使用LangGraph构建自主RAG（3）

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设置WebSearch API：

我们使用serperAPI进行网络搜索（谷歌搜索）。其免费层提供2500次免费网络搜索API。它能在1 - 2秒内为给定查询提供谷歌搜索结果。

你可以在这里找到更多详细信息并获取你的 API 密钥此处

ini 复制代码

from langchain_community.utilities import GoogleSerperAPIWrapper
from dotenv import load_dotenv
load_dotenv()
SERPER_API_KEY = os.getenv("SERPER_API_KEY")

search = GoogleSerperAPIWrapper()
# testing the google search API
search.run(query="What are the various vaccines of COVID-19")

输出：

arduino 复制代码

"Different types of COVID-19 vaccines: How they work · mRNA vaccine · mRNA vaccine · Messenger RNA (mRNA) vaccine · Viral vector vaccine · Viral vector vaccine ... First introduced in December 2020, the original COVID mRNA vaccines from both Pfizer and Moderna protected against the original SARS-CoV-2 virus ... Currently, there are two types of COVID-19 vaccines for use in the United States: mRNA, and protein subunit vaccines. None of these vaccines can ... On this page, you will find infographics to explain how different types of vaccines work, including the Pfizer/BioNTech vaccine, the Moderna vaccine and the ... Types of COVID-19 vaccines. Two types of COVID-19 vaccines are recommended for use in the United States: mRNA vaccines. Moderna COVID-19 Vaccine ... List of COVID-19 vaccine authorizations · Contents · Overview maps · Oxford--AstraZeneca · Pfizer--BioNTech · Janssen · Moderna · Sinopharm BIBP · Sputnik V. WHO recommends a simplified single-dose regime for primary immunization for most COVID-19 vaccines which would improve acceptance and uptake and provide ... Find information and answers to your questions about the COVID-19 vaccine, including scheduling, kid's shots, boosters, additional doses, records and more. The California Department of Public Health is dedicated to optimizing the health and well-being of Californians. Find out how the COVID-19 vaccines work, how many doses are needed, possible side effects and who shouldn't get the vaccine."

设置OpenAI API客户端：

我们将使用Open AI API的gpt-5-nano模型进行本次实验。

我选择这个模型是因为我的实验规模很小且复杂度较低。我的提示非常简单。在现实场景中，你可能需要使用更高级的模型（gpt-5-mini / gpt-5）。

参考以下代码：

python 复制代码

from openai import OpenAI
from dotenv import load_dotenv
load_dotenv()
openai_api_key = os.getenv("OPEN_AI_KEY")
def get_llm_response(prompt: str) -> str:
    """Function to get response from LLM"""
    from openai import OpenAI
    client_llm = OpenAI(api_key=openai_api_key)
    response = client_llm.chat.completions.create(
        model="gpt-5-nano",
        messages=[{"role": "user", "content": prompt}]
    )
    return response.choices[0].message.content

## testing the LLM response
prompt = "Explain the theory of relativity in simple terms in 30 words"
response = get_llm_response(prompt)
print(response)

相对论认为，物理定律适用于所有观察者，不存在优先参考系，且没有任何物体的运动速度能超过光速。时间和空间会随运动和引力而弯曲，从根本上使质量和能量等价。

现在场地已经布置好了。让我们开始实施RAG。首先，我们将使用第一个来源（医疗问答）构建一个传统RAG，然后再转向智能体RAG。