks().getAll(name, version);
+            if (name != null && taskSet.isEmpty()) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                        CONCEPT_S + name + ':' + version + DO_ES_NOT_EXIST);
+            }
+
+            final ApexAPIResult result = new ApexAPIResult();
+            for (final AxTask task : taskSet) {
+                result.addMessage(new ApexModelStringWriter<AxTask>(false).writeString(task, AxTask.class, jsonMode));
+            }
+            return result;
+        } catch (final Exception e) {
+            return new ApexAPIResult(ApexAPIResult.RESULT.FAILED, e);
+        }
+    }
+
+    /**
+     * Delete a task.
+     *
+     * @param name name of the task
+     * @param version version of the task, set to null to use the latest version
+     * @return result of the operation
+     */
+    public ApexAPIResult deleteTask(final String name, final String version) {
+        try {
+            if (version != null) {
+                final AxArtifactKey key = new AxArtifactKey(name, version);
+                final AxTask removedTask = apexModel.getPolicyModel().getTasks().getTaskMap().remove(key);
+                if (removedTask != null) {
+                    return new ApexAPIResult(ApexAPIResult.RESULT.SUCCESS,
+                            new ApexModelStringWriter<AxTask>(false).writeString(removedTask, AxTask.class, jsonMode));
+                } else {
+                    return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                            CONCEPT + key.getID() + DOES_NOT_EXIST);
+                }
+            }
+
+            final Set<AxTask> taskSet = apexModel.getPolicyModel().getTasks().getAll(name, version);
+            if (taskSet.isEmpty()) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                        CONCEPT_S + name + ':' + version + DO_ES_NOT_EXIST);
+            }
+
+            final ApexAPIResult result = new ApexAPIResult();
+            for (final AxTask task : taskSet) {
+                result.addMessage(new ApexModelStringWriter<AxTask>(false).writeString(task, AxTask.class, jsonMode));
+                apexModel.getPolicyModel().getTasks().getTaskMap().remove(task.getKey());
+                keyInformationFacade.deleteKeyInformation(name, version);
+            }
+            return result;
+        } catch (final Exception e) {
+            return new ApexAPIResult(ApexAPIResult.RESULT.FAILED, e);
+        }
+    }
+
+    /**
+     * Validate tasks.
+     *
+     * @param name name of the task, set to null to list all
+     * @param version starting version of the task, set to null to list all versions
+     * @return result of the operation
+     */
+    public ApexAPIResult validateTask(final String name, final String version) {
+        try {
+            final Set<AxTask> taskSet = apexModel.getPolicyModel().getTasks().getAll(name, version);
+            if (taskSet.isEmpty()) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                        CONCEPT_S + name + ':' + version + DO_ES_NOT_EXIST);
+            }
+
+            final ApexAPIResult result = new ApexAPIResult();
+            for (final AxTask task : taskSet) {
+                final AxValidationResult validationResult = task.validate(new AxValidationResult());
+                result.addMessage(new ApexModelStringWriter<AxArtifactKey>(false).writeString(task.getKey(),
+                        AxArtifactKey.class, jsonMode));
+                result.addMessage(validationResult.toString());
+            }
+            return result;
+        } catch (final Exception e) {
+            return new ApexAPIResult(ApexAPIResult.RESULT.FAILED, e);
+        }
+    }
+
+    /**
+     * Create logic for a task.
+     *
+     * @param name name of the task
+     * @param version version of the task, set to null to use the latest version
+     * @param logicFlavour the task logic flavour for the task, set to null to use the default task
+     *        logic flavour
+     * @param logic the source code for the logic of the task
+     * @return result of the operation
+     */
+    public ApexAPIResult createTaskLogic(final String name, final String version, final String logicFlavour,
+            final String logic) {
+        try {
+            final AxTask task = apexModel.getPolicyModel().getTasks().get(name, version);
+            if (task == null) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                        CONCEPT + name + ':' + version + DOES_NOT_EXIST);
+            }
+
+            // There is only one logic item associated with a task so we use a hard coded logic name
+            final AxReferenceKey refKey = new AxReferenceKey(task.getKey(), "TaskLogic");
+
+            if (!task.getTaskLogic().getKey().getLocalName().equals(AxKey.NULL_KEY_NAME)) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_EXISTS,
+                        CONCEPT + refKey.getID() + ALREADY_EXISTS);
+            }
+
+            task.setTaskLogic(new AxTaskLogic(refKey, logicFlavour, logic));
+            return new ApexAPIResult();
+        } catch (final Exception e) {
+            return new ApexAPIResult(ApexAPIResult.RESULT.FAILED, e);
+        }
+    }
+
+    /**
+     * Update logic for a task.
+     *
+     * @param name name of the task
+     * @param version version of the task, set to null to use the latest version
+     * @param logicFlavour the task logic flavour for the task, set to null to not update
+     * @param logic the source code for the logic of the task, set to null to not update
+     * @return result of the operation
+     */
+    public ApexAPIResult updateTaskLogic(final String name, final String version, final String logicFlavour,
+            final String logic) {
+        try {
+            final AxTask task = apexModel.getPolicyModel().getTasks().get(name, version);
+            if (task == null) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                        CONCEPT + name + ':' + version + DOES_NOT_EXIST);
+            }
+
+            if (task.getTaskLogic().getKey().getLocalName().equals(AxKey.NULL_KEY_NAME)) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                        CONCEPT + task.getTaskLogic().getKey().getID() + DOES_NOT_EXIST);
+            }
+
+            final AxTaskLogic taskLogic = task.getTaskLogic();
+            if (logicFlavour != null) {
+                taskLogic.setLogicFlavour(logicFlavour);
+            }
+            if (logic != null) {
+                taskLogic.setLogic(logic);
+            }
+
+            return new ApexAPIResult();
+        } catch (final Exception e) {
+            return new ApexAPIResult(ApexAPIResult.RESULT.FAILED, e);
+        }
+    }
+
+    /**
+     * List task logic.
+     *
+     * @param name name of the task
+     * @param version version of the task, set to null to list the latest version
+     * @return result of the operation
+     */
+    public ApexAPIResult listTaskLogic(final String name, final String version) {
+        try {
+            final AxTask task = apexModel.getPolicyModel().getTasks().get(name, version);
+            if (task == null) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                        CONCEPT + name + ':' + version + DOES_NOT_EXIST);
+            }
+
+            return new ApexAPIResult(ApexAPIResult.RESULT.SUCCESS, new ApexModelStringWriter<AxTaskLogic>(false)
+                    .writeString(task.getTaskLogic(), AxTaskLogic.class, jsonMode));
+        } catch (final Exception e) {
+            return new ApexAPIResult(ApexAPIResult.RESULT.FAILED, e);
+        }
+    }
+
+    /**
+     * Delete logic for a task.
+     *
+     * @param name name of the task
+     * @param version version of the task, set to null to use the latest version
+     * @return result of the operation
+     */
+    public ApexAPIResult deleteTaskLogic(final String name, final String version) {
+        try {
+            final AxTask task = apexModel.getPolicyModel().getTasks().get(name, version);
+            if (task == null) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                        CONCEPT + name + ':' + version + DOES_NOT_EXIST);
+            }
+
+            if (task.getTaskLogic().getKey().getLocalName().equals(AxKey.NULL_KEY_NAME)) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                        CONCEPT + task.getTaskLogic().getKey().getID() + DOES_NOT_EXIST);
+            }
+
+            final ApexAPIResult result = new ApexAPIResult();
+            result.addMessage(new ApexModelStringWriter<AxTaskLogic>(false).writeString(task.getTaskLogic(),
+                    AxTaskLogic.class, jsonMode));
+            task.setTaskLogic(new AxTaskLogic());
+            return result;
+        } catch (final Exception e) {
+            return new ApexAPIResult(ApexAPIResult.RESULT.FAILED, e);
+        }
+    }
+
+    /**
+     * Create a task input field.
+     *
+     * @param name name of the task
+     * @param version version of the task, set to null to use the latest version
+     * @param fieldName of the input field
+     * @param contextSchemaName name of the input field context schema
+     * @param contextSchemaVersion version of the input field context schema, set to null to use the
+     *        latest version
+     * @param optional true if the task field is optional, false otherwise
+     * @return result of the operation
+     */
+    public ApexAPIResult createTaskInputField(final String name, final String version, final String fieldName,
+            final String contextSchemaName, final String contextSchemaVersion, final boolean optional) {
+        try {
+            Assertions.argumentNotNull(fieldName, "fieldName may not be null");
+
+            final AxTask task = apexModel.getPolicyModel().getTasks().get(name, version);
+            if (task == null) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                        CONCEPT + name + ':' + version + DOES_NOT_EXIST);
+            }
+
+            final AxReferenceKey refKey =
+                    new AxReferenceKey(task.getKey().getName(), task.getKey().getVersion(), "inputFields", fieldName);
+
+            if (task.getInputFields().containsKey(refKey.getLocalName())) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_EXISTS,
+                        CONCEPT + refKey.getID() + ALREADY_EXISTS);
+            }
+
+            final AxContextSchema schema =
+                    apexModel.getPolicyModel().getSchemas().get(contextSchemaName, contextSchemaVersion);
+            if (schema == null) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                        CONCEPT + contextSchemaName + ':' + contextSchemaVersion + DOES_NOT_EXIST);
+            }
+
+            task.getInputFields().put(refKey.getLocalName(), new AxInputField(refKey, schema.getKey(), optional));
+            return new ApexAPIResult();
+        } catch (final Exception e) {
+            return new ApexAPIResult(ApexAPIResult.RESULT.FAILED, e);
+        }
+    }
+
+    /**
+     * List task input fields.
+     *
+     * @param name name of the task
+     * @param version version of the task, set to null to use the latest version
+     * @param fieldName field name of the input field, set to null to list all input fields of the
+     *        task
+     * @return result of the operation
+     */
+    public ApexAPIResult listTaskInputField(final String name, final String version, final String fieldName) {
+        try {
+            final AxTask task = apexModel.getPolicyModel().getTasks().get(name, version);
+            if (task == null) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                        CONCEPT + name + ':' + version + DOES_NOT_EXIST);
+            }
+
+            if (fieldName != null) {
+                final AxInputField inputField = task.getInputFields().get(fieldName);
+                if (inputField != null) {
+                    return new ApexAPIResult(ApexAPIResult.RESULT.SUCCESS,
+                            new ApexModelStringWriter<AxInputField>(false).writeString(inputField, AxInputField.class,
+                                    jsonMode));
+                } else {
+                    return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                            CONCEPT + name + ':' + version + ':' + inputField + DOES_NOT_EXIST);
+                }
+            } else {
+                if (task.getInputFields().size() == 0) {
+                    return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                            "no input fields defined on task " + task.getKey().getID());
+                }
+
+                final ApexAPIResult result = new ApexAPIResult();
+                for (final AxInputField field : task.getInputFields().values()) {
+                    result.addMessage(new ApexModelStringWriter<AxInputField>(false).writeString(field,
+                            AxInputField.class, jsonMode));
+                }
+                return result;
+            }
+        } catch (final Exception e) {
+            return new ApexAPIResult(ApexAPIResult.RESULT.FAILED, e);
+        }
+
+    }
+
+    /**
+     * Delete a task input field.
+     *
+     * @param name name of the task
+     * @param version version of the task, set to null to use the latest version
+     * @param fieldName of the input field, set to null to delete all input fields
+     * @return result of the operation
+     */
+    public ApexAPIResult deleteTaskInputField(final String name, final String version, final String fieldName) {
+        try {
+            final AxTask task = apexModel.getPolicyModel().getTasks().get(name, version);
+            if (task == null) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                        CONCEPT + name + ':' + version + DOES_NOT_EXIST);
+            }
+
+            final ApexAPIResult result = new ApexAPIResult();
+            if (fieldName != null) {
+                if (task.getInputFields().containsKey(fieldName)) {
+                    result.addMessage(new ApexModelStringWriter<AxInputField>(false)
+                            .writeString(task.getInputFields().get(fieldName), AxInputField.class, jsonMode));
+                    task.getInputFields().remove(fieldName);
+                    return result;
+                } else {
+                    return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                            CONCEPT + name + ':' + version + ':' + fieldName + DOES_NOT_EXIST);
+                }
+            } else {
+                if (task.getInputFields().size() == 0) {
+                    return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                            "no input fields defined on task " + task.getKey().getID());
+                }
+
+                for (final AxInputField field : task.getInputFields().values()) {
+                    result.addMessage(new ApexModelStringWriter<AxInputField>(false).writeString(field,
+                            AxInputField.class, jsonMode));
+                }
+                task.getInputFields().clear();
+                return result;
+            }
+        } catch (final Exception e) {
+            return new ApexAPIResult(ApexAPIResult.RESULT.FAILED, e);
+        }
+
+    }
+
+    /**
+     * Create a task output field.
+     *
+     * @param name name of the task
+     * @param version version of the task, set to null to use the latest version
+     * @param fieldName of the output field
+     * @param contextSchemaName name of the output field context schema
+     * @param contextSchemaVersion version of the output field context schema, set to null to use
+     *        the latest version
+     * @param optional true if the task field is optional, false otherwise
+     * @return result of the operation
+     */
+    public ApexAPIResult createTaskOutputField(final String name, final String version, final String fieldName,
+            final String contextSchemaName, final String contextSchemaVersion, final boolean optional) {
+        try {
+            Assertions.argumentNotNull(fieldName, "fieldName may not be null");
+
+            final AxTask task = apexModel.getPolicyModel().getTasks().get(name, version);
+            if (task == null) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                        CONCEPT + name + ':' + version + DOES_NOT_EXIST);
+            }
+
+            final AxReferenceKey refKey =
+                    new AxReferenceKey(task.getKey().getName(), task.getKey().getVersion(), "outputFields", fieldName);
+
+            if (task.getOutputFields().containsKey(refKey.getLocalName())) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_EXISTS,
+                        CONCEPT + refKey.getID() + ALREADY_EXISTS);
+            }
+
+            final AxContextSchema schema =
+                    apexModel.getPolicyModel().getSchemas().get(contextSchemaName, contextSchemaVersion);
+            if (schema == null) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                        CONCEPT + contextSchemaName + ':' + contextSchemaVersion + DOES_NOT_EXIST);
+            }
+
+            task.getOutputFields().put(refKey.getLocalName(), new AxOutputField(refKey, schema.getKey(), optional));
+            return new ApexAPIResult();
+        } catch (final Exception e) {
+            return new ApexAPIResult(ApexAPIResult.RESULT.FAILED, e);
+        }
+    }
+
+    /**
+     * List task output fields.
+     *
+     * @param name name of the task
+     * @param version version of the task, set to null to use the latest version
+     * @param fieldName field name of the output field, set to null to list all output fields of the
+     *        task
+     * @return result of the operation
+     */
+    public ApexAPIResult listTaskOutputField(final String name, final String version, final String fieldName) {
+        try {
+            final AxTask task = apexModel.getPolicyModel().getTasks().get(name, version);
+            if (task == null) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                        CONCEPT + name + ':' + version + DOES_NOT_EXIST);
+            }
+
+            if (fieldName != null) {
+                final AxOutputField outputField = task.getOutputFields().get(fieldName);
+                if (outputField != null) {
+                    return new ApexAPIResult(ApexAPIResult.RESULT.SUCCESS,
+                            new ApexModelStringWriter<AxOutputField>(false).writeString(outputField,
+                                    AxOutputField.class, jsonMode));
+                } else {
+                    return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                            CONCEPT + name + ':' + version + ':' + outputField + DOES_NOT_EXIST);
+                }
+            } else {
+                if (task.getOutputFields().size() == 0) {
+                    return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                            "no output fields defined on task " + task.getKey().getID());
+                }
+
+                final ApexAPIResult result = new ApexAPIResult();
+                for (final AxOutputField field : task.getOutputFields().values()) {
+                    result.addMessage(new ApexModelStringWriter<AxOutputField>(false).writeString(field,
+                            AxOutputField.class, jsonMode));
+                }
+                return result;
+            }
+        } catch (final Exception e) {
+            return new ApexAPIResult(ApexAPIResult.RESULT.FAILED, e);
+        }
+    }
+
+    /**
+     * Delete a task output field.
+     *
+     * @param name name of the task
+     * @param version version of the task, set to null to use the latest version
+     * @param fieldName of the output field, set to null to delete all output fields
+     * @return result of the operation
+     */
+    public ApexAPIResult deleteTaskOutputField(final String name, final String version, final String fieldName) {
+        try {
+            final AxTask task = apexModel.getPolicyModel().getTasks().get(name, version);
+            if (task == null) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                        CONCEPT + name + ':' + version + DOES_NOT_EXIST);
+            }
+
+            final ApexAPIResult result = new ApexAPIResult();
+            if (fieldName != null) {
+                if (task.getOutputFields().containsKey(fieldName)) {
+                    result.addMessage(new ApexModelStringWriter<AxOutputField>(false)
+                            .writeString(task.getOutputFields().get(fieldName), AxOutputField.class, jsonMode));
+                    task.getOutputFields().remove(fieldName);
+                    return result;
+                } else {
+                    return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                            CONCEPT + name + ':' + version + ':' + fieldName + DOES_NOT_EXIST);
+                }
+            } else {
+                if (task.getOutputFields().size() == 0) {
+                    return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                            "no output fields defined on task " + task.getKey().getID());
+                }
+
+                for (final AxOutputField field : task.getOutputFields().values()) {
+                    result.addMessage(new ApexModelStringWriter<AxOutputField>(false).writeString(field,
+                            AxOutputField.class, jsonMode));
+                }
+                task.getOutputFields().clear();
+                return result;
+            }
+        } catch (final Exception e) {
+            return new ApexAPIResult(ApexAPIResult.RESULT.FAILED, e);
+        }
+    }
+
+    /**
+     * Create a task parameter.
+     *
+     * @param name name of the task
+     * @param version version of the task, set to null to use the latest version
+     * @param parName of the parameter
+     * @param defaultValue of the parameter
+     * @return result of the operation
+     */
+    public ApexAPIResult createTaskParameter(final String name, final String version, final String parName,
+            final String defaultValue) {
+        try {
+            Assertions.argumentNotNull(parName, "parName may not be null");
+
+            final AxTask task = apexModel.getPolicyModel().getTasks().get(name, version);
+            if (task == null) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                        CONCEPT + name + ':' + version + DOES_NOT_EXIST);
+            }
+
+            final AxReferenceKey refKey = new AxReferenceKey(task.getKey(), parName);
+
+            if (task.getTaskParameters().containsKey(refKey.getLocalName())) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_EXISTS,
+                        CONCEPT + refKey.getID() + ALREADY_EXISTS);
+            }
+
+            task.getTaskParameters().put(refKey.getLocalName(), new AxTaskParameter(refKey, defaultValue));
+            return new ApexAPIResult();
+        } catch (final Exception e) {
+            return new ApexAPIResult(ApexAPIResult.RESULT.FAILED, e);
+        }
+    }
+
+    /**
+     * List task parameters.
+     *
+     * @param name name of the task
+     * @param version version of the task, set to null to use the latest version
+     * @param parName name of the parameter, set to null to list all parameters of the task
+     * @return result of the operation
+     */
+    public ApexAPIResult listTaskParameter(final String name, final String version, final String parName) {
+        try {
+            final AxTask task = apexModel.getPolicyModel().getTasks().get(name, version);
+            if (task == null) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                        CONCEPT + name + ':' + version + DOES_NOT_EXIST);
+            }
+
+            if (parName != null) {
+                final AxTaskParameter taskParameter = task.getTaskParameters().get(parName);
+                if (taskParameter != null) {
+                    return new ApexAPIResult(ApexAPIResult.RESULT.SUCCESS,
+                            new ApexModelStringWriter<AxTaskParameter>(false).writeString(taskParameter,
+                                    AxTaskParameter.class, jsonMode));
+                } else {
+                    return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                            CONCEPT + name + ':' + version + ':' + taskParameter + DOES_NOT_EXIST);
+                }
+            } else {
+                if (task.getTaskParameters().size() == 0) {
+                    return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                            "no task parameters defined on task " + task.getKey().getID());
+                }
+
+                final ApexAPIResult result = new ApexAPIResult();
+                for (final AxTaskParameter parameter : task.getTaskParameters().values()) {
+                    result.addMessage(new ApexModelStringWriter<AxTaskParameter>(false).writeString(parameter,
+                            AxTaskParameter.class, jsonMode));
+                }
+                return result;
+            }
+        } catch (final Exception e) {
+            return new ApexAPIResult(ApexAPIResult.RESULT.FAILED, e);
+        }
+    }
+
+    /**
+     * Delete a task parameter.
+     *
+     * @param name name of the task
+     * @param version version of the task, set to null to use the latest version
+     * @param parName of the parameter, set to null to delete all task parameters
+     * @return result of the operation
+     */
+    public ApexAPIResult deleteTaskParameter(final String name, final String version, final String parName) {
+        try {
+            final AxTask task = apexModel.getPolicyModel().getTasks().get(name, version);
+            if (task == null) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                        CONCEPT + name + ':' + version + DOES_NOT_EXIST);
+            }
+
+            final ApexAPIResult result = new ApexAPIResult();
+            if (parName != null) {
+                if (task.getTaskParameters().containsKey(parName)) {
+                    result.addMessage(new ApexModelStringWriter<AxTaskParameter>(false)
+                            .writeString(task.getTaskParameters().get(parName), AxTaskParameter.class, jsonMode));
+                    task.getTaskParameters().remove(parName);
+                    return result;
+                } else {
+                    return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                            CONCEPT + name + ':' + version + ':' + parName + DOES_NOT_EXIST);
+                }
+            } else {
+                if (task.getTaskParameters().size() == 0) {
+                    return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                            "no task parameters defined on task " + task.getKey().getID());
+                }
+
+                for (final AxTaskParameter parameter : task.getTaskParameters().values()) {
+                    result.addMessage(new ApexModelStringWriter<AxTaskParameter>(false).writeString(parameter,
+                            AxTaskParameter.class, jsonMode));
+                }
+                task.getTaskParameters().clear();
+                return result;
+            }
+        } catch (final Exception e) {
+            return new ApexAPIResult(ApexAPIResult.RESULT.FAILED, e);
+        }
+    }
+
+    /**
+     * Create a task context album reference.
+     *
+     * @param name name of the task
+     * @param version version of the task, set to null to use the latest version
+     * @param contextAlbumName name of the context album for the context album reference
+     * @param contextAlbumVersion version of the context album for the context album reference, set
+     *        to null to use the latest version
+     * @return result of the operation
+     */
+    public ApexAPIResult createTaskContextRef(final String name, final String version, final String contextAlbumName,
+            final String contextAlbumVersion) {
+        try {
+            final AxTask task = apexModel.getPolicyModel().getTasks().get(name, version);
+            if (task == null) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                        CONCEPT + name + ':' + version + DOES_NOT_EXIST);
+            }
+
+            final AxContextAlbum contextAlbum =
+                    apexModel.getPolicyModel().getAlbums().get(contextAlbumName, contextAlbumVersion);
+            if (contextAlbum == null) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                        CONCEPT + contextAlbumName + ':' + contextAlbumVersion + DOES_NOT_EXIST);
+            }
+
+            if (task.getContextAlbumReferences().contains(contextAlbum.getKey())) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_EXISTS, "context album reference for concept "
+                        + contextAlbum.getKey().getID() + " already exists in task");
+            }
+
+            task.getContextAlbumReferences().add(contextAlbum.getKey());
+            return new ApexAPIResult();
+        } catch (final Exception e) {
+            return new ApexAPIResult(ApexAPIResult.RESULT.FAILED, e);
+        }
+    }
+
+    /**
+     * List task context album references.
+     *
+     * @param name name of the task
+     * @param version version of the task, set to null to use the latest version
+     * @param contextAlbumName name of the context album for the context album reference, set to
+     *        null to list all task context album references
+     * @param contextAlbumVersion version of the context album for the context album reference, set
+     *        to null to use the latest version
+     * @return result of the operation
+     */
+    public ApexAPIResult listTaskContextRef(final String name, final String version, final String contextAlbumName,
+            final String contextAlbumVersion) {
+        try {
+            final AxTask task = apexModel.getPolicyModel().getTasks().get(name, version);
+            if (task == null) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                        CONCEPT + name + ':' + version + DOES_NOT_EXIST);
+            }
+
+            final ApexAPIResult result = new ApexAPIResult();
+            boolean found = false;
+            for (final AxArtifactKey albumKey : task.getContextAlbumReferences()) {
+                if (contextAlbumName == null) {
+                    result.addMessage(new ApexModelStringWriter<AxArtifactKey>(false).writeString(albumKey,
+                            AxArtifactKey.class, jsonMode));
+                    found = true;
+                    continue;
+                }
+
+                if (!albumKey.getName().equals(contextAlbumName)) {
+                    continue;
+                }
+
+                if (contextAlbumVersion == null || albumKey.getVersion().equals(contextAlbumVersion)) {
+                    result.addMessage(new ApexModelStringWriter<AxArtifactKey>(false).writeString(albumKey,
+                            AxArtifactKey.class, jsonMode));
+                    found = true;
+                }
+            }
+            if (!found) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                        CONCEPT + contextAlbumName + ':' + contextAlbumVersion + DOES_NOT_EXIST);
+            }
+            return result;
+        } catch (final Exception e) {
+            return new ApexAPIResult(ApexAPIResult.RESULT.FAILED, e);
+        }
+    }
+
+    /**
+     * Delete a task context album reference.
+     *
+     * @param name name of the task
+     * @param version version of the task, set to null to use the latest version
+     * @param contextAlbumName name of the context album for the context album reference, set to
+     *        null to delete all task context album references
+     * @param contextAlbumVersion version of the context album for the context album reference, set
+     *        to null to use the latest version
+     * @return result of the operation
+     */
+    public ApexAPIResult deleteTaskContextRef(final String name, final String version, final String contextAlbumName,
+            final String contextAlbumVersion) {
+        try {
+            final AxTask task = apexModel.getPolicyModel().getTasks().get(name, version);
+            if (task == null) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                        CONCEPT + name + ':' + version + DOES_NOT_EXIST);
+            }
+
+            final Set<AxArtifactKey> deleteSet = new TreeSet<>();
+
+            for (final AxArtifactKey albumKey : task.getContextAlbumReferences()) {
+                if (contextAlbumName == null) {
+                    deleteSet.add(albumKey);
+                    continue;
+                }
+
+                if (!albumKey.getName().equals(contextAlbumName)) {
+                    continue;
+                }
+
+                if (contextAlbumVersion == null || albumKey.getVersion().equals(contextAlbumVersion)) {
+                    deleteSet.add(albumKey);
+                }
+            }
+
+            if (deleteSet.isEmpty()) {
+                return new ApexAPIResult(ApexAPIResult.RESULT.CONCEPT_DOES_NOT_EXIST,
+                        CONCEPT + contextAlbumName + ':' + contextAlbumVersion + DOES_NOT_EXIST);
+            }
+            final ApexAPIResult result = new ApexAPIResult();
+            for (final AxArtifactKey keyToDelete : deleteSet) {
+                task.getContextAlbumReferences().remove(keyToDelete);
+                result.addMessage(new ApexModelStringWriter<AxArtifactKey>(false).writeString(keyToDelete,
+                        AxArtifactKey.class, jsonMode));
+            }
+            return result;
+        } catch (final Exception e) {
+            return new ApexAPIResult(ApexAPIResult.RESULT.FAILED, e);
+        }
+    }
+}
diff --git a/model/model-api/src/main/java/org/onap/policy/apex/model/modelapi/impl/package-info.java b/model/model-api/src/main/java/org/onap/policy/apex/model/modelapi/impl/package-info.java
new file mode 100644
index 000000000..f31542044
--- /dev/null
+++ b/model/model-api/src/main/java/org/onap/policy/apex/model/modelapi/impl/package-info.java
@@ -0,0 +1,27 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2016-2018 Ericsson. 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 or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * 
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+/**
+ * Provides an implementation of the APEX Model API that holds an APEX model and manipulates its
+ * various parts in response to operations called over the Model API.
+ * 
+ * @author Liam Fallon (liam.fallon@ericsson.com)
+ */
+package org.onap.policy.apex.model.modelapi.impl;
diff --git a/model/model-api/src/main/java/org/onap/policy/apex/model/modelapi/package-info.java b/model/model-api/src/main/java/org/onap/policy/apex/model/modelapi/package-info.java
new file mode 100644
index 000000000..97e8db4ea
--- /dev/null
+++ b/model/model-api/src/main/java/org/onap/policy/apex/model/modelapi/package-info.java
@@ -0,0 +1,27 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2016-2018 Ericsson. 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 or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * 
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+/**
+ * Provides an API to APEX models so that they can be manipulated over a common interface by CLI and
+ * GUI based editors and other development tools.
+ * 
+ * @author Liam Fallon (liam.fallon@ericsson.com)
+ */
+package org.onap.policy.apex.model.modelapi;