Update langgraph_agent.py

langgraph_agent.py

@@ -83,14 +83,14 @@ with open("prompt.txt", "r", encoding="utf-8") as f:
 sys_msg = SystemMessage(content=system_prompt)
 
 
-def build_graph(provider: str = "openai"):
+def build_graph(provider: str = "gemini"):
     """Build the LangGraph agent with chosen LLM (default: Gemini)."""
-    if provider == "openai":
+    if provider == "gemini":
         lllm = ChatGoogleGenerativeAI(
         model= "gemini-2.5-pro-preview-05-06",
         temperature=1.0,
         max_retries=2,
-        google_api_key=api_key,
+        google_api_key=GEMINI_API_KEY,
 )