Update app.py

app.py

@@ -84,7 +84,21 @@ css_overrides = """
 }
 """
 
-
+# --- Helper Functions ---
+# -*- coding: utf-8 -*-
+def sanitize_for_api(s: str) -> str:
+    """
+    Turn any “smart quotes” into plain ASCII quotes (and similarly
+    for the common apostrophes) so we never slip non-ASCII into
+    our JSON encoder.
+    """
+    return (
+        s
+        .replace("\u201c", '"')
+        .replace("\u201d", '"')
+        .replace("\u2018", "'")
+        .replace("\u2019", "'")
+    )
 
 
 # --- Enhanced Configuration ---
@@ -302,6 +316,7 @@ def convert_code(
     # Create client and prompt
     client = openai.OpenAI(base_url="https://openrouter.ai/api/v1", api_key=api_key)
     prompt = create_conversion_prompt(source_code, source_lang, target_lang)
+    prompt = sanitize_for_api(prompt)
     
     try:
         # Make the API call