diff --git a/src/defi/dex.py b/src/defi/dex.py
new file mode 100644
index 000000000..71656b1b6
--- /dev/null
+++ b/src/defi/dex.py
@@ -0,0 +1,113 @@
+from collections import defaultdict
+import time
+
+class Token:
+    def __init__(self, name, symbol, total_supply):
+        self.name = name
+        self.symbol = symbol
+        self.total_supply = total_supply
+        self.balances = defaultdict(int)
+
+    def transfer(self, from_address, to_address, amount):
+        if self.balances[from_address] < amount:
+            raise ValueError("Insufficient balance")
+        self.balances[from_address] -= amount
+        self.balances[to_address] += amount
+
+    def mint(self, to_address, amount):
+        self.balances[to_address] += amount
+        self.total_supply += amount
+
+class Order:
+    def __init__(self, order_id, user, token, amount, price, order_type):
+        self.order_id = order_id
+        self.user = user
+        self.token = token
+        self.amount = amount
+        self.price = price
+        self.order_type = order_type  # 'buy' or 'sell'
+        self.timestamp = time.time()
+
+class DEX:
+    def __init__(self):
+        self.order_book = defaultdict(list)  # token -> list of orders
+        self.order_id_counter = 0
+
+    def place_order(self, user, token, amount, price, order_type):
+        if order_type not in ['buy', 'sell']:
+            raise ValueError("Order type must be 'buy' or 'sell'")
+        order = Order(self.order_id_counter, user, token, amount, price, order_type)
+        self.order_book[token].append(order)
+        self.order_id_counter += 1
+        print(f"Placed {order_type} order: {amount} {token.symbol} at {price} by {user}")
+
+        # Attempt to match orders
+        self.match_orders(token)
+
+    def match_orders(self, token):
+        buy_orders = sorted([o for o in self.order_book[token] if o.order_type == 'buy'], key=lambda x: -x.price)
+        sell_orders = sorted([o for o in self.order_book[token] if o.order_type == 'sell'], key=lambda x: x.price)
+
+        while buy_orders and sell_orders:
+            buy_order = buy_orders[0]
+            sell_order = sell_orders[0]
+
+            if buy_order.price >= sell_order.price:
+                trade_amount = min(buy_order.amount, sell_order.amount)
+                trade_price = sell_order.price
+
+                # Execute trade
+                print(f"Executed trade: {trade_amount} {token.symbol} at {trade_price} between {buy_order.user} and {sell_order.user}")
+
+                # Update order amounts
+                buy_order.amount -= trade_amount
+                sell_order.amount -= trade_amount
+
+                # Remove completed orders
+                if buy_order.amount == 0:
+                    buy_orders.pop(0)
+                if sell_order.amount == 0:
+                    sell_orders.pop(0)
+
+            else:
+                break  # No more matches possible
+
+    def cancel_order(self, user, order_id, token):
+        for order in self.order_book[token]:
+            if order.order_id == order_id and order.user == user:
+                self.order_book[token].remove(order)
+                print(f"Cancelled order {order_id} for {user}")
+                return
+        print("Order not found or not authorized to cancel.")
+
+# Example usage
+if __name__ == "__main__":
+    # Create tokens
+    token_a = Token("TokenA", "TKA", 1000000)
+    token_b = Token("TokenB", "TKB", 1000000)
+
+    # Mint some tokens for the user
+    token_a.mint("user1", 10000)
+    token_b.mint("user2", 10000)
+
+    # Create a DEX
+    dex = DEX()
+
+    # User places orders
+    dex.place_order("user1", token_a, 100, 10, 'buy')  # User1 wants to buy 100 TKA at 10
+    dex.place_order("user2", token_a, 100, 9, 'sell')  # User 2 wants to sell 100 TKA at 9
+
+    # User places another order
+    dex.place_order("user1", token_a, 50, 11, 'buy')  # User1 wants to buy 50 TKA at 11
+    dex.place_order("user2", token_a, 50, 10, 'sell')  # User2 wants to sell 50 TKA at 10
+
+    # User cancels an order
+    dex.cancel_order("user1", 0, token_a)  # User1 cancels their first buy order
+
+    # User places a new order
+    dex.place_order("user2", token_a, 30, 8, 'sell')  # User2 wants to sell 30 TKA at 8
+
+    # Check remaining orders
+    print("Remaining orders for TokenA:")
+    for order in dex.order_book[token_a]:
+        print(f"Order ID: {order.order_id}, User: {order.user}, Amount: {order.amount}, Price: {order.price}, Type: {order.order_type}")