Get Extension API during initialization

src/main/java/org/opensearch/sdk/ExtensionSettings.java

@@ -7,6 +7,8 @@
  */
 package org.opensearch.sdk;
 
+import java.util.List;
+
 /**
  * This class encapsulates the settings for an Extension.
  */
@@ -15,6 +17,7 @@ public class ExtensionSettings {
     private String extensionName;
     private String hostAddress;
     private String hostPort;
+    private List<String> api;
 
     /**
      * Placeholder field. Change the location to extension.yml file of the extension.
@@ -40,9 +43,20 @@ public String getHostPort() {
         return hostPort;
     }
 
+    public List<String> getApi() {
+        return api;
+    }
+
     @Override
     public String toString() {
-        return "\nnodename: " + extensionName + "\nhostaddress: " + hostAddress + "\nhostPort: " + hostPort + "\n";
+        return "ExtensionSettings {extensionName="
+            + extensionName
+            + ", hostAddress="
+            + hostAddress
+            + ", hostPort="
+            + hostPort
+            + ", api="
+            + api
+            + "}";
     }
-
 }

src/main/java/org/opensearch/sdk/ExtensionsRunner.java

@@ -95,11 +95,11 @@ public DiscoveryNode getOpensearchNode() {
      * Handles a plugin request from OpenSearch.  This is the first request for the transport communication and will initialize the extension and will be a part of OpenSearch bootstrap.
      *
      * @param pluginRequest  The request to handle.
-     * @return A response to OpenSearch validating that this is an extension.
+     * @return A response to OpenSearch with the extension name and API.
      */
     PluginResponse handlePluginsRequest(PluginRequest pluginRequest) {
         logger.info("Registering Plugin Request received from OpenSearch");
-        PluginResponse pluginResponse = new PluginResponse(extensionSettings.getExtensionName());
+        PluginResponse pluginResponse = new PluginResponse(extensionSettings.getExtensionName(), extensionSettings.getApi());
         opensearchNode = pluginRequest.getSourceNode();
         setOpensearchNode(opensearchNode);
         return pluginResponse;

src/test/resources/extension.yml

@@ -1,3 +1,7 @@
 extensionName: extension
 hostAddress: 127.0.0.1
 hostPort: 4532
+api:
+  - API1
+  - API2
+  - API3