--- title: Node class description: Implement the Node interface to create custom authentication nodes that access shared state, request user input through callbacks, and define exit paths in PingAM authentication trees component: pingam version: 7.5 page_id: pingam:auth-nodes:core-class canonical_url: https://docs.pingidentity.com/pingam/8.1/auth-nodes/core-class.html llms_txt: https://docs.pingidentity.com/pingam/llms.txt docs_for_agents: https://developer.pingidentity.com/build-with-ai/docs-for-agents.md keywords: ["Extensibility", "Nodes & Trees", "Scripts"] superseded_by: https://docs.pingidentity.com/pingam/8.1/auth-nodes/core-class.html --- # Node class The `Node` class can access and modify the persisted state shared between the nodes within a tree, and can request input by using callbacks. The class also defines the possible exit paths from the node. In Java terms, an authentication node is a class that implements the `Node` interface, `org.forgerock.openam.auth.node.api.Node`. The `SetSessionProperties` class shows the steps to implement the Node interface: ```java package org.forgerock.openam.auth.nodes; import java.util.Map; import javax.inject.Inject; import org.forgerock.openam.annotations.sm.Attribute; import org.forgerock.openam.auth.node.api.Action; import org.forgerock.openam.auth.node.api.Node; import org.forgerock.openam.auth.node.api.SingleOutcomeNode; import org.forgerock.openam.auth.node.api.TreeContext; import org.forgerock.openam.auth.nodes.validators.SessionPropertyValidator; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import com.google.inject.assistedinject.Assisted; /* * A node that defines a configurable set of properties to add to * the user's session if/when it is created. */ @Node.Metadata(outcomeProvider = SingleOutcomeNode.OutcomeProvider.class, configClass = SetSessionPropertiesNode.Config.class, tags = {"utilities"}) 1 public class SetSessionPropertiesNode extends SingleOutcomeNode { 2 / * Configuration for the node. / public interface Config { 3 / * A map of property name to value. * @return a map of properties. / @Attribute(order = 100, validators = SessionPropertyValidator.class) Map properties(); } private final Config config; 4 private final Logger logger = LoggerFactory.getLogger("SetSessionPropertiesNode.class"); / * Constructs a new SetSessionPropertiesNode instance. * @param config Node configuration. */ @Inject 5 public SetSessionPropertiesNode(@Assisted Config config) { this.config = config; } @Override public Action process(TreeContext context) { 6 logger.debug("SetSessionPropertiesNode started"); Action.ActionBuilder actionBuilder = goToNext(); config.properties().entrySet().forEach(property → { actionBuilder.putSessionProperty(property.getKey(), property.getValue()); logger.debug("set session property {}", property); }); return actionBuilder.build(); } } ``` | Step | Description | Further information | | --------------------------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | 1 Apply the `@Node.Metadata` annotation | The *annotation* specifies the outcome provider, configuration class, and optionally, the configuration validation class and tags.Use an existing outcome provider such as `SingleOutcomeNode.OutcomeProvider` or `AbstractDecisionNode.OutcomeProvider`, or create a custom provider and reference the class from the annotation. | [Metadata annotation](core-metadata.html) | | 2 Implement the `Node` interface | Extend one of the following abstract classes to implement the `Node` interface:- `SingleOutcomeNode` For nodes with a single exit path; for example [Modify Auth Level node](https://docs.pingidentity.com/auth-node-ref/7.5/modify-auth-level.html). - `AbstractDecisionNode` For nodes with a boolean-type exit path (true/false, allow/deny); for example, [Data Store Decision node](https://docs.pingidentity.com/auth-node-ref/7.5/data-store-decision.html).Alternatively, write your own implementation of the `Node` interface to define custom exit paths. | Javadoc:- [Node](../_attachments/apidocs/org/forgerock/openam/auth/node/api/Node.html) interface - [AbstractDecisionNode](../_attachments/apidocs/org/forgerock/openam/auth/node/api/AbstractDecisionNode.html) class - [SingleOutcomeNode](../_attachments/apidocs/org/forgerock/openam/auth/node/api/SingleOutcomeNode.html) class | | 3 Implement the `Config` interface | The `Config` interface defines the configuration data for a node. | [Config interface](core-config.html) | | 4 Define private constants and methods | *Optional* | | | 5 Inject dependencies | Inject objects using Guice as this makes it easier to unit test your node.This example specifies `config` as a parameter. You can also include supported AM classes, instances of third-party dependencies, or your own types. | [Inject objects into a node instance](core-inject.html). | | 6 Override the `process` method | The `process` method is where you store and retrieve state if required.It takes a `TreeContext` parameter that you can use to access the request, callbacks, shared state and other input.The method returns an `Action` object. This can be a response of callback to the user, an update of state, or a choice of outcome. The `Action` object encapsulates changes to state and flow control.The choice of outcome in a simple decision node would be `true` or `false`, resulting in the authentication tree flow moving from the current node to a node at the relevant connection. | [Action class](core-action.html). |