Alchemy is a Rails content management engine, that you can pluck into any Rails app and can be used headless or as a classic SSR CMS.
The Rails engine can be found in this repo
https://github.com/AlchemyCMS/alchemy_cms
A Devise based user authentication
https://github.com/AlchemyCMS/alchemy_cms/tree/main/devise
Use Alchemy as a headless cms for your frontend application
https://github.com/AlchemyCMS/alchemy-json_api
If you like Alchemy or your company is using Alchemy please consider to sponsor our work over at our OpenCollective.