diff --git a/domain-model.md b/domain-model.md
new file mode 100644
index 0000000..290ef9a
--- /dev/null
+++ b/domain-model.md
@@ -0,0 +1,21 @@
+| Classes        | Variables                           | Methods                               | Scenario              | Outcomes             |
+|----------------|-------------------------------------|---------------------------------------|-----------------------|----------------------|
+| `CashRegister` | `Map<Integer, Integer> weightItem`  | `getPriceForWeightItem(int PLUCode)`  | Product is in map     | Add price to total   |
+|                | `Map<barcode, Integer> barcodeItem` | `getPriceForBarcodeItem(int barcode)` | Product is not in map | Return error message |
+|                |                                     |                                       |                       |                      |
+|                | `ìnt totalCost`                     | `getTotalCost()`                      | Total cost is > 0     | Return total cost    |
+|                |                                     |                                       | Total cost is < 0     | Return error message |
+|                |                                     |                                       |                       |                      |
+|                |                                     | `addToTotalCost(int price)`           | Price is > 0          | Add to totalCost     |
+|                |                                     |                                       | Price is < 0          | Return               |
+
+| Classes       | Variables                                                   | Methods                                 | Scenario                 | Outcomes                 |
+|---------------|-------------------------------------------------------------|-----------------------------------------|--------------------------|--------------------------|
+| `MembersDesk` | `Map<Integer, Map<Integer, List<Receipt>>> shoppingHistory` | `getShoppingHistory(int membersNumber)` | Customer is a member     | Return list of purchases |
+|               |                                                             |                                         | Customer is not a member | Return error message     |
+|               |                                                             |                                         |                          |                          |
+|               |                                                             | `getItemisedReceipt(int receiptNumber)` | Valid receipt number     | Return receipt           |
+|               |                                                             |                                         | In valid receipt number  | Return error message     |
+|               |                                                             |                                         |                          |                          |
+
+
diff --git a/src/main/java/com/booleanuk/core/Basket.java b/src/main/java/com/booleanuk/core/Basket.java
new file mode 100644
index 0000000..20c7a7d
--- /dev/null
+++ b/src/main/java/com/booleanuk/core/Basket.java
@@ -0,0 +1,24 @@
+package com.booleanuk.core;
+
+import java.util.HashMap;
+
+public class Basket {
+    private final HashMap<String, Integer> items = new HashMap<>();
+
+    public boolean add(String product, int price) {
+        if (product.isEmpty() || items.containsKey(product)) {
+            return false;
+        }
+        items.put(product, price);
+        return true;
+    }
+
+    public int total() {
+        int total = 0;
+
+        for (int price : items.values()) {
+            total += price;
+        }
+        return total;
+    }
+}
\ No newline at end of file
diff --git a/src/test/java/com/booleanuk/core/BasketTest.java b/src/test/java/com/booleanuk/core/BasketTest.java
new file mode 100644
index 0000000..e8289ae
--- /dev/null
+++ b/src/test/java/com/booleanuk/core/BasketTest.java
@@ -0,0 +1,38 @@
+package com.booleanuk.core;
+
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.Test;
+
+public class BasketTest {
+
+    Basket basket = new Basket();
+
+    @Test
+    public void addMethodExistTest() {
+        Assertions.assertFalse(basket.add("", 0));
+    }
+
+    @Test
+    public void addItemTest() {
+        Assertions.assertFalse(basket.add("", 0));
+        Assertions.assertTrue(basket.add("Milk", 5));
+        Assertions.assertFalse(basket.add("Milk", 5));
+        Assertions.assertTrue(basket.add("Bread", 2));
+        Assertions.assertTrue(basket.add("Eggs", 3));
+    }
+
+    @Test
+    public void totalTest() {
+        Assertions.assertTrue(basket.add("Milk", 5));
+        Assertions.assertTrue(basket.add("Bread", 2));
+        Assertions.assertTrue(basket.add("Eggs", 3));
+        Assertions.assertNotEquals(0, basket.total());
+        Assertions.assertEquals(10, basket.total());
+
+        Assertions.assertTrue(basket.add("Apple", 5));
+        Assertions.assertEquals(15, basket.total());
+
+    }
+
+
+}