app.py

from pytubefix import YouTube
from pytubefix.cli import on_progress
from flask import Flask
from flask_cors import CORS

app = Flask(__name__)
CORS(app)

@app.route('/')
def index():
    return "Hello, World!"


@app.route('/api/video/<id>')
def video_id(id):
    url = f"https://www.youtube.com/watch?v={id}"

    yt = YouTube(url, on_progress_callback=on_progress)

    ys = yt.streams.get_highest_resolution()

    return {
        "title": yt.title,
        "url": ys.url,
        "thumbnail": yt.thumbnail_url,
        "description": yt.description
    }