main.py

import os
from fastapi import FastAPI
from playwright.sync_api import sync_playwright
#   ↑ 同期版だと "It looks like you are using Playwright Sync API inside the asyncio loop" 
#     と怒られる場合がある。
#     その場合は下記の async版を使い、エンドポイントも async def にする。
# from playwright.async_api import async_playwright

app = FastAPI()

@app.get("/")
def read_root():
    return {
        "message": "Visit /save_mhtml to capture MHTML. Then check the dev mode to see if the file is there."
    }

@app.get("/save_mhtml")
def save_mhtml():
    """
    /save_mhtml にアクセスしたタイミングで外部URLを読み込み、MHTMLを保存する。
    ここで失敗しても起動時には関係ないので、Devモードが落ちるリスクが減る。
    """
    url = "https://civitai.com/models/1055452/akashicpulse"
    output_path = "akashicpulse.mhtml"

    try:
        with sync_playwright() as p:
            browser = p.chromium.launch(headless=True)
            page = browser.new_page()
            page.goto(url, wait_until="networkidle", timeout=60000)

            cdp_session = page.context.new_cdp_session(page)
            snapshot = cdp_session.send("Page.captureSnapshot", {"format": "mhtml"})
            browser.close()

        with open(output_path, "w", encoding="utf-8") as f:
            f.write(snapshot)

        return {
            "status": "success",
            "message": f"MHTML saved to {os.path.abspath(output_path)}"
        }
    except Exception as e:
        return {
            "status": "error",
            "message": str(e)
        }