diff --git a/data/crud.go b/data/crud.go
index f0a5b3c..d8eb762 100644
--- a/data/crud.go
+++ b/data/crud.go
@@ -28,6 +28,7 @@ func Shutdown() {
 }
 
 func SelectJson[T any](c *fiber.Ctx, err error, sql string, args ...interface{}) error {
+  // BUG: add a precondition that aborts if array of interfaces to avoid "unsupported $1 array of interfaces"
   var result []T
   if err != nil { goto fail }
 
diff --git a/data/models.go b/data/models.go
index 2c59352..88c491d 100644
--- a/data/models.go
+++ b/data/models.go
@@ -25,9 +25,30 @@ type NullExample struct {
   HasMaybe null.Int `db:"replying_to" validate:"omitempty,numeric"`
 }
 
+type Product struct {
+  Id int `db:"id" validate:"numeric"`
+  Title string `db:"title" validate:"required"`
+  Description string `db:"description" validate:"required"`
+  Price float64 `db:"price" validate:"required"`
+  Slug string `db:"slug" validate:"required"`
+}
+
+type CartItem struct {
+  Id int `db:"id" validate:"numeric"`
+  UserId int `db:"user_id" validate:"numeric,required"`
+  ProductId int `db:"product_id" validate:"required"`
+  Quantity int `db:"quantity" validate:"numeric"`
+}
+
+type Cart struct {
+  Items []CartItem
+}
+
 func Models() map[string]reflect.Type {
   return map[string]reflect.Type{
     "user": reflect.TypeFor[User](),
+    "product": reflect.TypeFor[Product](),
+    "cart_item": reflect.TypeFor[CartItem](),
     "null_example": reflect.TypeFor[NullExample](),
   }
 }
diff --git a/features/init.go b/features/init.go
index 16e7c88..08322d3 100644
--- a/features/init.go
+++ b/features/init.go
@@ -2,11 +2,13 @@ package features
 
 import (
   "github.com/gofiber/fiber/v2"
-  email "MY/webapp/features/email"
-  paypal "MY/webapp/features/paypal"
+  "MY/webapp/features/email"
+  "MY/webapp/features/paypal"
+  "MY/webapp/features/shopping"
 )
 
 func Setup(app *fiber.App) {
-  email.Setup(app)
-  paypal.Setup(app)
+  features_email.Setup(app)
+  features_paypal.Setup(app)
+  features_shopping.Setup(app)
 }
diff --git a/migrations/20260112190943_shopping_init.sql b/migrations/20260112190943_shopping_init.sql
new file mode 100644
index 0000000..07fa190
--- /dev/null
+++ b/migrations/20260112190943_shopping_init.sql
@@ -0,0 +1,13 @@
+-- +goose Up
+-- +goose StatementBegin
+CREATE TABLE Product (id INTEGER PRIMARY KEY,
+  title TEXT,
+  description TEXT,
+  price float,
+  slug TEXT UNIQUE);
+-- +goose StatementEnd
+
+-- +goose Down
+-- +goose StatementBegin
+DROP TABLE Product;
+-- +goose StatementEnd
diff --git a/migrations/20260112195518_shopping_cart.sql b/migrations/20260112195518_shopping_cart.sql
new file mode 100644
index 0000000..9bd2802
--- /dev/null
+++ b/migrations/20260112195518_shopping_cart.sql
@@ -0,0 +1,13 @@
+-- +goose Up
+-- +goose StatementBegin
+CREATE TABLE Cart (
+  id INTEGER PRIMARY KEY,
+  user_id INTEGER NOT NULL,
+  product_id INTEGER NOT NULL,
+  quantity INTEGER);
+-- +goose StatementEnd
+
+-- +goose Down
+-- +goose StatementBegin
+DROP TABLE Cart;
+-- +goose StatementEnd