change model from hf to gemini

app.py

@@ -1,4 +1,5 @@
 import os
+import getpass
 
 from typing import TypedDict, Annotated
 from langgraph.graph.message import add_messages
@@ -6,18 +7,17 @@ from langchain_core.messages import AnyMessage, HumanMessage, AIMessage
 from langgraph.prebuilt import ToolNode
 from langgraph.graph import START, StateGraph
 from langgraph.prebuilt import tools_condition
-from langchain_huggingface import HuggingFaceEndpoint, ChatHuggingFace
+from langchain.chat_models import init_chat_model
 
 from tools import *
 
+if not os.environ.get("GOOGLE_API_KEY"):
+  os.environ["GOOGLE_API_KEY"] = getpass.getpass("Enter API key for Google Gemini: ")
+
 # Generate the chat interface, including the tools
-llm = HuggingFaceEndpoint(
-    repo_id="Qwen/Qwen2.5-Coder-32B-Instruct",
-    huggingfacehub_api_token=os.environ["HUGGINGFACEHUB_API_TOKEN"],
-)
+chat = init_chat_model("gemini-2.5-flash", model_provider="google_genai")
 
-chat = ChatHuggingFace(llm=llm, verbose=True)
-tools = [search_tool, weather_info_tool, hub_stats_tool]
+tools = [guest_info_tool, weather_info_tool, hub_stats_tool, search_tool]
 chat_with_tools = chat.bind_tools(tools)
 
 # Generate the AgentState and Agent graph

requirements.txt

@@ -1,5 +1,5 @@
 datasets
 langgraph
-langchain_huggingface
+langchain-google-genai
 langchain_community
 rank_bm25