Update agent.py

agent.py

@@ -0,0 +1,40 @@
+import os
+from langchain_google_genai import ChatGoogleGenerativeAI
+from langgraph.graph import START, StateGraph, MessagesState
+from langgraph.prebuilt import tools_condition
+from langgraph.prebuilt import ToolNode
+from langchain_core.messages import SystemMessage, HumanMessage
+from tools import *
+
+tools = [add, substract, multiply, divide, web_search]
+
+class AgentState(TypedDict):
+    messages: Annotated[list[AnyMessage], add_messages]
+
+def assistant(state: AgentState):
+    return {
+        "messages": [chat_with_tools.invoke(state["messages"])],
+    }
+
+def build_agent():
+    llm = ChatGoogleGenerativeAI(model="gemini-2.0-flash", temperature=0)
+    llm.bind_tools(tools)
+
+    ## The graph
+    builder = StateGraph(AgentState)
+    
+    # Define nodes: these do the work
+    builder.add_node("assistant", assistant)
+    builder.add_node("tools", ToolNode(tools))
+    
+    # Define edges: these determine how the control flow moves
+    builder.add_edge(START, "assistant")
+    builder.add_conditional_edges(
+        "assistant",
+        # If the latest message requires a tool, route to tools
+        # Otherwise, provide a direct response
+        tools_condition,
+    )
+    builder.add_edge("tools", "assistant")
+
+    return builder.compile()