diff --git a/pixelle_video/config/manager.py b/pixelle_video/config/manager.py
index 1b0ef1b..9966e67 100644
--- a/pixelle_video/config/manager.py
+++ b/pixelle_video/config/manager.py
@@ -147,8 +147,7 @@ class ConfigManager:
         updates = {}
         if comfyui_url is not None:
             updates["comfyui_url"] = comfyui_url
-        if runninghub_api_key is not None:
-            updates["runninghub_api_key"] = runninghub_api_key
+        updates["runninghub_api_key"] = runninghub_api_key
         
         if updates:
             self.update({"comfyui": updates})
diff --git a/pixelle_video/config/schema.py b/pixelle_video/config/schema.py
index 4a84dac..7884c85 100644
--- a/pixelle_video/config/schema.py
+++ b/pixelle_video/config/schema.py
@@ -62,7 +62,7 @@ class ImageSubConfig(BaseModel):
 class ComfyUIConfig(BaseModel):
     """ComfyUI configuration (includes global settings and service-specific configs)"""
     comfyui_url: str = Field(default="http://127.0.0.1:8188", description="ComfyUI Server URL")
-    runninghub_api_key: str = Field(default="", description="RunningHub API Key (optional)")
+    runninghub_api_key: Optional[str] = Field(default=None, description="RunningHub API Key (optional)")
     tts: TTSSubConfig = Field(default_factory=TTSSubConfig, description="TTS-specific configuration")
     image: ImageSubConfig = Field(default_factory=ImageSubConfig, description="Image-specific configuration")