diff --git a/misskey/misskeyapi.py b/misskey/misskeyapi.py
index c8ea7d2..ba21d70 100644
--- a/misskey/misskeyapi.py
+++ b/misskey/misskeyapi.py
@@ -1,25 +1,12 @@
 import requests
 import json
-import uuid
-from typing import (
-    Optional,
-    Any,
-    Union,
-    List,
-    Tuple,
-    Set,
-)
-from urllib.parse import urlparse, urlencode
 import pdb
 
 class MisskeyAPI:
 
     name = 'Python Wrapper for Misskey API'
 
-    __DEFAULT_BASE_URL = 'https://mk.catala.digital'
-    __CALLBACK = f'{__DEFAULT_BASE_URL}/callback'
     __DEFAULT_TIMEOUT = 300
-    __DEFAULT_SCOPES = ['read', 'write']
     __SCOPE_SETS = [
             'read:account', 
             'read:blocks', 
@@ -56,16 +43,20 @@ class MisskeyAPI:
 
     def __init__(
         self,
-        api_base_url=__DEFAULT_BASE_URL,
-        callback=__CALLBACK,
-        permission=__SCOPE_SETS,
-        name: str = 'login',
-        request_timeout=__DEFAULT_TIMEOUT,
-        session=None,
+        api_base_url = None,
+        callback = None,
+        permission = __SCOPE_SETS,
+        name: str = None,
+        request_timeout = __DEFAULT_TIMEOUT,
+        session = None,
         ):
 
         self.api_base_url = api_base_url
-        self.callback = callback
+        if self.api_base_url == None:
+            raise WrapperError("A Misskey instance's URL is required!") 
+        if self.api_base_url != None:
+            self.callback = f'{self.api_base_url}/callback'
+
         self.permission = permission
         self.request_timeout = request_timeout
 
@@ -106,7 +97,6 @@ class MisskeyAPI:
                 response = ret.json()
             else:
                 response = requests.post(self.api_base_url + '/api/app/create', json=params, timeout=self.request_timeout)
-                #response = response.json()
 
         except Exception as e:
 
@@ -115,7 +105,7 @@ class MisskeyAPI:
         return response
 
     def app_show(self, app_id=None, session=None):
-        
+
         params = {
             'appId': app_id
         }
@@ -273,6 +263,9 @@ class MisskeyAPI:
 ##
 # Exceptions
 ##
+class WrapperError(Exception):
+    """Wrapper base class"""
+
 class MisskeyAPIConfigError(Exception):
     """This class exception"""