update main.py

main.py

@@ -1,7 +1,7 @@
 """
 Main entry point for the agent with memory and human‑in‑the‑loop confirmation.
 
-The agent is built on top of LangChain's `create_agent` API.  It uses a
+The agent is built on top of LangChain's `create_tool_calling_agent` API.  It uses a
 `MemorySaver` checkpoint to keep conversation history across calls, and it
 is configured with `interrupt_before=["tools"]` so that the agent pauses just
 before invoking any tool.  The pause allows us to ask the user for explicit
@@ -24,13 +24,13 @@ from __future__ import annotations
 
 import os
 import json
-from typing import Any, Dict, Iterable, Tuple
+from typing import Any, Dict
 
 from langchain_openai import ChatOpenAI
 from langchain_core.messages import HumanMessage, SystemMessage
 from langgraph.checkpoint.memory import MemorySaver
 from langgraph.types import Command
-from langchain.agents import create_agent
+from langchain.agents import create_tool_calling_agent
 from langchain.tools import tool
 from rich.console import Console
 
@@ -69,11 +69,11 @@ async def get_price(query: Dict[str, Any]) -> str:
     return f"The price of {product} is 42.00 {currency}."
 
 # ---------------------------------------------------------------------------
-# Agent definition using create_agent (LangChain)
+# Agent definition using create_tool_calling_agent (LangChain)
 # ---------------------------------------------------------------------------
 memory = MemorySaver()
 
-agent = create_agent(
+agent = create_tool_calling_agent(
     llm=llm,
     tools=[get_price],
     system_prompt="You are a helpful assistant that can query prices.",
@@ -81,9 +81,6 @@ agent = create_agent(
     interrupt_before=["tools"],  # pause before any tool call
 )
 
-# Compile the agent into a graph with checkpointing.
-graph = agent.compile(checkpointer=memory, interrupt_before=["tools"])
-
 # ---------------------------------------------------------------------------
 # Helper to run the agent and pause before each tool call.
 # ---------------------------------------------------------------------------
@@ -98,10 +95,10 @@ async def ask_and_run(user_input: Dict[str, Any], config: Dict[str, Any]):
         Configuration dictionary that must contain ``configurable`` with
         ``thread_id``.
     """
-    async for chunk in graph.stream(user_input, config=config, stream_mode=["messages", "updates"]):
+    async for chunk in agent.stream(user_input, config=config, stream_mode=["messages", "updates"]):
         # ``chunk`` is a tuple (type, data).
         chunk_type, chunk_data = chunk
-        state = graph.get_state(config)
+        state = agent.get_state(config)
 
         if chunk_type == "messages":
             # Stream token by token.
@@ -120,7 +117,7 @@ async def ask_and_run(user_input: Dict[str, Any], config: Dict[str, Any]):
                 console.print("[red]Action cancelled by user.[/]")
                 break
             # Resume from the same state.
-            await graph.ainvoke(Command(resume=None), config=config)
+            await agent.ainvoke(Command(resume=None), config=config)
 
 # ---------------------------------------------------------------------------
 # Main loop – three examples as requested.