如何向 ReAct Agent 添加线程级内存¶
本指南将展示如何向预构建的 ReAct agent 添加内存。请参阅本教程，了解如何开始使用预构建的 ReAct agent
我们可以通过将 checkpointer 传递给 create_react_agent 函数，向 agent 添加内存。
设置¶
首先，让我们安装所需的软件包并设置我们的 API 密钥
import getpass
import os
def _set_env(var: str):
if not os.environ.get(var):
os.environ[var] = getpass.getpass(f"{var}: ")
_set_env("OPENAI_API_KEY")
设置 LangSmith 以进行 LangGraph 开发
注册 LangSmith 以快速发现问题并提高 LangGraph 项目的性能。LangSmith 允许您使用跟踪数据来调试、测试和监控使用 LangGraph 构建的 LLM 应用程序——阅读更多关于如何开始使用 此处 的信息。
代码¶
# First we initialize the model we want to use.
from langchain_openai import ChatOpenAI
model = ChatOpenAI(model="gpt-4o", temperature=0)
# For this tutorial we will use custom tool that returns pre-defined values for weather in two cities (NYC & SF)
from langchain_core.tools import tool
@tool
def get_weather(location: str) -> str:
"""Use this to get weather information."""
if any([city in location.lower() for city in ["nyc", "new york city"]]):
return "It might be cloudy in nyc"
elif any([city in location.lower() for city in ["sf", "san francisco"]]):
return "It's always sunny in sf"
else:
return f"I am not sure what the weather is in {location}"
tools = [get_weather]
# We can add "chat memory" to the graph with LangGraph's checkpointer
# to retain the chat context between interactions
from langgraph.checkpoint.memory import MemorySaver
memory = MemorySaver()
# Define the graph
from langgraph.prebuilt import create_react_agent
graph = create_react_agent(model, tools=tools, checkpointer=memory)
API 参考：ChatOpenAI | tool | MemorySaver | create_react_agent
用法¶
让我们多次与之交互，以表明它可以记住
def print_stream(stream):
for s in stream:
message = s["messages"][-1]
if isinstance(message, tuple):
print(message)
else:
message.pretty_print()
config = {"configurable": {"thread_id": "1"}}
inputs = {"messages": [("user", "What's the weather in NYC?")]}
print_stream(graph.stream(inputs, config=config, stream_mode="values"))
================================[1m Human Message [0m=================================
What's the weather in NYC?
==================================[1m Ai Message [0m==================================
Tool Calls:
get_weather (call_xM1suIq26KXvRFqJIvLVGfqG)
Call ID: call_xM1suIq26KXvRFqJIvLVGfqG
Args:
city: nyc
=================================[1m Tool Message [0m=================================
Name: get_weather
It might be cloudy in nyc
==================================[1m Ai Message [0m==================================
The weather in NYC might be cloudy.
inputs = {"messages": [("user", "What's it known for?")]}
print_stream(graph.stream(inputs, config=config, stream_mode="values"))
================================[1m Human Message [0m=================================
What's it known for?
==================================[1m Ai Message [0m==================================
New York City (NYC) is known for a variety of iconic landmarks, cultural institutions, and vibrant neighborhoods. Some of the most notable aspects include:
1. **Statue of Liberty**: A symbol of freedom and democracy.
2. **Times Square**: Known for its bright lights, Broadway theaters, and bustling atmosphere.
3. **Central Park**: A large urban park offering a green oasis in the middle of the city.
4. **Empire State Building**: An iconic skyscraper with an observation deck offering panoramic views of the city.
5. **Broadway**: Famous for its world-class theater productions.
6. **Wall Street**: The financial hub of the United States.
7. **Museums**: Including the Metropolitan Museum of Art, the Museum of Modern Art (MoMA), and the American Museum of Natural History.
8. **Diverse Cuisine**: A melting pot of culinary experiences from around the world.
9. **Cultural Diversity**: A rich tapestry of cultures, languages, and traditions.
10. **Fashion**: A global fashion capital, home to New York Fashion Week.
These are just a few highlights of what makes NYC a unique and vibrant city.