change ouptu function of predict as it cannont handle langchain history

app.py

@@ -164,7 +164,7 @@ def predict(message, history, request: gr.Request):
     gpt_response = llm.invoke(
         messages,
         config={
-            "tags": ["Testing", 'RAG-Bot', 'V1'],
+            "tags": ["Testing", 'RAG-Bot', 'V1','Host_on_HF'],
             "metadata": {
                 "rag_llm": "gpt-5-nano",
                 "num_retrieved_docs": len(relevant_docs),
@@ -185,17 +185,17 @@ def predict(message, history, request: gr.Request):
             if line not in seen:          
                 seen.add(line)
                 unique_source_lines.append(line)
-        source_context = "\nSources:\n" + "\n".join(unique_source_lines)
+        source_context = "\nSources:" + "\n".join(unique_source_lines)
 
     except :
-        source_context = "\n".join([
+        source_context = "\nSources:" + "\n".join([
         f"{doc.metadata["source"]}" for i, doc in enumerate(relevant_docs)])
 
     messages.append(AIMessage(content=source_context))
     print(gpt_response.content )
     print(source_context)
     
-    return messages
+    return f"{gpt_response.content} {source_context}"
 
 
 # setup tracking