Information for React I found useful
https://auth0.com/blog/secure-your-react-and-redux-app-with-jwt-authentication/ this had a sample project that showed how to setup redux and react and explains the redux ecosystem of store, actions, action creators, reducers etc.
It has a nice example of redux middleware ( check out the source and look in middleware/api.js )
Configure CakePHP 3.x
First follow the direction in the bravo-kernel series here:
Starting with the above there is a chain of posts that take you from start to finish of getting CakePHP API ready.
If using Chrome and the fetch() method you will run into all sort of 501 OPTION not supported errors when trying to get access to your CakePHP API from React
This posting makes a very clean fix:
You will need to have some understanding of how to integrate it into CakePHP because it is very nifty middleware: https://book.cakephp.org/3.0/en/controllers/middleware.html#using-middleware