telepot_broadcast_sniplet.py

async def command_start(bot, chat_id, args):
    if args['chat_type'] in ('group', 'supergroup'):
        bot.broadcast_targets.append(chat_id)

async def command_broadcast(bot, chat_id, args):
    """
    args = {'user_id': TELEGRM_USER_ID, 'username': TELEGRAM_USER_NAME, 'params': ['hello', 'world']}
    """
    user_id = args['user_id']
    if user_id in bot.mods:
        message = ' '.join(args['params'])
        for group in bot.broadcast_targets:
            await bot.sendMessage(group, message)