diff --git a/splurgebot.py b/splurgebot.py
index a9d7e14..baef422 100644
--- a/splurgebot.py
+++ b/splurgebot.py
@@ -1,39 +1,52 @@
 import datetime
 import os
 import time
+from typing import List
+
 from twilio.rest import Client as TwilioClient
 
-import plaid
+from plaid import Client as PlaidClient
 
 CHECK_FOR_NEW_TRANSACTIONS_EVERY_X_MINUTES = 5
 ALERT_FOR_TRANSACTIONS_GTE = 500
 MY_CELL = os.getenv('MY_CELL')
 MY_TWILIO_NUM = os.getenv('MY_TWILIO_NUM')
-
-plaid_client = plaid.Client(client_id=os.getenv('PLAID_CLIENT_ID'), secret=os.getenv('PLAID_SECRET'),
-                            public_key=os.getenv('PLAID_PUBLIC_KEY'), environment=os.getenv('PLAID_ENV'))
-twilio_client = TwilioClient(os.getenv('TWILIO_SID'), os.getenv('TWILIO_TOKEN'))
-
+PLAID_ENV = os.getenv('PLAID_ENV') or 'sandbox'
 # this is an access ID from Plaid for a specific user and bank/credit account
 PLAID_ACCESS_ID = os.getenv('PLAID_ACCESS_ID')
 
+plaid_client = PlaidClient(client_id=os.getenv('PLAID_CLIENT_ID'),
+                           secret=os.getenv('PLAID_SECRET'),
+                           public_key=os.getenv('PLAID_PUBLIC_KEY'),
+                           environment=PLAID_ENV)
+
+twilio_client = TwilioClient(os.getenv('TWILIO_SID'),
+                             os.getenv('TWILIO_TOKEN'))
+
 transaction_ids = set()
 
 
-def get_latest_transactions():
-    today = datetime.date.tody().strftime('%Y-%m-%d')
+def get_latest_transactions() -> List[dict]:
+    """get 100 most recent transactions"""
+    today = datetime.date.today().strftime('%Y-%m-%d')
     return [transaction
-            for transaction in plaid_client.Transactions.get(PLAID_ACCESS_ID, '1972-01-01', today)['transactions']
+            for transaction in plaid_client.Transactions.get(
+                    PLAID_ACCESS_ID, '1972-01-01', today)['transactions']
             if transaction['transaction_id'] not in transaction_ids]
 
 
-def alert(transaction):
-    message = (f'hey, a transaction hit your account that exceeds ${ALERT_FOR_TRANSACTIONS_GTE}: ' 
-               f'{transaction["date"]} {transaction["name"]} ${transaction["amount"]}')
-    twilio_client.api.account.messages.create(to=MY_CELL, from_=MY_TWILIO_NUM, body=message)
+def alert(transaction: dict) -> None:
+    message = (
+       'hey, a transaction hit your account that exceeds '
+       f'${ALERT_FOR_TRANSACTIONS_GTE}: '
+       f'{transaction["date"]} {transaction["name"]} ${transaction["amount"]}')
+
+    twilio_client.api.account.messages.create(to=MY_CELL,
+                                              from_=MY_TWILIO_NUM,
+                                              body=message)
 
 
-def main():
+def main() -> None:
     while True:
         for transaction in get_latest_transactions():
             transaction_ids.add(transaction['transaction_id'])