Handle None for unconnected number ports

app.py

@@ -54,10 +54,16 @@ def _save(image: Image.Image) -> str:
     return path
 
 
+def _steps(value, default: int = 40) -> int:
+    # Unconnected number ports arrive as None; function defaults are not
+    # applied because the workflow executor passes arguments positionally.
+    return default if value is None else int(value)
+
+
 @spaces.GPU(duration=120)
 def text_to_image(prompt: str, steps: int = 40) -> str:
     """Generate an image from a text prompt with Qwen-Image 2.1."""
-    image = pipe(prompt, num_inference_steps=int(steps)).images[0]
+    image = pipe(prompt, num_inference_steps=_steps(steps)).images[0]
     return _save(image)
 
 
@@ -65,7 +71,7 @@ def text_to_image(prompt: str, steps: int = 40) -> str:
 def edit_image(image, instruction: str, steps: int = 40) -> str:
     """Edit a condition image following an instruction (image-conditioned
     generation with Qwen-Image 2.1)."""
-    edited = pipe(instruction, image=_to_pil(image), num_inference_steps=int(steps)).images[0]
+    edited = pipe(instruction, image=_to_pil(image), num_inference_steps=_steps(steps)).images[0]
     return _save(edited)