from fastapi import FastAPI, Request
from datetime import datetime, timezone

app = FastAPI()

@app.get("/")
async def read_root(request: Request):
    client_host = request.client.host
    return {
        "message": "ハローワールド！！",
        "client_ip": client_host,
        "current_time_utc": datetime.now(timezone.utc).isoformat()
    }