diff --git a/bot/fediverse_factory.py b/bot/fediverse_factory.py
index f2a9017..bee5f73 100644
--- a/bot/fediverse_factory.py
+++ b/bot/fediverse_factory.py
@@ -8,9 +8,13 @@ class FediverseServiceFactory:
     """Factory for creating FediverseService implementations based on configuration"""
     
     @staticmethod
-    def create_service() -> FediverseService:
+    def create_service(instance_type: str = None) -> FediverseService:
         """
-        Create a FediverseService implementation based on the configured instance type.
+        Create a FediverseService implementation based on the instance type.
+        
+        Args:
+            instance_type: The type of instance ("misskey" or "pleroma"). 
+                          If None, reads from config.INSTANCE_TYPE
         
         Returns:
             FediverseService implementation (MisskeyService or PleromaService)
@@ -18,14 +22,24 @@ class FediverseServiceFactory:
         Raises:
             ValueError: If the instance type is not supported
         """
-        if config.INSTANCE_TYPE == "misskey":
+        if instance_type is None:
+            instance_type = config.INSTANCE_TYPE
+            
+        instance_type = instance_type.lower()
+        
+        if instance_type == "misskey":
             return MisskeyService()
-        elif config.INSTANCE_TYPE == "pleroma":
+        elif instance_type == "pleroma":
             return PleromaService()
         else:
-            raise ValueError(f"Unsupported instance type: {config.INSTANCE_TYPE}")
+            raise ValueError(f"Unsupported instance type: {instance_type}")
 
 
-def get_fediverse_service() -> FediverseService:
-    """Convenience function to get a FediverseService instance"""
-    return FediverseServiceFactory.create_service()
\ No newline at end of file
+def get_fediverse_service(instance_type: str = None) -> FediverseService:
+    """
+    Convenience function to get a FediverseService instance
+    
+    Args:
+        instance_type: Optional instance type override for testing
+    """
+    return FediverseServiceFactory.create_service(instance_type)
\ No newline at end of file