diff --git a/backend/modules/api/Api.php b/backend/modules/api/Api.php
new file mode 100644
index 0000000..fd7935e
--- /dev/null
+++ b/backend/modules/api/Api.php
@@ -0,0 +1,24 @@
+<?php
+
+namespace backend\modules\api;
+
+/**
+ * api module definition class
+ */
+class Api extends \yii\base\Module
+{
+    /**
+     * {@inheritdoc}
+     */
+    public $controllerNamespace = 'backend\modules\api\controllers';
+
+    /**
+     * {@inheritdoc}
+     */
+    public function init()
+    {
+        parent::init();
+
+        // custom initialization code goes here
+    }
+}
diff --git a/backend/modules/api/controllers/DefaultController.php b/backend/modules/api/controllers/DefaultController.php
new file mode 100644
index 0000000..a6a73f3
--- /dev/null
+++ b/backend/modules/api/controllers/DefaultController.php
@@ -0,0 +1,20 @@
+<?php
+
+namespace backend\modules\api\controllers;
+
+use yii\web\Controller;
+
+/**
+ * Default controller for the `api` module
+ */
+class DefaultController extends Controller
+{
+    /**
+     * Renders the index view for the module
+     * @return string
+     */
+    public function actionIndex()
+    {
+        return $this->render('index');
+    }
+}
diff --git a/backend/modules/api/controllers/UserQuestionnaireController.php b/backend/modules/api/controllers/UserQuestionnaireController.php
new file mode 100644
index 0000000..e0c148b
--- /dev/null
+++ b/backend/modules/api/controllers/UserQuestionnaireController.php
@@ -0,0 +1,49 @@
+<?php
+
+namespace backend\modules\api\controllers;
+
+use yii\filters\auth\CompositeAuth;
+use yii\filters\auth\HttpBearerAuth;
+use yii\rest\Controller;
+
+class UserQuestionnaireController extends Controller
+{
+    public $modelClass = 'backend/modules/api/models/UserQuestionnaire';
+
+
+    public function behaviors()
+    {
+        return [
+            [
+                'class' => \yii\filters\ContentNegotiator::className(),
+                'formats' => [
+                    'application/json' => \yii\web\Response::FORMAT_JSON,
+                ],
+            ],
+//            'authenticator' => [
+//                'class' => CompositeAuth::class,
+//                'authMethods' => [
+//                    HttpBearerAuth::class,
+//                ],
+//            ]
+        ];
+    }
+
+    public function actionIndex()
+    {
+        return ['some' => 'rrr'];
+    }
+
+//    /**
+//     * @inheritdoc
+//     */
+//    protected function verbs()
+//    {
+//        return [
+//            'index' => ['GET', 'HEAD'],
+//        ];
+//    }
+
+
+
+}
diff --git a/backend/modules/api/models/User.php b/backend/modules/api/models/User.php
new file mode 100644
index 0000000..ecdf04e
--- /dev/null
+++ b/backend/modules/api/models/User.php
@@ -0,0 +1,96 @@
+<?php
+
+namespace backend\modules\api\models;
+
+use Yii;
+
+/**
+ * This is the model class for table "user".
+ *
+ * @property int $id
+ * @property string $username
+ * @property string $auth_key
+ * @property string $password_hash
+ * @property string $password_reset_token
+ * @property string $email
+ * @property int $status
+ * @property int $created_at
+ * @property int $updated_at
+ * @property string $access_token
+ * @property string $access_token_expired_at
+ *
+ * @property UserCard[] $userCards
+ * @property UserQuestionnaire[] $userQuestionnaires
+ * @property UserResponse[] $userResponses
+ */
+class User extends \common\models\User
+{
+    /**
+     * {@inheritdoc}
+     */
+    public static function tableName()
+    {
+        return 'user';
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function rules()
+    {
+        return [
+            [['username', 'auth_key', 'password_hash', 'email', 'created_at', 'updated_at'], 'required'],
+            [['status', 'created_at', 'updated_at'], 'integer'],
+            [['access_token_expired_at'], 'safe'],
+            [['username', 'password_hash', 'password_reset_token', 'email', 'access_token'], 'string', 'max' => 255],
+            [['auth_key'], 'string', 'max' => 32],
+            [['username'], 'unique'],
+            [['email'], 'unique'],
+            [['password_reset_token'], 'unique'],
+        ];
+    }
+
+    /**
+     * {@inheritdoc}
+     */
+    public function attributeLabels()
+    {
+        return [
+            'id' => 'ID',
+            'username' => 'Username',
+            'auth_key' => 'Auth Key',
+            'password_hash' => 'Password Hash',
+            'password_reset_token' => 'Password Reset Token',
+            'email' => 'Email',
+            'status' => 'Status',
+            'created_at' => 'Created At',
+            'updated_at' => 'Updated At',
+            'access_token' => 'Access Token',
+            'access_token_expired_at' => 'Access Token Expired At',
+        ];
+    }
+
+    /**
+     * @return \yii\db\ActiveQuery
+     */
+    public function getUserCards()
+    {
+        return $this->hasMany(UserCard::className(), ['id_user' => 'id']);
+    }
+
+    /**
+     * @return \yii\db\ActiveQuery
+     */
+    public function getUserQuestionnaires()
+    {
+        return $this->hasMany(UserQuestionnaire::className(), ['user_id' => 'id']);
+    }
+
+    /**
+     * @return \yii\db\ActiveQuery
+     */
+    public function getUserResponses()
+    {
+        return $this->hasMany(UserResponse::className(), ['user_id' => 'id']);
+    }
+}
diff --git a/backend/modules/api/models/UserQuestionnaire.php b/backend/modules/api/models/UserQuestionnaire.php
new file mode 100644
index 0000000..ee0ae51
--- /dev/null
+++ b/backend/modules/api/models/UserQuestionnaire.php
@@ -0,0 +1,9 @@
+<?php
+
+namespace backend\modules\api\models;
+
+
+class UserQuestionnaire extends \common\models\UserQuestionnaire
+{
+
+}
diff --git a/backend/modules/api/views/default/index.php b/backend/modules/api/views/default/index.php
new file mode 100644
index 0000000..aa260c4
--- /dev/null
+++ b/backend/modules/api/views/default/index.php
@@ -0,0 +1,12 @@
+<div class="api-default-index">
+    <h1><?= $this->context->action->uniqueId ?></h1>
+    <p>
+        This is the view content for action "<?= $this->context->action->id ?>".
+        The action belongs to the controller "<?= get_class($this->context) ?>"
+        in the "<?= $this->context->module->id ?>" module.
+    </p>
+    <p>
+        You may customize this page by editing the following file:<br>
+        <code><?= __FILE__ ?></code>
+    </p>
+</div>
diff --git a/backend/modules/api/views/user-questionnaire/index.php b/backend/modules/api/views/user-questionnaire/index.php
new file mode 100644
index 0000000..d1e0ec8
--- /dev/null
+++ b/backend/modules/api/views/user-questionnaire/index.php
@@ -0,0 +1,9 @@
+<?php
+/* @var $this yii\web\View */
+?>
+<h1>user-questionnaire/index</h1>
+
+<p>
+    You may change the content of this page by modifying
+    the file <code><?= __FILE__; ?></code>.
+</p>
diff --git a/backend/views/question/index.php b/backend/views/question/index.php
new file mode 100644
index 0000000..575655c
--- /dev/null
+++ b/backend/views/question/index.php
@@ -0,0 +1,9 @@
+<?php
+/* @var $this yii\web\View */
+?>
+<h1>question/index</h1>
+
+<p>
+    You may change the content of this page by modifying
+    the file <code><?= __FILE__; ?></code>.
+</p>
diff --git a/frontend/modules/api/controllers/AnswerController.php b/frontend/modules/api/controllers/AnswerController.php
new file mode 100644
index 0000000..5f12372
--- /dev/null
+++ b/frontend/modules/api/controllers/AnswerController.php
@@ -0,0 +1,58 @@
+<?php
+
+namespace frontend\modules\api\controllers;
+
+use common\models\Answer;
+use Yii;
+use yii\filters\auth\HttpBearerAuth;
+use yii\web\NotFoundHttpException;
+use yii\rest\Controller;
+
+class AnswerController extends Controller
+{
+    public function behaviors(): array
+    {
+        $behaviors = parent::behaviors();
+
+        $behaviors['authenticator']['authMethods'] = [
+            HttpBearerAuth::className(),
+        ];
+
+        return $behaviors;
+    }
+
+    public function verbs(): array
+    {
+        return [
+            'get-answers' => ['get'],
+        ];
+    }
+
+    /**
+     * @throws NotFoundHttpException
+     */
+    public function actionGetAnswers(): array
+    {
+        $question_id = Yii::$app->request->get('question_id');
+
+        if(empty($question_id) or !is_numeric($question_id))
+        {
+            throw new NotFoundHttpException('Incorrect questionnaire ID');
+        }
+
+        $answers = Answer::getActiveAnswers($question_id);
+        if(empty($answers)) {
+            throw new NotFoundHttpException('Active questionnaire not found');
+        }
+
+        array_walk( $answers, function(&$arr){
+            unset(
+                $arr['created_at'],
+                $arr['updated_at'],
+                $arr['answer_flag']
+            );
+        });
+
+        return  $answers;
+    }
+}
diff --git a/frontend/modules/api/controllers/QuestionController.php b/frontend/modules/api/controllers/QuestionController.php
new file mode 100644
index 0000000..ef72fa2
--- /dev/null
+++ b/frontend/modules/api/controllers/QuestionController.php
@@ -0,0 +1,60 @@
+<?php
+
+namespace frontend\modules\api\controllers;
+
+use common\models\Question;
+use common\models\Questionnaire;
+use Yii;
+use yii\filters\auth\HttpBearerAuth;
+use yii\web\NotFoundHttpException;
+
+class QuestionController extends \yii\rest\Controller
+{
+    public function behaviors()
+    {
+        $behaviors = parent::behaviors();
+
+        $behaviors['authenticator']['authMethods'] = [
+            HttpBearerAuth::className(),
+        ];
+
+        return $behaviors;
+    }
+
+    public function verbs()
+    {
+        return [
+            'get-questions' => ['get'],
+        ];
+    }
+
+    /**
+     * @throws NotFoundHttpException
+     */
+    public function actionGetQuestions()
+    {
+        $questionnaire_id = Yii::$app->request->get('questionnaire_id');
+
+        if(empty($questionnaire_id) or !is_numeric($questionnaire_id))
+        {
+            throw new NotFoundHttpException('Incorrect questionnaire ID');
+        }
+
+        $questions = Question::getActiveQuestions($questionnaire_id);
+        if(empty($questions)) {
+            throw new NotFoundHttpException('Active questionnaire not found');
+        }
+
+        array_walk( $questions, function(&$arr){
+            unset(
+                $arr['score'],
+                $arr['created_at'],
+                $arr['updated_at'],
+                $arr['status'],
+            );
+        });
+
+        return  $questions;
+    }
+
+}
diff --git a/frontend/modules/api/controllers/UserQuestionnaireController.php b/frontend/modules/api/controllers/UserQuestionnaireController.php
new file mode 100644
index 0000000..47b4201
--- /dev/null
+++ b/frontend/modules/api/controllers/UserQuestionnaireController.php
@@ -0,0 +1,60 @@
+<?php
+
+namespace frontend\modules\api\controllers;
+
+use common\models\UserQuestionnaire;
+use Yii;
+use yii\filters\auth\HttpBearerAuth;
+use yii\rest\Controller;
+use yii\web\NotFoundHttpException;
+
+class UserQuestionnaireController extends Controller
+{
+    public function behaviors()
+    {
+        $behaviors = parent::behaviors();
+
+        $behaviors['authenticator']['authMethods'] = [
+            HttpBearerAuth::className(),
+        ];
+
+        return $behaviors;
+    }
+
+    public function verbs()
+    {
+        return [
+            'questionnaires-list' => ['get'],
+        ];
+    }
+
+    /**
+     * @throws NotFoundHttpException
+     */
+    public function actionQuestionnairesList(): array
+    {
+        $user_id = Yii::$app->request->get('user_id');
+
+        if(empty($user_id) or !is_numeric($user_id))
+        {
+            throw new NotFoundHttpException('Incorrect user ID');
+        }
+
+        $userQuestionnaireModel = UserQuestionnaire::findActiveUserQuestionnaires($user_id);
+        if(empty($userQuestionnaireModel)) {
+            throw new NotFoundHttpException('Active questionnaire not found');
+        }
+
+        array_walk( $userQuestionnaireModel, function(&$arr){
+            unset(
+                $arr['uuid'],
+                $arr['created_at'],
+                $arr['updated_at'],
+                $arr['score'],
+                $arr['percent_correct_answers']
+            );
+        });
+
+        return  $userQuestionnaireModel;
+    }
+}
diff --git a/frontend/modules/api/controllers/UserResponseController.php b/frontend/modules/api/controllers/UserResponseController.php
new file mode 100644
index 0000000..013afd9
--- /dev/null
+++ b/frontend/modules/api/controllers/UserResponseController.php
@@ -0,0 +1,60 @@
+<?php
+
+namespace frontend\modules\api\controllers;
+
+use common\models\Reports;
+use common\models\UserResponse;
+use Yii;
+use yii\filters\auth\HttpBearerAuth;
+use yii\helpers\Url;
+use yii\rest\ActiveController;
+use yii\web\BadRequestHttpException;
+use yii\web\ServerErrorHttpException;
+
+class UserResponseController extends \yii\rest\ActiveController
+{
+    public $modelClass = 'common\models\UserResponse';
+
+    public function behaviors(): array
+    {
+        $behaviors = parent::behaviors();
+
+        $behaviors['authenticator']['authMethods'] = [
+            HttpBearerAuth::className(),
+        ];
+
+        return $behaviors;
+    }
+
+    public function verbs(): array
+    {
+        return [
+//            'set-responses' => ['post'],
+            'create' => ['post'],
+        ];
+    }
+
+    public function actions()
+    {
+        $actions = parent::actions();
+        unset($actions['create']);
+        return $actions;
+    }
+
+    public function actionCreate()
+    {
+        $model = new UserResponse();
+
+        $model->load(Yii::$app->getRequest()->getBodyParams(), '');
+        if ($model->save()) {
+            $response = Yii::$app->getResponse();
+            $response->setStatusCode(201);
+//            $id = implode(',', array_values($model->getPrimaryKey(true)));
+//            $response->getHeaders()->set('Location', Url::toRoute(['view', 'id' => $id], true));
+        } elseif (!$model->hasErrors()) {
+            throw new ServerErrorHttpException('Failed to create the object for unknown reason.');
+        }
+
+        return $model;
+    }
+}