logSystem-advance/api/modules/v1/controllers/SiteController.php

<?php
namespace api\modules\v1\controllers;
use yii\rest\ActiveController;
use yii\rest\Controller;

/**
 * Site controller
 */
class SiteController extends ActiveController
{
    public function actionIndex()
    {
        \Yii::$app->response->format = \yii\web\Response::FORMAT_JSON;
        return [
            'message' => 'API test Ok!',
            'code' => 100,
        ];
    }



}