Update app.py

app.py

@@ -18,6 +18,12 @@ def position_evaluation(fen):
     Returns:
         tuple: (result, error) - Best move with continuation in UCI notation
     """
+    is_valid, err_msg = validate_input(fen)
+    
+    if not is_valid:
+        gr.Warning(f"Invalid input: {err_msg}")
+        return None, err_msg
+    
     print("")
     
     print(f"🤖 Chess position_evaluation: fen={fen}")
@@ -44,6 +50,14 @@ def _noop(*args, **kwargs):
 
 gradio.utils.watchfn_spaces = _noop
 
+def validate_input(fen):
+    is_valid = True
+
+    if fen.len() > 100:
+        is_valid = False
+
+    return is_valid
+
 # Graphical user interface
 
 mcp = gr.Interface(