Tutorial de configuración de LangChain

OPENAI_API_KEY=sk-xxx
BASE_URL=https://api.crazyrouter.com/v1

py -m venv .venv
.\.venv\Scripts\Activate.ps1
python -m pip install -U pip
pip install -U langchain-openai langchain-community
python --version
pip --version

pip install faiss-cpu

python3 -m venv .venv
source .venv/bin/activate
python -m pip install -U pip
pip install -U langchain-openai langchain-community
python --version
pip --version

pip install faiss-cpu

npm init -y
npm install @langchain/openai @langchain/core
node -v
npm -v

npm init -y
npm install @langchain/openai @langchain/core
node -v
npm -v

from langchain_openai import ChatOpenAI

llm = ChatOpenAI(
    model="gpt-5.5",
    api_key="sk-xxx",
    base_url="https://api.crazyrouter.com/v1",
    temperature=0.7,
)

response = llm.invoke("什么是 LangChain？")
print(response.content)

from langchain_openai import OpenAIEmbeddings

embeddings = OpenAIEmbeddings(
    model="text-embedding-3-large",
    api_key="sk-xxx",
    base_url="https://api.crazyrouter.com/v1",
)

vectors = embeddings.embed_documents(["文本一", "文本二"])
print(len(vectors), len(vectors[0]))

from langchain_openai import ChatOpenAI
from langchain_core.prompts import ChatPromptTemplate
from langchain_core.output_parsers import StrOutputParser

llm = ChatOpenAI(
    model="gpt-5.5",
    api_key="sk-xxx",
    base_url="https://api.crazyrouter.com/v1",
)

prompt = ChatPromptTemplate.from_template("用简单的语言解释 {topic}")
chain = prompt | llm | StrOutputParser()

result = chain.invoke({"topic": "量子计算"})
print(result)

from langchain_openai import ChatOpenAI, OpenAIEmbeddings
from langchain_community.vectorstores import FAISS
from langchain_core.prompts import ChatPromptTemplate
from langchain_core.runnables import RunnablePassthrough

llm = ChatOpenAI(
    model="gpt-5.5",
    api_key="sk-xxx",
    base_url="https://api.crazyrouter.com/v1",
)

embeddings = OpenAIEmbeddings(
    model="text-embedding-3-large",
    api_key="sk-xxx",
    base_url="https://api.crazyrouter.com/v1",
)

texts = [
    "Crazyrouter 支持多种 AI 模型协议",
    "Crazyrouter 支持 OpenAI 兼容调用方式",
]

vectorstore = FAISS.from_texts(texts, embeddings)
retriever = vectorstore.as_retriever()

prompt = ChatPromptTemplate.from_template(
    "根据以下上下文回答问题：\n{context}\n\n问题：{question}"
)

chain = {"context": retriever, "question": RunnablePassthrough()} | prompt | llm

result = chain.invoke("Crazyrouter 适合用什么协议接 LangChain？")
print(result.content)

import { ChatOpenAI } from "@langchain/openai";

const llm = new ChatOpenAI({
  model: "gpt-5.5",
  apiKey: process.env.OPENAI_API_KEY,
  configuration: {
    baseURL: "https://api.crazyrouter.com/v1",
  },
  temperature: 0,
});

const response = await llm.invoke("你好");
console.log(response.content);