diff --git a/app/Http/Controllers/API/v2/CategoryController.php b/app/Http/Controllers/API/v2/CategoryController.php
index d453459..0a698ec 100644
--- a/app/Http/Controllers/API/v2/CategoryController.php
+++ b/app/Http/Controllers/API/v2/CategoryController.php
@@ -26,19 +26,19 @@ class CategoryController extends Controller
      */
     public function index(Request $request)
     {
-        $matrix_username = $request->input('matrix_username') ?? '';
-        $company_uuid = $request->input('uuid') ?? '';
+        $matrixUsername = $request->input('matrixUsername') ?? '';
+        $companyUUID = $request->input('uuid') ?? '';
         $user = null;
         $cart = null;
         $company = null;
 
-        if($company_uuid != ''){
-            $company = Company::where('uuid', $company_uuid)->first();
+        if($companyUUID != ''){
+            $company = Company::where('uuid', $companyUUID)->first();
         }
 
-        if($matrix_username) {
+        if($matrixUsername) {
             $user = User::firstOrCreate([
-                'matrix_username' => $matrix_username
+                'matrix_username' => $matrixUsername
             ]);
 
             $cart = Cart::firstOrCreate([
@@ -47,7 +47,7 @@ class CategoryController extends Controller
             ]);
 
             $company = $cart->getCompany();
-            $company_uuid = $company->uuid;
+            $companyUUID = $company->uuid;
         }
 
         if(!$company)
@@ -59,7 +59,7 @@ class CategoryController extends Controller
         $fetcher = new ApiFetcher();
         $categoryItemAPI = new CategoryItemAPI($fetcher);
 
-        $categoriesItemsMap = $categoryItemAPI->getMap($company_uuid);
+        $categoriesItemsMap = $categoryItemAPI->getMap($companyUUID);
         $categoryItemAPI->saveMap($categoriesItemsMap, $company);
 
         // Companies Categories
diff --git a/app/Http/Controllers/API/v2/CompanyController.php b/app/Http/Controllers/API/v2/CompanyController.php
index 94fd907..7ce5285 100644
--- a/app/Http/Controllers/API/v2/CompanyController.php
+++ b/app/Http/Controllers/API/v2/CompanyController.php
@@ -26,35 +26,36 @@ class CompanyController extends Controller
      */
     public function index(Request $request)
     {
-        $matrix_username = $request->input('matrix_username') ?? '';
-        $city_uuid = $request->input('uuid') ?? '';
+        $matrixUsername = $request->input('matrixUsername') ?? '';
+        $cityUUID = $request->input('uuid') ?? '';
         $user = null;
         $cart = null;
         $city = null;
 
-        if($city_uuid != ''){
-            $city = City::where('uuid', $city_uuid)->first();
+        if($cityUUID != ''){
+            $city = City::where('uuid', $cityUUID)->first();
         }
 
-        if($matrix_username) {
+        if($matrixUsername) {
             $user = User::firstOrCreate([
-                'matrix_username' => $matrix_username
+                'matrix_username' => $matrixUsername
             ]);
 
+            // TODO valid city exists
             $cart = Cart::firstOrCreate([
                 'user_id' => $user->id,
                 'status' => 'CART'
             ]);
 
             $city = $cart->getCity();
-            $city_uuid = $city->uuid;
+            $cityUUID = $city->uuid;
         }
 
         // Update list of companies
         $fetcher = new ApiFetcher();
         $companyAPI = new CompanyAPI($fetcher);
 
-        $companyMap = $companyAPI->getMap($city_uuid);
+        $companyMap = $companyAPI->getMap($cityUUID);
         $companyAPI->saveMap($companyMap, $city);
 
         $companies = $city->getCompanies();
diff --git a/app/Http/Controllers/API/v2/UserController.php b/app/Http/Controllers/API/v2/UserController.php
index 2dcc55b..6bd9e40 100644
--- a/app/Http/Controllers/API/v2/UserController.php
+++ b/app/Http/Controllers/API/v2/UserController.php
@@ -12,7 +12,7 @@ class UserController extends Controller
     public function register(Request $request)
     {
         $username = $request->input('username') ?? '';
-        $matrix_username = $request->input('matrix_username') ?? '';
+        $matrixUsername = $request->input('matrixUsername') ?? '';
         $phone = $request->input('phone') ?? '';
 
         if($username == '') {
@@ -26,7 +26,7 @@ class UserController extends Controller
             // if username is free then the new user will be created
             // with addition arguments:
             [
-                'matrix_username' => $matrix_username,
+                'matrix_username' => $matrixUsername,
                 'phone' => $phone
             ]
         );
@@ -45,7 +45,7 @@ class UserController extends Controller
     public function login(Request $request)
     {
         $username = $request->input('username') ?? '';
-        $matrix_username = $request->input('matrix_username') ?? '';
+        $matrixUsername = $request->input('matrixUsername') ?? '';
 
         if($username == '') {
             return response()->json([
@@ -63,8 +63,8 @@ class UserController extends Controller
 
         // Update matrix user if needed
         // TODO add verification check
-        if($user->matrix_username != $matrix_username) {
-            $user->matrix_username = $matrix_username;
+        if($user->matrix_username != $matrixUsername) {
+            $user->matrix_username = $matrixUsername;
             $user->save();
         }
 
diff --git a/tests/Feature/UserTest.php b/tests/Feature/UserTest.php
index 2a54504..e8797ff 100644
--- a/tests/Feature/UserTest.php
+++ b/tests/Feature/UserTest.php
@@ -14,10 +14,10 @@ use App\Models\User;
 class UserTest extends TestCase
 {
     protected $username = 'Oleg';
-    protected $matrix_username = '@oleg:oleg.com';
+    protected $matrixUsername = '@oleg:oleg.com';
     protected $phone = '380671231212';
 
-    protected $not_existing_user = [
+    protected $notExistingUser = [
         'username' => 'Kostia',
         'matrix_username' => '@kostia:kostia.com',
     ];
@@ -26,7 +26,7 @@ class UserTest extends TestCase
     {
         $response = $this->post('/api/v2/register', [
             'username' => $this->username,
-            'matrix_username' => $this->matrix_username,
+            'matrix_username' => $this->matrixUsername,
             'phone' => $this->phone,
         ]);
 
@@ -45,7 +45,7 @@ class UserTest extends TestCase
     {
         $response = $this->post('/api/v2/register', [
             'username' => $this->username,
-            'matrix_username' => $this->matrix_username,
+            'matrix_username' => $this->matrixUsername,
             'phone' => $this->phone,
         ]);
 
@@ -58,7 +58,7 @@ class UserTest extends TestCase
 
     public function test_login_not_existing_user(): void
     {
-        $response = $this->post('/api/v2/login', $this->not_existing_user);
+        $response = $this->post('/api/v2/login', $this->notExistingUser);
 
         $response->assertStatus(200);
 
@@ -71,7 +71,7 @@ class UserTest extends TestCase
     {
         $response = $this->post('/api/v2/login', [
             'username' => $this->username,
-            'matrix_username' => $this->matrix_username,
+            'matrix_username' => $this->matrixUsername,
         ]);
 
         $response->assertStatus(200);
@@ -102,18 +102,18 @@ class UserTest extends TestCase
 
     public function test_not_existing_user_with_matrix_username(): void
     {
-        $matrix_username = '@kostia:test.com';
+        $matrixUsername = '@kostia:test.com';
 
-        $json = User::validate_with_matrix_username($matrix_username);
+        $json = User::validate_with_matrix_username($matrixUsername);
 
         $this->assertEquals($json['error'], 'A user with the username does not exist!!!');
     }
 
     public function test_valid_user_with_matrix_username(): void
     {
-        $matrix_username = '@test:test.com';
+        $matrixUsername = '@test:test.com';
 
-        $json = User::validate_with_matrix_username($matrix_username);
+        $json = User::validate_with_matrix_username($matrixUsername);
 
         $this->assertEquals($json['ok'], 'A user with the username is valid.');
     }