A simple, straight-forward Google Merchant Center feed generator, according to the newest specs published by Google in 2025.
Install as you would install any other extension, and you'll find it in extensions - feeds. Enable it, and that's it. On the URL it provides, you will always find the most current feed suitable for publishing in Google Merchant Center.
You can easily automate the pulling of this URL and your feed, with a server-side cron job.