I used this project to test and learn Recoil. First I found it frustrating to work with atoms and selectors in components, but in the end, I was happy with encapsulating the Recoil API in custom hooks. I used posts and comments from https://jsonplaceholder.typicode.com as mock API. When you add comments they will not be really saved. The example has zero stylings and is not perfect, but helped me to get familiar with Recoil.
In the project directory, you can run:
Open http://localhost:3000 to view it in the browser.
or
Launches the test runner
Hope you find it useful. Glad for any feedback or ideas for improvement!