Add metadata on llm chain

rag.py

@@ -120,7 +120,12 @@ class Rag:
             chain_input.update(extra_vars)
         
 
-        return self.chain.stream(chain_input)
+        return self.chain.stream(chain_input, config={
+            "metadata" : {
+                "id_user": st.session_state.get("id_user", None),
+                "use_case": st.session_state.get("use_case", None)
+            }
+        })
 
     def clear(self):
         self.document_vector_store = None