diff --git a/src/nkode_api.py b/src/nkode_api.py
index d425ab0..3ddfdce 100644
--- a/src/nkode_api.py
+++ b/src/nkode_api.py
@@ -1,5 +1,7 @@
+from dataclasses import dataclass, field
 from uuid import UUID, uuid4
-from pydantic import BaseModel
+from typing import Dict, List, Tuple
+
 from src.customer import Customer
 from src.models import NKodePolicy, KeypadSize
 from src.user import User
@@ -9,9 +11,10 @@ from src.user_interface import UserInterface
 from src.customer_attributes import CustomerAttributes
 
 
-class NKodeAPI(BaseModel):
-    customers: dict[UUID, Customer] = {}
-    signup_sessions: dict[UUID, UserSignupSession] = {}
+@dataclass
+class NKodeAPI:
+    customers: Dict[UUID, Customer] = field(default_factory=dict)
+    signup_sessions: Dict[UUID, UserSignupSession] = field(default_factory=dict)
 
     def create_new_customer(self, keypad_size: KeypadSize, nkode_policy: NKodePolicy) -> UUID:
         new_customer = Customer(
@@ -23,7 +26,7 @@ class NKodeAPI(BaseModel):
         self.customers[new_customer.customer_id] = new_customer
         return new_customer.customer_id
 
-    def generate_signup_interface(self, customer_id: UUID) -> tuple[UUID, list[int]]:
+    def generate_signup_interface(self, customer_id: UUID) -> Tuple[UUID, List[int]]:
         if customer_id not in self.customers.keys():
             raise ValueError(f"Customer with ID '{customer_id}' does not exist")
         customer = self.customers[customer_id]
@@ -43,9 +46,9 @@ class NKodeAPI(BaseModel):
             self,
             username: str,
             customer_id: UUID,
-            key_selection: list[int],
+            key_selection: List[int],
             session_id: UUID
-    ) -> list[int]:
+    ) -> List[int]:
         if customer_id not in self.customers.keys():
             raise ValueError(f"Customer ID {customer_id} not found")
         customer = self.customers[customer_id]
@@ -60,7 +63,7 @@ class NKodeAPI(BaseModel):
             self,
             username: str,
             customer_id: UUID,
-            confirm_key_entry: list[int],
+            confirm_key_entry: List[int],
             session_id: UUID
     ) -> bool:
         if session_id not in self.signup_sessions.keys():
@@ -88,7 +91,7 @@ class NKodeAPI(BaseModel):
         del self.signup_sessions[session_id]
         return True
 
-    def get_login_interface(self, username: str, customer_id: UUID) -> list[int]:
+    def get_login_interface(self, username: str, customer_id: UUID) -> List[int]:
         if customer_id not in self.customers.keys():
             raise ValueError("Customer ID not found")
         customer = self.customers[customer_id]
@@ -98,7 +101,7 @@ class NKodeAPI(BaseModel):
         user.user_interface.partial_interface_shuffle()
         return user.user_interface.interface
 
-    def login(self, customer_id: UUID, username: str, key_selection: list[int]) -> bool:
+    def login(self, customer_id: UUID, username: str, key_selection: List[int]) -> bool:
         if customer_id not in self.customers.keys():
             raise ValueError("Customer ID not found")
         customer = self.customers[customer_id]
@@ -107,4 +110,4 @@ class NKodeAPI(BaseModel):
     def renew_attributes(self, customer_id: UUID) -> bool:
         if customer_id not in self.customers.keys():
             raise ValueError("Customer ID not found")
-        return self.customers[customer_id].renew_keys()
\ No newline at end of file
+        return self.customers[customer_id].renew_keys()