diff --git a/LaunchServer/runtime/plugin.js b/LaunchServer/runtime/plugin.js
index 7ec484a..495594a 100644
--- a/LaunchServer/runtime/plugin.js
+++ b/LaunchServer/runtime/plugin.js
@@ -1,4 +1,35 @@
 server.loadScript(IOHelperClass.static.toURL(java.nio.file.Paths.get("apiServer.js")));
 
 // Print test message
-LogHelper.info("This message was printed from plugin.js");
+LogHelper.info("[plugin.js] Test message");
+
+// Register command
+server.commandHandler.registerCommand("test", new (Java.extend(Command, {
+	getArgsDescription: function() { return "[anything]"; },
+	getUsageDescription: function() { return "plugin.js test command"; },
+	
+	invoke: function(args) {
+		LogHelper.info("[plugin.js] Command invoked! Args: " +
+			java.util.Arrays.toString(args));
+	}
+}))(server));
+
+// Register custom response
+server.serverSocketHandler.registerCustomResponse("test", function(server, input, output) {
+	return new (Java.extend(Response, function() {
+		LogHelper.info("[plugin.js] Custom response invoked!");
+		output.writeInt(0x724);
+	}))(server, input, output);
+});
+
+/* You can test custom request like this:
+var TestCustomRequest = Java.extend(CustomRequest, {
+	getName: function() { return "test"; },
+	
+	requestDoCustom: function(input, output) {
+		return input.readInt();
+	}
+});
+var answer = new TestCustomRequest().request();
+LogHelper.info(Integer.toHexString(answer));
+*/
\ No newline at end of file
diff --git a/LaunchServer/source/LaunchServer.java b/LaunchServer/source/LaunchServer.java
index a1b4007..20fcd1e 100644
--- a/LaunchServer/source/LaunchServer.java
+++ b/LaunchServer/source/LaunchServer.java
@@ -66,6 +66,7 @@
 import launchserver.command.handler.CommandHandler;
 import launchserver.command.handler.JLineCommandHandler;
 import launchserver.command.handler.StdCommandHandler;
+import launchserver.response.Response;
 import launchserver.response.ServerSocketHandler;
 
 public final class LaunchServer implements Runnable {
@@ -432,8 +433,8 @@
 		bindings.put("CommandExceptionClass", CommandException.class);
 
 		// Set response class bindings
-		bindings.put("ResponseClass", Command.class);
-		bindings.put("ResponseFactoryClass", CommandHandler.class);
+		bindings.put("ResponseClass", Response.class);
+		bindings.put("ResponseFactoryClass", Response.Factory.class);
 	}
 
 	private final class ProfilesFileVisitor extends SimpleFileVisitor<Path> {
diff --git a/LaunchServer/source/command/handler/CommandHandler.java b/LaunchServer/source/command/handler/CommandHandler.java
index a0888f4..46dfc6a 100644
--- a/LaunchServer/source/command/handler/CommandHandler.java
+++ b/LaunchServer/source/command/handler/CommandHandler.java
@@ -45,31 +45,31 @@
 
 	protected CommandHandler(LaunchServer server) {
 		// Register basic commands
-		register("help", new HelpCommand(server));
-		register("version", new VersionCommand(server));
-		register("build", new BuildCommand(server));
-		register("stop", new StopCommand(server));
-		register("rebind", new RebindCommand(server));
-		register("reloadConfig", new ReloadConfigCommand(server));
-		register("reloadKeyPair", new ReloadKeyPairCommand(server));
-		register("eval", new EvalCommand(server));
-		register("debug", new DebugCommand(server));
-		register("clear", new ClearCommand(server));
-		register("gc", new GCCommand(server));
+		registerCommand("help", new HelpCommand(server));
+		registerCommand("version", new VersionCommand(server));
+		registerCommand("build", new BuildCommand(server));
+		registerCommand("stop", new StopCommand(server));
+		registerCommand("rebind", new RebindCommand(server));
+		registerCommand("reloadConfig", new ReloadConfigCommand(server));
+		registerCommand("reloadKeyPair", new ReloadKeyPairCommand(server));
+		registerCommand("eval", new EvalCommand(server));
+		registerCommand("debug", new DebugCommand(server));
+		registerCommand("clear", new ClearCommand(server));
+		registerCommand("gc", new GCCommand(server));
 
 		// Register sync commands
-		register("indexAsset", new IndexAssetCommand(server));
-		register("unindexAsset", new UnindexAssetCommand(server));
-		register("downloadAsset", new DownloadAssetCommand(server));
-		register("downloadClient", new DownloadClientCommand(server));
-		register("syncBinaries", new SyncBinariesCommand(server));
-		register("syncUpdates", new SyncUpdatesCommand(server));
-		register("syncProfiles", new SyncProfilesCommand(server));
+		registerCommand("indexAsset", new IndexAssetCommand(server));
+		registerCommand("unindexAsset", new UnindexAssetCommand(server));
+		registerCommand("downloadAsset", new DownloadAssetCommand(server));
+		registerCommand("downloadClient", new DownloadClientCommand(server));
+		registerCommand("syncBinaries", new SyncBinariesCommand(server));
+		registerCommand("syncUpdates", new SyncUpdatesCommand(server));
+		registerCommand("syncProfiles", new SyncProfilesCommand(server));
 
 		// Register auth commands
-		register("auth", new AuthCommand(server));
-		register("usernameToUUID", new UsernameToUUIDCommand(server));
-		register("uuidToUsername", new UUIDToUsernameCommand(server));
+		registerCommand("auth", new AuthCommand(server));
+		registerCommand("usernameToUUID", new UsernameToUUIDCommand(server));
+		registerCommand("uuidToUsername", new UUIDToUsernameCommand(server));
 	}
 
 	@Override
@@ -132,7 +132,7 @@
 	public abstract String readLine() throws IOException;
 
 	@LauncherAPI
-	public final void register(String name, Command command) {
+	public final void registerCommand(String name, Command command) {
 		VerifyHelper.verifyIDName(name);
 		VerifyHelper.putIfAbsent(commands, name, Objects.requireNonNull(command, "command"),
 			String.format("Command has been already registered: '%s'", name));