We'll create fresh WordPress site with WP REST API Custom Fields installed. You have 20 minutes to test the plugin after that site we'll be deleted.
This plugin combines the two of the best WordPress plugins: Advanced Custom Fields and WP REST API.
This plugin is based on the work fromPanman on Github. He was right when he said it would be better as plugin, but it would be even better if it would be available through the WordPress Plugin Repository.
An addition made to this plugin is that each ACF Field van be filtered throug the hook: JSON_META_ACFFIELDNAME (where ACFFIELDNAME depends on the fieldname you’ve added in the Advanced Custom Fields backend.)