diff --git a/.github/workflows/phpstan.yml b/.github/workflows/phpstan.yml
new file mode 100644
index 0000000..225a807
--- /dev/null
+++ b/.github/workflows/phpstan.yml
@@ -0,0 +1,39 @@
+name: Tests PHPStan in environments
+
+on: [pull_request]
+
+jobs:
+  php82-laravel-latest-phpstan-postgres:
+    runs-on: ubuntu-latest
+    container:
+      image: escolalms/php:8.2
+
+    services:
+      postgres:
+        image: postgres:12
+        env:
+          POSTGRES_USER: postgres
+          POSTGRES_PASSWORD: postgres
+          POSTGRES_DB: test
+          TZ: Europe/Warsaw
+        ports:
+          - 5432:5432
+
+    steps:
+      - name: Instantiate package
+        uses: actions/checkout@v2
+
+      - name: Setup environment
+        run: cp env/postgres/* .
+
+      - name: Update composer
+        run: COMPOSER_ROOT_VERSION=0.9.9 composer update
+
+      - name: Clear config
+        run: vendor/bin/testbench config:clear
+
+      - name: Publish things
+        run: vendor/bin/testbench migrate:fresh
+
+      - name: Run tests
+        run: vendor/bin/phpstan analyse
diff --git a/composer.json b/composer.json
index 933b515..f6ffc79 100644
--- a/composer.json
+++ b/composer.json
@@ -10,9 +10,10 @@
   "require-dev": {
     "barryvdh/laravel-ide-helper": "^2.12",
     "escolalms/settings": "^0.1.91",
-    "nunomaduro/collision": "^5.11",
-    "orchestra/testbench": "^5.0|^6.0",
-    "phpunit/phpunit": "^9.0"
+    "nunomaduro/collision": ">=5.11",
+    "orchestra/testbench": ">=5.0",
+    "phpunit/phpunit": "^9.0",
+    "nunomaduro/larastan": "^2.0"
   },
   "suggest": {},
   "license": "MIT",
diff --git a/phpstan.neon b/phpstan.neon
new file mode 100644
index 0000000..50a54e0
--- /dev/null
+++ b/phpstan.neon
@@ -0,0 +1,10 @@
+includes:
+    - ./vendor/nunomaduro/larastan/extension.neon
+
+parameters:
+
+    paths:
+        - src/
+
+    # The level 9 is the highest level
+    level: 6
diff --git a/src/EscolaLmsVouchersServiceProvider.php b/src/EscolaLmsVouchersServiceProvider.php
index d34de76..438f2d5 100644
--- a/src/EscolaLmsVouchersServiceProvider.php
+++ b/src/EscolaLmsVouchersServiceProvider.php
@@ -20,13 +20,16 @@ class EscolaLmsVouchersServiceProvider extends ServiceProvider
 {
     const CONFIG_KEY = 'escolalms_vouchers';
 
-    public $singletons = [
+    /**
+     * @var array<class-string, class-string>
+     */
+    public array $singletons = [
         CouponServiceContract::class => CouponService::class,
         OrderServiceContract::class => OrderService::class,
         ShopServiceContract::class => ShopService::class,
     ];
 
-    public function register()
+    public function register(): void
     {
         $this->mergeConfigFrom(__DIR__ . '/config.php', self::CONFIG_KEY);
 
@@ -40,7 +43,7 @@ public function register()
         $this->app->register(AuthServiceProvider::class);
     }
 
-    public function boot()
+    public function boot(): void
     {
         $this->loadRoutesFrom(__DIR__ . '/routes.php');
         $this->loadTranslationsFrom(__DIR__ . '/../resources/lang', 'coupon');
@@ -53,7 +56,7 @@ public function boot()
         }
     }
 
-    public function bootForConsole()
+    public function bootForConsole(): void
     {
         $this->loadMigrationsFrom(__DIR__ . '/../database/migrations');
 
diff --git a/src/Http/Controllers/VouchersAdminApiController.php b/src/Http/Controllers/VouchersAdminApiController.php
index 0434ff3..4db86d4 100644
--- a/src/Http/Controllers/VouchersAdminApiController.php
+++ b/src/Http/Controllers/VouchersAdminApiController.php
@@ -28,7 +28,7 @@ public function index(ListCouponsRequest $request): JsonResponse
         $orderDto = OrderDto::instantiateFromRequest($request);
         $searchCouponsDto = $request->toDto();
         $paginatedResults = $this->couponsService->searchAndPaginateCoupons($searchCouponsDto, $orderDto);
-        return $this->sendResponseForResource(CouponResource::collection($paginatedResults, __('Coupons search results')));
+        return $this->sendResponseForResource(CouponResource::collection($paginatedResults), ('Coupons search results'));
     }
 
     public function create(CreateCouponRequest $request): JsonResponse
diff --git a/src/Http/Controllers/VouchersApiController.php b/src/Http/Controllers/VouchersApiController.php
index 5236543..3401cb8 100644
--- a/src/Http/Controllers/VouchersApiController.php
+++ b/src/Http/Controllers/VouchersApiController.php
@@ -3,6 +3,7 @@
 namespace EscolaLms\Vouchers\Http\Controllers;
 
 use EscolaLms\Core\Http\Controllers\EscolaLmsBaseController;
+use EscolaLms\Core\Models\User;
 use EscolaLms\Vouchers\Exceptions\CouponInactiveException;
 use EscolaLms\Vouchers\Exceptions\CouponNotApplicableException;
 use EscolaLms\Vouchers\Http\Controllers\Swagger\VouchersApiControllerSwagger;
@@ -23,7 +24,9 @@ public function __construct(ShopServiceContract $shopService)
     public function apply(ApplyCouponRequest $request): JsonResponse
     {
         try {
-            $cart = $this->shopService->cartForUser($request->user());
+            /** @var User $user */
+            $user = $request->user();
+            $cart = $this->shopService->cartForUser($user);
             $cartManager = $cart->cart_manager;
             $cartManager->setCoupon($request->getCoupon());
         } catch (CouponInactiveException $ex) {
@@ -36,7 +39,9 @@ public function apply(ApplyCouponRequest $request): JsonResponse
 
     public function unapply(UnapplyCouponRequest $request): JsonResponse
     {
-        $cart = $this->shopService->cartForUser($request->user());
+        /** @var User $user */
+        $user = $request->user();
+        $cart = $this->shopService->cartForUser($user);
         $cartManager = $cart->cart_manager;
         $cartManager->removeCoupon();
         return $this->sendSuccess(__("Coupon removed from cart"));
diff --git a/src/Http/Requests/ApplyCouponRequest.php b/src/Http/Requests/ApplyCouponRequest.php
index f93dff9..01ffea7 100644
--- a/src/Http/Requests/ApplyCouponRequest.php
+++ b/src/Http/Requests/ApplyCouponRequest.php
@@ -13,6 +13,9 @@ public function authorize(): bool
         return Gate::allows('apply', $this->getCoupon());
     }
 
+    /**
+     * @return array<string, string>
+     */
     public function rules(): array
     {
         return [
diff --git a/src/Http/Requests/CreateCouponRequest.php b/src/Http/Requests/CreateCouponRequest.php
index 8f50e7a..be4646c 100644
--- a/src/Http/Requests/CreateCouponRequest.php
+++ b/src/Http/Requests/CreateCouponRequest.php
@@ -19,6 +19,9 @@ public function authorize(): bool
         return Gate::allows('create', Coupon::class);
     }
 
+    /**
+     * @return array<string, array<int, mixed>>
+     */
     public function rules(): array
     {
         return [
@@ -47,7 +50,7 @@ public function rules(): array
         ];
     }
 
-    public function withValidator(Validator $validator)
+    public function withValidator(Validator $validator): void
     {
         $validator->sometimes('amount', 'max:100', function ($input) {
             return $input->type === CouponTypeEnum::CART_PERCENT ||  $input->type === CouponTypeEnum::PRODUCT_PERCENT;
diff --git a/src/Http/Requests/DeleteCouponRequest.php b/src/Http/Requests/DeleteCouponRequest.php
index b47da73..d4528dd 100644
--- a/src/Http/Requests/DeleteCouponRequest.php
+++ b/src/Http/Requests/DeleteCouponRequest.php
@@ -13,6 +13,9 @@ public function authorize(): bool
         return Gate::allows('delete', $this->getCoupon());
     }
 
+    /**
+     * @return array<string, array<int, mixed>>
+     */
     public function rules(): array
     {
         return [];
diff --git a/src/Http/Requests/ListCouponsRequest.php b/src/Http/Requests/ListCouponsRequest.php
index 99ed618..2dba3cb 100644
--- a/src/Http/Requests/ListCouponsRequest.php
+++ b/src/Http/Requests/ListCouponsRequest.php
@@ -17,6 +17,9 @@ public function authorize(): bool
         return Gate::allows('viewAny', Coupon::class);
     }
 
+    /**
+     * @return array<string, array<int, mixed>>
+     */
     public function rules(): array
     {
         return [
diff --git a/src/Http/Requests/ReadCouponRequest.php b/src/Http/Requests/ReadCouponRequest.php
index 4a18567..2ffd99d 100644
--- a/src/Http/Requests/ReadCouponRequest.php
+++ b/src/Http/Requests/ReadCouponRequest.php
@@ -13,6 +13,9 @@ public function authorize(): bool
         return Gate::allows('view', $this->getCoupon());
     }
 
+    /**
+     * @return array<string, array<int, mixed>>
+     */
     public function rules(): array
     {
         return [];
diff --git a/src/Http/Requests/UnapplyCouponRequest.php b/src/Http/Requests/UnapplyCouponRequest.php
index 7d2d747..a114369 100644
--- a/src/Http/Requests/UnapplyCouponRequest.php
+++ b/src/Http/Requests/UnapplyCouponRequest.php
@@ -13,6 +13,9 @@ public function authorize(): bool
         return Gate::allows('unapply', Coupon::class);
     }
 
+    /**
+     * @return array<string, array<int, mixed>>
+     */
     public function rules(): array
     {
         return [];
diff --git a/src/Http/Requests/UpdateCouponRequest.php b/src/Http/Requests/UpdateCouponRequest.php
index bd94920..21c2bf0 100644
--- a/src/Http/Requests/UpdateCouponRequest.php
+++ b/src/Http/Requests/UpdateCouponRequest.php
@@ -19,6 +19,9 @@ public function authorize(): bool
         return Gate::allows('update', $this->getCoupon());
     }
 
+    /**
+     * @return array<string, array<int, mixed>>
+     */
     public function rules(): array
     {
         return [
@@ -47,7 +50,7 @@ public function rules(): array
         ];
     }
 
-    public function withValidator(Validator $validator)
+    public function withValidator(Validator $validator): void
     {
         $validator->sometimes('amount', 'max:100', function ($input) {
             return $input->type === CouponTypeEnum::CART_PERCENT ||  $input->type === CouponTypeEnum::PRODUCT_PERCENT;
diff --git a/src/Http/Resources/CartItemResource.php b/src/Http/Resources/CartItemResource.php
index 3777315..4b67616 100644
--- a/src/Http/Resources/CartItemResource.php
+++ b/src/Http/Resources/CartItemResource.php
@@ -19,6 +19,10 @@ protected function getCartItem(): CartItem
         return $this->resource;
     }
 
+    /**
+     * @param $request
+     * @return array<string, mixed>
+     */
     public function toArray($request): array
     {
         return array_merge(parent::toArray($request), [
diff --git a/src/Http/Resources/CartResource.php b/src/Http/Resources/CartResource.php
index d6a04c5..51a08db 100644
--- a/src/Http/Resources/CartResource.php
+++ b/src/Http/Resources/CartResource.php
@@ -25,6 +25,10 @@ protected function getCartItemsResourceCollection(): ResourceCollection
         return CartItemResource::collection($this->getCart()->items);
     }
 
+    /**
+     * @param $request
+     * @return array<string, mixed>
+     */
     public function toArray($request): array
     {
         return array_merge(parent::toArray($request), [
diff --git a/src/Http/Resources/CouponProductResource.php b/src/Http/Resources/CouponProductResource.php
index eccac73..3a99e23 100644
--- a/src/Http/Resources/CouponProductResource.php
+++ b/src/Http/Resources/CouponProductResource.php
@@ -12,12 +12,16 @@ public function __construct(CouponProduct $couponProduct)
         parent::__construct($couponProduct);
     }
 
-    public function toArray($request)
+    /**
+     * @param $request
+     * @return array<string, mixed>
+     */
+    public function toArray($request): array
     {
         return [
-            'id' => $this->id,
-            'coupon_id' => $this->coupon_id,
-            'product_id' => $this->product_id,
+            'id' => $this->resource->id,
+            'coupon_id' => $this->resource->coupon_id,
+            'product_id' => $this->resource->product_id,
         ];
     }
 }
diff --git a/src/Http/Resources/CouponResource.php b/src/Http/Resources/CouponResource.php
index 8eed32a..cf5c65d 100644
--- a/src/Http/Resources/CouponResource.php
+++ b/src/Http/Resources/CouponResource.php
@@ -16,28 +16,32 @@ public function __construct(Coupon $coupon)
         parent::__construct($coupon);
     }
 
-    public function toArray($request)
+    /**
+     * @param $request
+     * @return array<string, mixed>
+     */
+    public function toArray($request): array
     {
         $couponService = app(CouponServiceContract::class);
         return [
-            'id' => $this->id,
-            'name' => $this->name,
-            'code' => $this->code,
-            'type' => $this->type,
-            'active' => $this->active,
-            'active_from' => $this->active_from,
-            'active_to' =>  $this->active_to,
-            'limit_usage' =>  $this->limit_usage,
-            'limit_per_user' =>  $this->limit_per_user,
-            'min_cart_price' => $this->min_cart_price,
-            'max_cart_price' =>  $this->max_cart_price,
-            'amount' =>  $this->amount,
-            'included_products' => ProductResource::collection($this->includedProducts),
-            'excluded_products' => ProductResource::collection($this->excludedProducts),
-            'users' => $this->users->map(fn (User $user) => $user->getKey())->toArray(),
-            'included_categories' => CategoryResource::collection($this->includedCategories),
-            'excluded_categories' => CategoryResource::collection($this->excludedCategories),
-            'exclude_promotions' => $this->exclude_promotions,
+            'id' => $this->resource->id,
+            'name' => $this->resource->name,
+            'code' => $this->resource->code,
+            'type' => $this->resource->type,
+            'active' => $this->resource->active,
+            'active_from' => $this->resource->active_from,
+            'active_to' => $this->resource->active_to,
+            'limit_usage' => $this->resource->limit_usage,
+            'limit_per_user' => $this->resource->limit_per_user,
+            'min_cart_price' => $this->resource->min_cart_price,
+            'max_cart_price' => $this->resource->max_cart_price,
+            'amount' => $this->resource->amount,
+            'included_products' => ProductResource::collection($this->resource->includedProducts),
+            'excluded_products' => ProductResource::collection($this->resource->excludedProducts),
+            'users' => $this->resource->users->map(fn (User $user) => $user->getKey())->toArray(),
+            'included_categories' => CategoryResource::collection($this->resource->includedCategories),
+            'excluded_categories' => CategoryResource::collection($this->resource->excludedCategories),
+            'exclude_promotions' => $this->resource->exclude_promotions,
             'usages' => $couponService->couponTimesUsed($this->resource),
         ];
     }
diff --git a/src/Models/Cart.php b/src/Models/Cart.php
index 86087f3..2efd9f5 100644
--- a/src/Models/Cart.php
+++ b/src/Models/Cart.php
@@ -40,13 +40,20 @@
  */
 class Cart extends BaseCart
 {
+    /** @var array<int, string> */
     protected $guarded = ['id', 'cartManager'];
 
+    /**
+     * @return BelongsTo<Coupon, self>
+     */
     public function coupon(): BelongsTo
     {
         return $this->belongsTo(Coupon::class);
     }
 
+    /**
+     * @return HasMany<CartItem>
+     */
     public function items(): HasMany
     {
         return $this->hasMany(CartItem::class);
diff --git a/src/Models/CartItem.php b/src/Models/CartItem.php
index b934fb4..a71d034 100644
--- a/src/Models/CartItem.php
+++ b/src/Models/CartItem.php
@@ -47,22 +47,25 @@
  */
 class CartItem extends BaseCartItem
 {
+    /**
+     * @return BelongsTo<Cart, self>
+     */
     public function cart(): BelongsTo
     {
         return $this->belongsTo(Cart::class);
     }
 
-    public function getSubtotalAttribute()
+    public function getSubtotalAttribute(): float
     {
         return parent::getSubtotalAttribute() - $this->discountSubtotal;
     }
 
-    public function getPriceAttribute()
+    public function getPriceAttribute(): float|null
     {
         return parent::getPriceAttribute() - $this->discount;
     }
 
-    public function getBasePriceAttribute()
+    public function getBasePriceAttribute(): float|null
     {
         return parent::getPriceAttribute();
     }
diff --git a/src/Models/Category.php b/src/Models/Category.php
index 732ca42..5e51547 100644
--- a/src/Models/Category.php
+++ b/src/Models/Category.php
@@ -47,12 +47,15 @@ class Category extends BaseCategory
 {
     use HasFactory;
 
+    /**
+     * @return BelongsToMany<Coupon>
+     */
     public function coupons(): BelongsToMany
     {
         return $this->belongsToMany(Coupon::class, 'coupons_categories', 'category_id', 'coupon_id')->using(CouponCategory::class);
     }
 
-    protected static function newFactory()
+    protected static function newFactory(): CategoryFactory
     {
         return new CategoryFactory();
     }
diff --git a/src/Models/Coupon.php b/src/Models/Coupon.php
index 7cd3057..6688a8d 100644
--- a/src/Models/Coupon.php
+++ b/src/Models/Coupon.php
@@ -2,6 +2,7 @@
 
 namespace EscolaLms\Vouchers\Models;
 
+use EscolaLms\Payments\Services\PaymentsService;
 use EscolaLms\Vouchers\Database\Factories\CouponFactory;
 use EscolaLms\Vouchers\Enums\CouponTypeEnum;
 use EscolaLms\Vouchers\Models\Product;
@@ -110,7 +111,7 @@
  *          @OA\Items(type="boolean")
  *      ),
  * )
- * 
+ *
  * @property int $id
  * @property string|null $name
  * @property string $code
@@ -126,6 +127,7 @@
  * @property \Illuminate\Support\Carbon|null $created_at
  * @property \Illuminate\Support\Carbon|null $updated_at
  * @property bool $exclude_promotions
+ * @property int $value
  * @property-read \Illuminate\Database\Eloquent\Collection|\EscolaLms\Vouchers\Models\Cart[] $carts
  * @property-read int|null $carts_count
  * @property-read \Illuminate\Database\Eloquent\Collection|\EscolaLms\Vouchers\Models\Category[] $categories
@@ -194,57 +196,84 @@ public function getValueStringAttribute(): string
         }
     }
 
+    /**
+     * @return BelongsToMany<User>
+     */
     public function users(): BelongsToMany
     {
         return $this->belongsToMany(User::class, 'coupon_user', 'coupon_id', 'user_id')->using(CouponUser::class);
     }
 
+    /**
+     * @return BelongsToMany<Product>
+     */
     public function products(): BelongsToMany
     {
         return $this->belongsToMany(Product::class, 'coupons_products', 'coupon_id', 'product_id')->using(CouponProduct::class);
     }
 
+    /**
+     * @return BelongsToMany<Product>
+     */
     public function includedProducts(): BelongsToMany
     {
         return $this->products()->wherePivot('excluded', false);
     }
 
+    /**
+     * @return BelongsToMany<Product>
+     */
     public function excludedProducts(): BelongsToMany
     {
         return $this->products()->wherePivot('excluded', true);
     }
 
+    /**
+     * @return BelongsToMany<Category>
+     */
     public function categories(): BelongsToMany
     {
         return $this->belongsToMany(Category::class, 'coupons_categories', 'coupon_id', 'category_id')->using(CouponCategory::class);
     }
 
+    /**
+     * @return BelongsToMany<Category>
+     */
     public function includedCategories(): BelongsToMany
     {
         return $this->categories()->wherePivot('excluded', false);
     }
 
+    /**
+     * @return BelongsToMany<Category>
+     */
     public function excludedCategories(): BelongsToMany
     {
         return $this->categories()->wherePivot('excluded', true);
     }
 
+    /**
+     * @return HasMany<Cart>
+     */
     public function carts(): HasMany
     {
         return $this->hasMany(Cart::class);
     }
 
+    /**
+     * @return HasMany<Order>
+     */
     public function orders(): HasMany
     {
         return $this->hasMany(Order::class);
     }
 
-    protected static function newFactory()
+    protected static function newFactory(): CouponFactory
     {
         return new CouponFactory();
     }
 
-    protected static function booted()
+    protected static function booted(): void
     {
         parent::booted();
         self::saving(function (Coupon $coupon) {
diff --git a/src/Models/CouponCategory.php b/src/Models/CouponCategory.php
index 4cb08b7..5029ec6 100644
--- a/src/Models/CouponCategory.php
+++ b/src/Models/CouponCategory.php
@@ -32,6 +32,9 @@ class CouponCategory extends Pivot
 {
     use HasTimestamps;
 
+    /**
+     * @var array<int, string>
+     */
     public $guarded = ['id'];
 
     protected $table = 'coupons_categories';
@@ -40,11 +43,17 @@ class CouponCategory extends Pivot
         'excluded' => 'bool'
     ];
 
+    /**
+     * @return BelongsTo<Coupon, self>
+     */
     public function coupon(): BelongsTo
     {
         return $this->belongsTo(Coupon::class);
     }
 
+    /**
+     * @return BelongsTo<Category, self>
+     */
     public function category(): BelongsTo
     {
         return $this->belongsTo(Category::class);
diff --git a/src/Models/CouponProduct.php b/src/Models/CouponProduct.php
index d254bff..e339a35 100644
--- a/src/Models/CouponProduct.php
+++ b/src/Models/CouponProduct.php
@@ -33,6 +33,9 @@ class CouponProduct extends Pivot
 {
     use HasTimestamps;
 
+    /**
+     * @var array<int, string>
+     */
     public $guarded = ['id'];
 
     protected $table = 'coupons_products';
@@ -41,11 +44,17 @@ class CouponProduct extends Pivot
         'excluded' => 'bool'
     ];
 
+    /**
+     * @return BelongsTo<Coupon, self>
+     */
     public function coupon(): BelongsTo
     {
         return $this->belongsTo(Coupon::class);
     }
 
+    /**
+     * @return BelongsTo<Product, self>
+     */
     public function product(): BelongsTo
     {
         return $this->belongsTo(Product::class);
diff --git a/src/Models/CouponUser.php b/src/Models/CouponUser.php
index 84e88c3..45c4281 100644
--- a/src/Models/CouponUser.php
+++ b/src/Models/CouponUser.php
@@ -27,13 +27,22 @@
  */
 class CouponUser extends Pivot
 {
+    /**
+     * @var array<int, string>
+     */
     public $guarded = ['id'];
 
+    /**
+     * @return BelongsTo<Coupon, self>
+     */
     public function coupon(): BelongsTo
     {
         return $this->belongsTo(Coupon::class);
     }
 
+    /**
+     * @return BelongsTo<User, self>
+     */
     public function user(): BelongsTo
     {
         return $this->belongsTo(User::class);
diff --git a/src/Models/Order.php b/src/Models/Order.php
index 4158d83..03e186b 100644
--- a/src/Models/Order.php
+++ b/src/Models/Order.php
@@ -63,6 +63,9 @@
  */
 class Order extends BaseOrder
 {
+    /**
+     * @return BelongsTo<Coupon, self>
+     */
     public function coupon(): BelongsTo
     {
         return $this->belongsTo(Coupon::class);
diff --git a/src/Models/OrderItem.php b/src/Models/OrderItem.php
index 81e578d..637ee6c 100644
--- a/src/Models/OrderItem.php
+++ b/src/Models/OrderItem.php
@@ -52,6 +52,9 @@
  */
 class OrderItem extends BaseOrderItem
 {
+    /**
+     * @return BelongsTo<Order, self>
+     */
     public function order(): BelongsTo
     {
         return $this->belongsTo(Order::class);
diff --git a/src/Models/Product.php b/src/Models/Product.php
index 3c7406c..479e16c 100644
--- a/src/Models/Product.php
+++ b/src/Models/Product.php
@@ -70,6 +70,9 @@
  */
 class Product extends BaseProduct
 {
+    /**
+     * @return BelongsToMany<Coupon>
+     */
     public function coupons(): BelongsToMany
     {
         return $this->belongsToMany(Coupon::class, 'coupons_products', 'product_id', 'coupon_id')->using(CouponProduct::class);
diff --git a/src/Models/User.php b/src/Models/User.php
index e11844f..4252ae1 100644
--- a/src/Models/User.php
+++ b/src/Models/User.php
@@ -80,21 +80,33 @@
  */
 class User extends CartUser
 {
+    /**
+     * @return HasMany<Order>
+     */
     public function orders(): HasMany
     {
         return $this->hasMany(Order::class, 'user_id');
     }
 
+    /**
+     * @return HasOne<Cart>
+     */
     public function cart(): HasOne
     {
         return $this->hasOne(Cart::class, 'user_id');
     }
 
+    /**
+     * @return BelongsToMany<Product>
+     */
     public function products(): BelongsToMany
     {
         return $this->belongsToMany(Product::class, 'products_users', 'user_id', 'product_id');
     }
 
+    /**
+     * @return BelongsToMany<Coupon>
+     */
     public function coupons(): BelongsToMany
     {
         return $this->belongsToMany(Coupon::class, 'coupon_user', 'user_id', 'coupon_id')->using(CouponUser::class);
diff --git a/src/Policies/CouponPolicy.php b/src/Policies/CouponPolicy.php
index c937d7c..b9d3521 100644
--- a/src/Policies/CouponPolicy.php
+++ b/src/Policies/CouponPolicy.php
@@ -19,37 +19,37 @@ public function __construct(CouponServiceContract $couponService)
         $this->couponService = $couponService;
     }
 
-    public function viewAny(User $user)
+    public function viewAny(User $user): bool
     {
         return $user->can(VoucherPermissionsEnum::COUPON_LIST);
     }
 
-    public function view(User $user, Coupon $course)
+    public function view(User $user, Coupon $course): bool
     {
         return $user->can(VoucherPermissionsEnum::COUPON_READ);
     }
 
-    public function create(User $user)
+    public function create(User $user): bool
     {
         return $user->can(VoucherPermissionsEnum::COUPON_CREATE);
     }
 
-    public function update(User $user, Coupon $coupon)
+    public function update(User $user, Coupon $coupon): bool
     {
         return $user->can(VoucherPermissionsEnum::COUPON_UPDATE);
     }
 
-    public function delete(User $user, Coupon $coupon)
+    public function delete(User $user, Coupon $coupon): bool
     {
         return $user->can(VoucherPermissionsEnum::COUPON_DELETE);
     }
 
-    public function apply(User $user, Coupon $coupon)
+    public function apply(User $user, Coupon $coupon): bool
     {
         return $user->can(VoucherPermissionsEnum::COUPON_USE);
     }
 
-    public function unapply(User $user)
+    public function unapply(User $user): bool
     {
         return $user->can(VoucherPermissionsEnum::COUPON_USE);
     }
diff --git a/src/Providers/AuthServiceProvider.php b/src/Providers/AuthServiceProvider.php
index 1ef8d2c..66812e3 100644
--- a/src/Providers/AuthServiceProvider.php
+++ b/src/Providers/AuthServiceProvider.php
@@ -12,7 +12,7 @@ class AuthServiceProvider extends ServiceProvider
     /**
      * The policy mappings for the application.
      *
-     * @var array
+     * @var array<class-string, class-string>
      */
     protected $policies = [
         Coupon::class => CouponPolicy::class,
@@ -23,7 +23,7 @@ class AuthServiceProvider extends ServiceProvider
      *
      * @return void
      */
-    public function boot()
+    public function boot(): void
     {
         $this->registerPolicies();
 
diff --git a/src/Services/CartManager.php b/src/Services/CartManager.php
index 904b8d6..6a53661 100644
--- a/src/Services/CartManager.php
+++ b/src/Services/CartManager.php
@@ -49,6 +49,7 @@ public function discountForItem(CartItem $item): int
     public function removeCoupon(): self
     {
         $this->cart->refresh();
+        // @phpstan-ignore-next-line
         $this->cart->coupon_id = null;
         $this->cart->save();
         $this->cart->refresh();
@@ -57,6 +58,7 @@ public function removeCoupon(): self
 
     public function setCoupon(?Coupon $coupon): self
     {
+        // @phpstan-ignore-next-line
         if (!is_null($coupon) && !app(CouponServiceContract::class)->couponCanBeUsedOnCart($coupon, $this->cart)) {
             if (!app(CouponServiceContract::class)->couponIsActive($coupon)) {
                 throw new CouponInactiveException();
@@ -65,6 +67,7 @@ public function setCoupon(?Coupon $coupon): self
         }
 
         $this->cart->refresh();
+        // @phpstan-ignore-next-line
         $this->cart->coupon_id = $coupon->getKey();
         $this->cart->save();
         $this->cart->refresh();
diff --git a/src/Services/Contracts/CouponServiceContract.php b/src/Services/Contracts/CouponServiceContract.php
index 65f1754..8fa11c0 100644
--- a/src/Services/Contracts/CouponServiceContract.php
+++ b/src/Services/Contracts/CouponServiceContract.php
@@ -15,11 +15,23 @@
 
 interface CouponServiceContract
 {
+    /**
+     * @return LengthAwarePaginator<Coupon>
+     */
     public function searchAndPaginateCoupons(CouponSearchDto $searchDto, ?OrderDto $orderDto = null): LengthAwarePaginator;
 
     public function getDiscountStrategyForCoupon(?Coupon $coupon): DiscountStrategyContract;
 
+    /**
+     * @param array<string, mixed> $data
+     */
     public function createCoupon(array $data): Coupon;
+
+    /**
+     * @param Coupon $coupon
+     * @param array<string, mixed> $data
+     * @return Coupon
+     */
     public function updateCoupon(Coupon $coupon, array $data): Coupon;
 
     public function couponCanBeUsedOnCart(Coupon $coupon, Cart $cart): bool;
@@ -27,12 +39,24 @@ public function couponIsActive(Coupon $coupon): bool;
     public function couponInPriceRange(Coupon $coupon, int $price): bool;
 
     public function cartContainsItemsIncludedInCoupon(Coupon $coupon, Cart $cart): bool;
+
+    /**
+     * @param Coupon $coupon
+     * @param Cart $cart
+     * @return Collection<int, \Treestoneit\ShoppingCart\Models\CartItem|CartItem>
+     */
     public function cartItemsIncludedInCoupon(Coupon $coupon, Cart $cart): Collection;
     public function cartItemIsIncludedInCoupon(Coupon $coupon, CartItem $item): bool;
     public function productIsIncludedInCoupon(Coupon $coupon, Product $product): bool;
     public function productCategoriesAreIncludedInCoupon(Coupon $coupon, Product $product): bool;
 
     public function cartContainsItemsNotExcludedFromCoupon(Coupon $coupon, Cart $cart): bool;
+
+    /**
+     * @param Coupon $coupon
+     * @param Cart $cart
+     * @return Collection<int, \Treestoneit\ShoppingCart\Models\CartItem|CartItem>
+     */
     public function cartItemsWithoutExcludedFromCoupon(Coupon $coupon, Cart $cart): Collection;
     public function cartItemIsExcludedFromCoupon(Coupon $coupon, CartItem $item): bool;
     public function productIsExcludedFromCoupon(Coupon $coupon, Product $product): bool;
diff --git a/src/Services/CouponService.php b/src/Services/CouponService.php
index c96cc6d..c67828b 100644
--- a/src/Services/CouponService.php
+++ b/src/Services/CouponService.php
@@ -26,6 +26,11 @@
 
 class CouponService implements CouponServiceContract
 {
+    /**
+     * @param CouponSearchDto $searchDto
+     * @param OrderDto|null $orderDto
+     * @return LengthAwarePaginator<Coupon>
+     */
     public function searchAndPaginateCoupons(CouponSearchDto $searchDto, ?OrderDto $orderDto = null): LengthAwarePaginator
     {
         $query = Coupon::query();
@@ -67,6 +72,10 @@ public function searchAndPaginateCoupons(CouponSearchDto $searchDto, ?OrderDto $
         return $query->paginate($searchDto->getPerPage() ?? 15);
     }
 
+    /**
+     * @param array<string, mixed> $data
+     * @return Coupon
+     */
     public function createCoupon(array $data): Coupon
     {
         $coupon = new Coupon([
@@ -124,6 +133,11 @@ public function createCoupon(array $data): Coupon
         return $coupon->refresh();
     }
 
+    /**
+     * @param Coupon $coupon
+     * @param array<string, mixed> $data
+     * @return Coupon
+     */
     public function updateCoupon(Coupon $coupon, array $data): Coupon
     {
         if (!isset($data['included_products'])) {
@@ -230,9 +244,17 @@ public function cartContainsItemsIncludedInCoupon(Coupon $coupon, Cart $cart): b
         return ($coupon->includedProducts()->count() === 0 && $coupon->includedCategories()->count() === 0) || $this->cartItemsIncludedInCoupon($coupon, $cart)->count() > 0;
     }
 
+    /**
+     * @param Coupon $coupon
+     * @param Cart $cart
+     * @return Collection<int, CartItem|\EscolaLms\Vouchers\Models\CartItem>
+     */
     public function cartItemsIncludedInCoupon(Coupon $coupon, Cart $cart): Collection
     {
-        return $cart->items->filter(fn (CartItem $item) => $this->cartItemIsIncludedInCoupon($coupon, $item));
+        /** @var Collection<int, CartItem|\EscolaLms\Vouchers\Models\CartItem> $items */
+        // @phpstan-ignore-next-line
+        $items = $cart->items->filter(fn (CartItem $item) => $this->cartItemIsIncludedInCoupon($coupon, $item));
+        return $items;
     }
 
     public function cartItemIsIncludedInCoupon(Coupon $coupon, CartItem $item): bool
@@ -255,9 +277,17 @@ public function cartContainsItemsNotExcludedFromCoupon(Coupon $coupon, Cart $car
         return ($coupon->excludedProducts()->count() === 0 && $coupon->excludedCategories()->count() === 0) || $this->cartItemsWithoutExcludedFromCoupon($coupon, $cart)->count() > 0;
     }
 
+    /**
+     * @param Coupon $coupon
+     * @param Cart $cart
+     * @return Collection<int, CartItem|\EscolaLms\Vouchers\Models\CartItem>
+     */
     public function cartItemsWithoutExcludedFromCoupon(Coupon $coupon, Cart $cart): Collection
     {
-        return $cart->items->filter(fn (CartItem $item) => !$this->cartItemIsExcludedFromCoupon($coupon, $item));
+        /** @var Collection<int, CartItem|\EscolaLms\Vouchers\Models\CartItem> $result */
+        // @phpstan-ignore-next-line
+        $result = $cart->items->filter(fn (CartItem $item) => !$this->cartItemIsExcludedFromCoupon($coupon, $item));
+        return $result;
     }
 
     public function cartItemIsExcludedFromCoupon(Coupon $coupon, CartItem $item): bool
@@ -267,6 +297,7 @@ public function cartItemIsExcludedFromCoupon(Coupon $coupon, CartItem $item): bo
 
     public function cartFulfilPromotionConditions(Coupon $coupon, Cart $cart): bool
     {
+        // @phpstan-ignore-next-line
         return !$coupon->exclude_promotions || $cart->items->filter(fn (CartItem $item) => $this->productOnPromotion($coupon, $item))->count() === 0;
     }
 
diff --git a/src/Services/OrderService.php b/src/Services/OrderService.php
index e0c0558..d7b4f83 100644
--- a/src/Services/OrderService.php
+++ b/src/Services/OrderService.php
@@ -15,9 +15,12 @@
 class OrderService extends BaseOrderService implements OrderServiceContract
 {
     /** @return Order */
+    // @phpstan-ignore-next-line
     public function find($id): Model
     {
-        return Order::findOrFail($id);
+        /** @var Order $order */
+        $order = Order::findOrFail($id);
+        return $order;
     }
 
     public function createOrderFromCart(BaseCart $cart, ?ClientDetailsDto $clientDetailsDto = null): Order
@@ -28,9 +31,11 @@ public function createOrderFromCart(BaseCart $cart, ?ClientDetailsDto $clientDet
     public function createOrderFromCartManager(BaseCartManager $cartManager, ?ClientDetailsDto $clientDetailsDto = null): Order
     {
         if (!$cartManager instanceof CartManager) {
+            // @phpstan-ignore-next-line
             $cartManager = new CartManager($cartManager->getModel());
         }
         $order = parent::createOrderFromCartManager($cartManager, $clientDetailsDto);
+        /** @var Order $order */
         $order = $order instanceof Order ? $order : Order::find($order->getKey());
         $order->coupon_id = optional($cartManager->getCoupon())->getKey();
         $order->discount = $cartManager->additionalDiscount();
diff --git a/src/Strategies/CartFixedDiscountStrategy.php b/src/Strategies/CartFixedDiscountStrategy.php
index b19b02a..d575d0b 100644
--- a/src/Strategies/CartFixedDiscountStrategy.php
+++ b/src/Strategies/CartFixedDiscountStrategy.php
@@ -37,7 +37,7 @@ public function calculateDiscountForItem(Cart $cart, CartItem $cartItem): int
             $tax = (1 + $cartItem->tax_rate / 100);
             $itemValue = $cartItem->basePrice * $tax;
             $discount = round($itemValue / $totalAmount * $maxAmount, 0);
-            return round($discount / $tax, 0);
+            return (int) round($discount / $tax, 0);
         }
 
         return 0;
diff --git a/src/Strategies/CartPercentDiscountStrategy.php b/src/Strategies/CartPercentDiscountStrategy.php
index edf35e9..f63038f 100644
--- a/src/Strategies/CartPercentDiscountStrategy.php
+++ b/src/Strategies/CartPercentDiscountStrategy.php
@@ -20,6 +20,7 @@ public function calculateDiscountForItem(Cart $cart, CartItem $cartItem): int
         if (app(CouponServiceContract::class)->cartItemIsExcludedFromCoupon($this->coupon, $cartItem)) {
             return 0;
         }
-        return round($this->coupon->amount * $cartItem->buyable->getBuyablePrice() / 100, 0);
+        // @phpstan-ignore-next-line
+        return (int) round($this->coupon->amount * $cartItem->buyable->getBuyablePrice() / 100, 0);
     }
 }
diff --git a/src/Strategies/ProductFixedDiscountStrategy.php b/src/Strategies/ProductFixedDiscountStrategy.php
index 5f8637b..34d107e 100644
--- a/src/Strategies/ProductFixedDiscountStrategy.php
+++ b/src/Strategies/ProductFixedDiscountStrategy.php
@@ -24,8 +24,8 @@ public function calculateDiscountForItem(Cart $cart, CartItem $cartItem): int
         $itemValue = $cartItem->basePrice * $tax;
         $discount = $itemValue < $this->coupon->amount ? $itemValue : $this->coupon->amount;
         if ($discount === $itemValue) {
-            return $cartItem->basePrice;
+            return (int) $cartItem->basePrice;
         }
-        return round($discount / $tax, 0);
+        return (int) round($discount / $tax, 0);
     }
 }
diff --git a/src/Strategies/ProductPercentDiscountStrategy.php b/src/Strategies/ProductPercentDiscountStrategy.php
index 2d4ffc4..7ec9d8b 100644
--- a/src/Strategies/ProductPercentDiscountStrategy.php
+++ b/src/Strategies/ProductPercentDiscountStrategy.php
@@ -20,6 +20,7 @@ public function calculateDiscountForItem(Cart $cart, CartItem $cartItem): int
         if (!app(CouponServiceContract::class)->cartItemIsIncludedInCoupon($this->coupon, $cartItem)) {
             return 0;
         }
-        return round($this->coupon->amount * $cartItem->buyable->getBuyablePrice() / 100, 0);
+        // @phpstan-ignore-next-line
+        return (int) round($this->coupon->amount * $cartItem->buyable->getBuyablePrice() / 100, 0);
     }
 }