Update langgraph_agent.py

langgraph_agent.py

@@ -85,6 +85,7 @@ def arvix_search(query: str) -> dict:
 # HF_API_TOKEN is no longer directly needed for describe_image as that tool is removed.
 # But keeping InferenceClient initialization for completeness if other HF tools might be added later.
 HF_API_TOKEN = os.getenv("HF_API_TOKEN")
+MODEL = os.getenv("MODEL")
 HF_INFERENCE_CLIENT = None
 if HF_API_TOKEN:
     HF_INFERENCE_CLIENT = InferenceClient(token=HF_API_TOKEN)
@@ -187,7 +188,7 @@ sys_msg = SystemMessage(content=system_prompt)
 def build_graph(provider: str = "gemini"):
     if provider == "gemini":
         llm = ChatGoogleGenerativeAI(
-            model="gemini-2.5-pro-preview-05-06",
+            model=MODEL,
             temperature=1.0,
             max_retries=2,
             api_key=GEMINI_API_KEY,