LangChain

pip install langchain

import json
from urllib.request import Request, urlopen
from langchain.tools import tool

@tool
def langsearch(query: str) -> str:
    """Search the web for evidence and return source URLs with context."""
    request = Request(
        "https://api.langsearch.com/v1/web-search",
        data=json.dumps({"query": query, "count": 5, "contents": {"text": True}}).encode(),
        headers={
            "Authorization": "Bearer YOUR_LANGSEARCH_API_KEY",
            "Content-Type": "application/json"
        }
    )
    with urlopen(request, timeout=30) as response:
        payload = json.load(response)
    sources = [{
        "title": item.get("name"),
        "url": item["url"],
        "context": item.get("text") or item.get("snippet") or ""
    } for item in payload["data"]["webPages"]["value"]]
    return json.dumps({"sources": sources, "usage": payload["usage"]}, ensure_ascii=False)