FLAT - the "Frontend Layer API Toolkit" by Sevenval is designed for easy decoupling frontend from backend in modern web applications. It is the preview version of Couper. See couper.io for more details.
This documentation helps building maintainable JSON-based web APIs on top of FLAT.
Create your first FLAT application hands-on and learn the basics in the Tutorial. This is the best place to start.
Browse the recipes in Couper's Cookbook to learn how to accomplish common API development tasks with FLAT. Developers will find plenty of examples here.
Look up detailed usage information about FLAT's nuts and bolts in the Reference.
Learn how to deploy and run FLAT APIs in the Administration section.