diff --git a/swap_meet/clothing.py b/swap_meet/clothing.py
index b8afdeb1e..fc518059e 100644
--- a/swap_meet/clothing.py
+++ b/swap_meet/clothing.py
@@ -1,2 +1,10 @@
-class Clothing:
-    pass
\ No newline at end of file
+from swap_meet.item import Item
+
+class Clothing(Item):
+    def __init__(self, category="", condition=0):
+        super().__init__("Clothing", condition)
+
+    def __str__(self):
+        return "The finest clothing you could wear."
+
+    
\ No newline at end of file
diff --git a/swap_meet/decor.py b/swap_meet/decor.py
index eab7a9dbe..2e8716d17 100644
--- a/swap_meet/decor.py
+++ b/swap_meet/decor.py
@@ -1,2 +1,10 @@
-class Decor:
-    pass
\ No newline at end of file
+from swap_meet.item import Item
+
+class Decor(Item):
+    def __init__(self, category="", condition=0):
+        super().__init__("Decor", condition)
+
+    def __str__(self):
+        return "Something to decorate your space."
+
+    
\ No newline at end of file
diff --git a/swap_meet/electronics.py b/swap_meet/electronics.py
index 2f9dff68a..f27959571 100644
--- a/swap_meet/electronics.py
+++ b/swap_meet/electronics.py
@@ -1,2 +1,12 @@
-class Electronics:
-    pass
+from swap_meet.item import Item
+
+class Electronics(Item):
+
+    def __init__(self, category="", condition=0):
+        super().__init__("Electronics", condition)
+    
+    def __str__(self):
+        return "A gadget full of buttons and secrets."
+
+    
+    
diff --git a/swap_meet/item.py b/swap_meet/item.py
index 560d759c2..8dd7944b6 100644
--- a/swap_meet/item.py
+++ b/swap_meet/item.py
@@ -1,2 +1,21 @@
+
 class Item:
-    pass
\ No newline at end of file
+    def __init__(self, category="", condition=0, age= float("inf")):
+        self.category = category
+        self.condition = condition 
+        self.age = age
+
+
+    def __str__(self):
+        return "Hello World!"
+    
+    def condition_description(self):
+        CONDITIONS = {
+            0: "Mint",
+            1: "Okay",
+            2: "Good",
+            3: "Great",
+            4: "Excellent",
+            5: "Flawless"
+        }
+        return CONDITIONS[self.condition]
\ No newline at end of file
diff --git a/swap_meet/vendor.py b/swap_meet/vendor.py
index 87302c056..5d09d6146 100644
--- a/swap_meet/vendor.py
+++ b/swap_meet/vendor.py
@@ -1,2 +1,97 @@
+from operator import attrgetter
+
 class Vendor:
-    pass
\ No newline at end of file
+    def __init__(self, inventory=None):
+        if inventory == None:
+            inventory = []
+        self.inventory = inventory
+
+    def add(self, item):
+        # Add item to the inventory
+        self.inventory.append(item)
+        # Return item that was added to inventory
+        return item
+        
+
+    def remove(self, item):
+        # Check if item in inventory that are match
+        if item in self.inventory:
+            # Remove item from the inventory
+            self.inventory.remove(item)
+            return item
+        return False # If no matching items
+
+    def get_by_category(self, category):
+        # Return a list of item inventory from that category
+        return [item for item in self.inventory if item.category == category]
+
+    def swap_items(self, other, my_item, their_item):
+
+        # Check if Vendor items not in her inventory or Vendor friend's item not in their inventory
+        if not my_item in self.inventory or not their_item in other.inventory:
+            return False
+        
+        # Vendor(my_item) add friend items to her inventory
+        self.inventory.append(their_item)
+        # Vendor remove her own items from her inventory
+        self.inventory.remove(my_item)
+        # Vendor friend's add Vendor to their inventory
+        other.inventory.append(my_item)
+        # Vendor friend's remove their item from their inventory
+        other.inventory.remove(their_item)
+
+        return True # Return True when Vendor and Vendor friend's swaping items from each other inventory
+
+    def swap_first_item(self, other):
+        # Check if Vendor and Vendor friend's inventory is not empty
+        if self.inventory and other.inventory:
+            # using index to access first item from vendor inventory
+            my_item = self.inventory[0]
+            #using index to access first item from vendor friend's inventory
+            their_item = other.inventory[0]
+            # using helper function, to swap first item from vendor and vendor friend's inventory
+            self.swap_items(other, my_item, their_item)
+
+            return True
+
+        return False # If empty list return False
+
+    def get_best_by_category(self, category):
+        # Check if there is no items in the inventory that match category
+        if not self.get_by_category(category):
+            return None
+        # Return the item that are match category and highest condition even there's duplicate items
+        return max(self.get_by_category(category), key=attrgetter("condition"))
+
+    def swap_best_by_category(self, other, my_priority, their_priority):
+        # Find the best items in Vendor inventory to match their priority
+        my_best_item = self.get_best_by_category(their_priority) 
+        # Find the best items in Vendor friend's to match Vendor priority
+        their_best_item = other.get_best_by_category(my_priority)
+        
+        # Return swap best items between Vendor and Vendor friend's from inventory
+        return self.swap_items(other, my_best_item, their_best_item)
+        
+    
+    def get_by_newest(self):
+        # Set minimum ages to float infinity
+        new_ages = float("inf")
+        # Set minimum items to None list
+        items = [None]
+        # Iterate item in the inventory
+        for item in self.inventory:
+            # Check if the item age is less than the new ages
+            if item.age < new_ages:
+                # update the item age 
+                items[0], new_ages = item, item.age
+            else:
+                # if item age equal to new age
+                if item.age == new_ages:
+                    # Add item to items list
+                    items.append(item)
+        return items
+    
+    
+
+    
+
diff --git a/tests/integration_tests/test_wave_01_02_03.py b/tests/integration_tests/test_wave_01_02_03.py
index 9912414da..f627caeb1 100644
--- a/tests/integration_tests/test_wave_01_02_03.py
+++ b/tests/integration_tests/test_wave_01_02_03.py
@@ -2,8 +2,8 @@
 from swap_meet.vendor import Vendor
 from swap_meet.item import Item
 
-@pytest.mark.skip
-@pytest.mark.integration_test
+#@pytest.mark.skip
+#@pytest.mark.integration_test
 def test_integration_wave_01_02_03():
     # make a vendor  
     vendor = Vendor()
diff --git a/tests/integration_tests/test_wave_04_05_06.py b/tests/integration_tests/test_wave_04_05_06.py
index 4d0be9909..5c875978b 100644
--- a/tests/integration_tests/test_wave_04_05_06.py
+++ b/tests/integration_tests/test_wave_04_05_06.py
@@ -4,8 +4,8 @@
 from swap_meet.decor import Decor
 from swap_meet.electronics import Electronics
 
-@pytest.mark.skip
-@pytest.mark.integration_test
+#@pytest.mark.skip
+#@pytest.mark.integration_test
 def test_integration_wave_04_05_06():
     camila = Vendor()
     valentina = Vendor()
diff --git a/tests/unit_tests/test_optional.py b/tests/unit_tests/test_optional.py
new file mode 100644
index 000000000..64461bec1
--- /dev/null
+++ b/tests/unit_tests/test_optional.py
@@ -0,0 +1,21 @@
+import pytest
+from swap_meet.vendor import Vendor
+from swap_meet.item import Item
+
+def test_item_by_age():
+    
+    age_1 = Item(age=5)
+    age_2 = Item(age=22)
+    age_3 = Item(age=30)
+    vendor = Vendor([age_1, age_2, age_3]
+    )
+    
+    age_items = vendor.get_by_newest()
+
+    assert age_items != age_1
+    assert age_items != age_2
+    assert age_items != age_3
+
+
+    
+
diff --git a/tests/unit_tests/test_wave_01.py b/tests/unit_tests/test_wave_01.py
index 58478ccf9..548c962f8 100644
--- a/tests/unit_tests/test_wave_01.py
+++ b/tests/unit_tests/test_wave_01.py
@@ -2,12 +2,12 @@
 import pytest
 from swap_meet.vendor import Vendor
 
-@pytest.mark.skip
+#@pytest.mark.skip
 def test_vendor_has_inventory():
     vendor = Vendor()
     assert len(vendor.inventory) == 0
 
-@pytest.mark.skip
+#@pytest.mark.skip
 def test_vendor_takes_optional_inventory():
     inventory = ["a", "b", "c"]
     vendor = Vendor(inventory=inventory)
@@ -16,7 +16,7 @@ def test_vendor_takes_optional_inventory():
     assert "b" in vendor.inventory
     assert "c" in vendor.inventory
 
-@pytest.mark.skip
+#@pytest.mark.skip
 def test_adding_to_inventory():
     vendor = Vendor()
     item = "new item"
@@ -27,7 +27,7 @@ def test_adding_to_inventory():
     assert item in vendor.inventory
     assert result == item
 
-@pytest.mark.skip
+#@pytest.mark.skip
 def test_removing_from_inventory_returns_item():
     item = "item to remove"
     vendor = Vendor(
@@ -40,7 +40,7 @@ def test_removing_from_inventory_returns_item():
     assert item not in vendor.inventory
     assert result == item
 
-@pytest.mark.skip
+#@pytest.mark.skip
 def test_removing_not_found_is_false():
     item = "item to remove"
     vendor = Vendor(
@@ -49,7 +49,10 @@ def test_removing_not_found_is_false():
 
     result = vendor.remove(item)
 
-    raise Exception("Complete this test according to comments below.")
+    #raise Exception("Complete this test according to comments below.")
+    assert result != item
+    assert item not in vendor.inventory
+    assert len(vendor.inventory) == 3
     # *********************************************************************
     # ****** Complete Assert Portion of this test **********
     # *********************************************************************
diff --git a/tests/unit_tests/test_wave_02.py b/tests/unit_tests/test_wave_02.py
index 3d7060d7c..20b6b7b3b 100644
--- a/tests/unit_tests/test_wave_02.py
+++ b/tests/unit_tests/test_wave_02.py
@@ -2,12 +2,12 @@
 from swap_meet.vendor import Vendor
 from swap_meet.item import Item
 
-@pytest.mark.skip
+#@pytest.mark.skip
 def test_items_have_blank_default_category():
     item = Item()
     assert item.category == ""
 
-@pytest.mark.skip
+#@pytest.mark.skip
 def test_get_items_by_category():
     item_a = Item(category="clothing")
     item_b = Item(category="electronics")
@@ -23,7 +23,7 @@ def test_get_items_by_category():
     assert item_c in items
     assert item_b not in items
 
-@pytest.mark.skip
+#@pytest.mark.skip
 def test_get_no_matching_items_by_category():
     item_a = Item(category="clothing")
     item_b = Item(category="clothing")
@@ -34,7 +34,11 @@ def test_get_no_matching_items_by_category():
 
     items = vendor.get_by_category("electronics")
 
-    raise Exception("Complete this test according to comments below.")
+    #raise Exception("Complete this test according to comments below.")
+    assert item_a != items
+    assert item_b != items
+    assert item_c != items
+
     # *********************************************************************
     # ****** Complete Assert Portion of this test **********
     # *********************************************************************
diff --git a/tests/unit_tests/test_wave_03.py b/tests/unit_tests/test_wave_03.py
index 0300b638f..720879a7c 100644
--- a/tests/unit_tests/test_wave_03.py
+++ b/tests/unit_tests/test_wave_03.py
@@ -2,7 +2,7 @@
 from swap_meet.vendor import Vendor
 from swap_meet.item import Item
 
-@pytest.mark.skip
+#@pytest.mark.skip
 def test_item_overrides_to_string():
     item = Item()
 
@@ -10,7 +10,7 @@ def test_item_overrides_to_string():
 
     assert stringified_item == "Hello World!"
 
-@pytest.mark.skip
+#@pytest.mark.skip
 def test_swap_items_returns_true():
     item_a = Item(category="clothing")
     item_b = Item(category="clothing")
@@ -38,7 +38,7 @@ def test_swap_items_returns_true():
     assert item_b in jolie.inventory
     assert result
 
-@pytest.mark.skip
+#@pytest.mark.skip
 def test_swap_items_when_my_item_is_missing_returns_false():
     item_a = Item(category="clothing")
     item_b = Item(category="clothing")
@@ -65,7 +65,7 @@ def test_swap_items_when_my_item_is_missing_returns_false():
     assert item_e in jolie.inventory
     assert not result
 
-@pytest.mark.skip
+#@pytest.mark.skip
 def test_swap_items_when_their_item_is_missing_returns_false():
     item_a = Item(category="clothing")
     item_b = Item(category="clothing")
@@ -92,7 +92,7 @@ def test_swap_items_when_their_item_is_missing_returns_false():
     assert item_e in jolie.inventory
     assert not result
 
-@pytest.mark.skip
+#@pytest.mark.skip
 def test_swap_items_from_my_empty_returns_false():
     fatimah = Vendor(
         inventory=[]
@@ -112,7 +112,7 @@ def test_swap_items_from_my_empty_returns_false():
     assert len(jolie.inventory) == 2
     assert not result
 
-@pytest.mark.skip
+#@pytest.mark.skip
 def test_swap_items_from_their_empty_returns_false():
     item_a = Item(category="clothing")
     item_b = Item(category="clothing")
diff --git a/tests/unit_tests/test_wave_04.py b/tests/unit_tests/test_wave_04.py
index 8190a4ebb..f3c91e846 100644
--- a/tests/unit_tests/test_wave_04.py
+++ b/tests/unit_tests/test_wave_04.py
@@ -2,7 +2,7 @@
 from swap_meet.vendor import Vendor
 from swap_meet.item import Item
 
-@pytest.mark.skip
+#@pytest.mark.skip
 def test_swap_first_item_returns_true():
     item_a = Item(category="clothing")
     item_b = Item(category="clothing")
@@ -30,7 +30,7 @@ def test_swap_first_item_returns_true():
     assert item_a in jolie.inventory
     assert result
 
-@pytest.mark.skip
+#@pytest.mark.skip
 def test_swap_first_item_from_my_empty_returns_false():
     fatimah = Vendor(
         inventory=[]
@@ -48,7 +48,7 @@ def test_swap_first_item_from_my_empty_returns_false():
     assert len(jolie.inventory) == 2
     assert not result
 
-@pytest.mark.skip
+#@pytest.mark.skip
 def test_swap_first_item_from_their_empty_returns_false():
     item_a = Item(category="clothing")
     item_b = Item(category="clothing")
diff --git a/tests/unit_tests/test_wave_05.py b/tests/unit_tests/test_wave_05.py
index 7abea06cd..8dedc9e28 100644
--- a/tests/unit_tests/test_wave_05.py
+++ b/tests/unit_tests/test_wave_05.py
@@ -3,25 +3,25 @@
 from swap_meet.decor import Decor
 from swap_meet.electronics import Electronics
 
-@pytest.mark.skip
+#@pytest.mark.skip
 def test_clothing_has_default_category_and_to_str():
     cloth = Clothing()
     assert cloth.category == "Clothing"
     assert str(cloth) == "The finest clothing you could wear."
 
-@pytest.mark.skip
+#@pytest.mark.skip
 def test_decor_has_default_category_and_to_str():
     decor = Decor()
     assert decor.category == "Decor"
     assert str(decor) == "Something to decorate your space."
 
-@pytest.mark.skip
+#@pytest.mark.skip
 def test_electronics_has_default_category_and_to_str():
     electronics = Electronics()
     assert electronics.category == "Electronics"
     assert str(electronics) == "A gadget full of buttons and secrets."
 
-@pytest.mark.skip
+#@pytest.mark.skip
 def test_items_have_condition_as_float():
     items = [
         Clothing(condition=3.5),
@@ -31,7 +31,7 @@ def test_items_have_condition_as_float():
     for item in items:
         assert item.condition == pytest.approx(3.5)
 
-@pytest.mark.skip
+#@pytest.mark.skip
 def test_items_have_condition_descriptions_that_are_the_same_regardless_of_type():
     items = [
         Clothing(condition=5),
diff --git a/tests/unit_tests/test_wave_06.py b/tests/unit_tests/test_wave_06.py
index 1f7065ab4..ff0fb729a 100644
--- a/tests/unit_tests/test_wave_06.py
+++ b/tests/unit_tests/test_wave_06.py
@@ -4,7 +4,7 @@
 from swap_meet.decor import Decor
 from swap_meet.electronics import Electronics
 
-@pytest.mark.skip
+#@pytest.mark.skip
 def test_best_by_category():
     item_a = Clothing(condition=2.0)
     item_b = Decor(condition=2.0)
@@ -20,7 +20,7 @@ def test_best_by_category():
     assert best_item.category == "Clothing"
     assert best_item.condition == pytest.approx(4.0)
 
-@pytest.mark.skip
+#@pytest.mark.skip
 def test_best_by_category_no_matches_is_none():
     item_a = Decor(condition=2.0)
     item_b = Decor(condition=2.0)
@@ -33,7 +33,7 @@ def test_best_by_category_no_matches_is_none():
 
     assert best_item is None
 
-@pytest.mark.skip
+#@pytest.mark.skip
 def test_best_by_category_with_duplicates():
     # Arrange
     item_a = Clothing(condition=2.0)
@@ -50,7 +50,7 @@ def test_best_by_category_with_duplicates():
     assert best_item.category == "Clothing"
     assert best_item.condition == pytest.approx(4.0)
 
-@pytest.mark.skip
+#@pytest.mark.skip
 def test_swap_best_by_category():
     # Arrange
     # me
@@ -76,16 +76,20 @@ def test_swap_best_by_category():
         their_priority="Decor"
     )
 
-    raise Exception("Complete this test according to comments below.")
+    #raise Exception("Complete this test according to comments below.")
     # *********************************************************************
     # ****** Complete Assert Portion of this test **********
     # *********************************************************************
     # Assertions should check:
     # - That the results is truthy
+    assert result
     # - That tai and jesse's inventories are the correct length
+    assert len(jesse.inventory) == 3
+    assert len(tai.inventory) == 3
     # - That all the correct items are in tai and jesse's inventories, including the items which were swapped from one vendor to the other
-
-@pytest.mark.skip
+    assert tai.get_best_by_category("Decor").category == "Decor"
+    assert jesse.get_best_by_category("Clothing").category == "Clothing"
+#@pytest.mark.skip
 def test_swap_best_by_category_reordered():
     # Arrange
     item_a = Decor(condition=2.0)
@@ -109,16 +113,20 @@ def test_swap_best_by_category_reordered():
         their_priority="Decor"
     )
 
-    raise Exception("Complete this test according to comments below.")
+    #raise Exception("Complete this test according to comments below.")
     # *********************************************************************
     # ****** Complete Assert Portion of this test **********
     # *********************************************************************
     # Assertions should check:
     # - That result is truthy
+    assert result 
     # - That tai and jesse's inventories are the correct length
+    assert len(tai.inventory) == 3
+    assert len(jesse.inventory) == 3
     # - That all the correct items are in tai and jesse's inventories, and that the items that were swapped are not there
-
-@pytest.mark.skip
+    assert tai.get_best_by_category("Decor").category == "Decor"
+    assert jesse.get_best_by_category("Clothing").category == "Clothing"
+#@pytest.mark.skip
 def test_swap_best_by_category_no_inventory_is_false():
     tai = Vendor(
         inventory=[]
@@ -144,7 +152,7 @@ def test_swap_best_by_category_no_inventory_is_false():
     assert item_b in jesse.inventory
     assert item_c in jesse.inventory
 
-@pytest.mark.skip
+#@pytest.mark.skip
 def test_swap_best_by_category_no_other_inventory_is_false():
     item_a = Clothing(condition=2.0)
     item_b = Decor(condition=4.0)
@@ -170,7 +178,7 @@ def test_swap_best_by_category_no_other_inventory_is_false():
     assert item_b in tai.inventory
     assert item_c in tai.inventory
 
-@pytest.mark.skip
+#@pytest.mark.skip
 def test_swap_best_by_category_no_match_is_false():
     # Arrange
     item_a = Decor(condition=2.0)
@@ -194,16 +202,25 @@ def test_swap_best_by_category_no_match_is_false():
         their_priority="Clothing"
     )
 
-    raise Exception("Complete this test according to comments below.")
+    #raise Exception("Complete this test according to comments below.")
     # *********************************************************************
     # ****** Complete Assert Portion of this test **********
     # *********************************************************************
     # Assertions should check:
     # - That result is falsy
+    assert not result
     # - That tai and jesse's inventories are the correct length
+    assert len(tai.inventory) == 3
+    assert len(jesse.inventory) == 3
     # - That all the correct items are in tai and jesse's inventories
+    assert item_a in tai.inventory
+    assert item_b in tai.inventory
+    assert item_c in tai.inventory
+    assert item_d in jesse.inventory
+    assert item_e in jesse.inventory
+    assert item_f in jesse.inventory
 
-@pytest.mark.skip
+#@pytest.mark.skip
 def test_swap_best_by_category_no_other_match_is_false():
     # Arrange
     item_a = Decor(condition=2.0)
@@ -227,11 +244,20 @@ def test_swap_best_by_category_no_other_match_is_false():
         their_priority="Decor"
     )
 
-    raise Exception("Complete this test according to comments below.")
+    #raise Exception("Complete this test according to comments below.")
     # *********************************************************************
     # ****** Complete Assert Portion of this test **********
     # *********************************************************************
     # Assertions should check:
     # - That result is falsy
+    assert not result
     # - That tai and jesse's inventories are the correct length
+    assert len(tai.inventory) == 3
+    assert len(jesse.inventory) == 3
     # - That all the correct items are in tai and jesse's inventories
+    assert item_a in tai.inventory
+    assert item_b in tai.inventory
+    assert item_c in tai.inventory
+    assert item_d in jesse.inventory
+    assert item_e in jesse.inventory
+    assert item_f in jesse.inventory