LangChain 接入老张API：ChatOpenAI 与 OpenAIEmbeddings 配置

pip install langchain-openai
export LAOZHANG_API_KEY="你的老张API密钥"

import os
from langchain_openai import ChatOpenAI

llm = ChatOpenAI(
    model="gpt-6-sol",
    base_url="https://api.laozhang.ai/v1",
    api_key=os.environ["LAOZHANG_API_KEY"],
)

print(llm.invoke("用一句话介绍 LangChain").content)

from langchain_core.tools import tool


@tool
def get_weather(city: str) -> str:
    """查询城市天气。"""
    return f"{city}：晴"


ai_message = llm.bind_tools([get_weather]).invoke("巴黎天气怎么样？请调用工具。")
print(ai_message.tool_calls)

for chunk in llm.stream("从 1 数到 5"):
    print(chunk.content, end="", flush=True)

llm = ChatOpenAI(
    model="gpt-6-sol",
    base_url="https://api.laozhang.ai/v1",
    api_key=os.environ["LAOZHANG_API_KEY"],
    use_responses_api=True,
)
print(llm.invoke("用一句话介绍 Responses API").text)

from langchain_openai import OpenAIEmbeddings

embeddings = OpenAIEmbeddings(
    model="text-embedding-3-small",
    base_url="https://api.laozhang.ai/v1",
    api_key=os.environ["LAOZHANG_API_KEY"],
)
vectors = embeddings.embed_documents(["你好", "世界"])
print(len(vectors), len(vectors[0]))  # 2 1536