Update app.py

app.py

@@ -10,7 +10,7 @@ import unicodedata
 from typing import TypedDict, Annotated
  
 from langchain_core.messages import AnyMessage, HumanMessage, SystemMessage
-from langchain_openai import ChatOpenAI
+from langchain_huggingface import ChatHuggingFace, HuggingFaceEndpoint
 from langchain_core.tools import tool
 from langchain_community.tools import DuckDuckGoSearchRun
 from langchain_community.utilities import WikipediaAPIWrapper
@@ -134,13 +134,14 @@ class BasicAgent:
  
         # Pattern esatto dal notebook del corso:
         # llm.bind_tools() + StateGraph costruito manualmente
-        llm = ChatOpenAI(
-            model="Qwen/Qwen2.5-72B-Instruct",
-            base_url="https://router.huggingface.co/v1",
-            api_key=os.getenv("HF_TOKEN"),
+        endpoint = HuggingFaceEndpoint(
+            repo_id="Qwen/Qwen2.5-72B-Instruct",        # tool calling nativo
+            huggingfacehub_api_token=os.getenv("HF_TOKEN"),
+            task="conversational",
+            max_new_tokens=1024,
             temperature=0.1,
-            max_tokens=1024,
         )
+        llm = ChatHuggingFace(llm=endpoint, verbose=False)
         self.llm_with_tools = llm.bind_tools(tools, parallel_tool_calls=False)
  
         # Grafo ReAct: assistant → tools → assistant (loop)