diff --git a/fishy/engine/common/event_handler.py b/fishy/engine/common/event_handler.py
index 612a673..c8105a5 100644
--- a/fishy/engine/common/event_handler.py
+++ b/fishy/engine/common/event_handler.py
@@ -5,8 +5,29 @@ from fishy.engine import SemiFisherEngine
 from fishy.engine.fullautofisher.engine import FullAuto
 
 
-class EngineEventHandler:
+class IEngineHandler:
+    def __init__(self):
+        ...
+
+    def start_event_handler(self):
+        ...
+
+    def toggle_semifisher(self):
+        ...
+
+    def toggle_fullfisher(self):
+        ...
+
+    def check_pixel_val(self):
+        ...
+
+    def quit(self):
+        ...
+
+
+class EngineEventHandler(IEngineHandler):
     def __init__(self, gui_ref):
+        super().__init__()
         self.event_handler_running = True
         self.event = []
 
diff --git a/fishy/gui/config_top.py b/fishy/gui/config_top.py
index 5001347..f8bc6c7 100644
--- a/fishy/gui/config_top.py
+++ b/fishy/gui/config_top.py
@@ -3,6 +3,7 @@ import os
 import typing
 from tkinter.filedialog import askopenfilename
 
+from fishy.engine.common.event_handler import IEngineHandler
 from fishy.helper import helper
 
 from fishy import web
@@ -109,3 +110,10 @@ def start_semifisher_config(gui: 'GUI'):
 
     controls_frame.pack(padx=(5, 5), pady=(5, 5))
     top.start()
+
+
+if __name__ == '__main__':
+    from fishy.gui import GUI
+    gui = GUI(lambda: IEngineHandler())
+    gui.call_in_thread(lambda: start_fullfisher_config(gui))
+    gui.create()
diff --git a/fishy/gui/gui.py b/fishy/gui/gui.py
index 79d8821..14d5f45 100644
--- a/fishy/gui/gui.py
+++ b/fishy/gui/gui.py
@@ -8,7 +8,7 @@ import threading
 from fishy.web import web
 from ttkthemes import ThemedTk
 
-from fishy.engine.common.event_handler import EngineEventHandler
+from fishy.engine.common.event_handler import EngineEventHandler, IEngineHandler
 from fishy.gui import config_top
 from fishy.gui.funcs import GUIFuncs
 from . import main_gui
@@ -18,7 +18,7 @@ from ..helper.helper import wait_until
 
 
 class GUI:
-    def __init__(self, get_engine: Callable[[], EngineEventHandler]):
+    def __init__(self, get_engine: Callable[[], IEngineHandler]):
         self.funcs = GUIFuncs(self)
         self.get_engine = get_engine
 
diff --git a/fishy/helper/config.py b/fishy/helper/config.py
index 896fbc8..838bde3 100644
--- a/fishy/helper/config.py
+++ b/fishy/helper/config.py
@@ -107,7 +107,7 @@ class config:
         :param default: default value to return if key is not found
         :return: config value
         """
-        return default if config._instance[key] is None else config._instance[key]
+        return default if config._instance is None or config._instance[key] is None else config._instance[key]
 
     @staticmethod
     def set(key, value, save=True):
@@ -117,6 +117,9 @@ class config:
         :param value: value to save
         :param save: False if don't want to save right away
         """
+        if config._instance is None:
+            return
+
         config._instance[key] = value
         if save:
             config.save_config()
@@ -135,4 +138,6 @@ class config:
 
     @staticmethod
     def save_config():
+        if config._instance is None:
+            return
         config._instance.save_config()