diff --git a/MagnaSim.py b/MagnaSim.py
index e35f1de..fd38a0f 100644
--- a/MagnaSim.py
+++ b/MagnaSim.py
@@ -111,5 +111,14 @@ def fees_eth(nbr_transaction_eth):
     return fees_eth
 
 def fees_mgn(nbr_transaction_mgn):
-    return
+    """
+    Cette fonction calcule le cout de transfère des tokens magna 
+    basés sur Stellar.
+    There are two special values used to calculate fees:
+        The base fee (currently 100 stroops) is used in transaction fees.
+        The base reserve (currently 0.5 XLM) is used in minimum account balances.
+    100 stroops (0.00001 XLM)
+    """
+    fees_mgn = nbr_transaction_mgn*100
+    return fees_mgn