Update src/chat_langraph.py

src/chat_langraph.py

@@ -227,7 +227,7 @@ def checktool(state: chatstate):
     return "end"
 
 
-tools = [add, reverse, evaluate, run_cmd_command, search_tool, write_file]
+tools = [add, reverse, evaluate, run_cmd_command, search_tool, write_file, plot_graph]
 tool_node = ToolNode(tools=tools)
 llm = llm.bind_tools(tools)