What WP-API authentication method should I use to interact with anonymous / not-logged visitors?

Question

I am going to track number of plays of a video in my site by both visitors and users. Whenever the video starts playing I am using JavaScript for the event handling in the frontend and write to wp_options or wp_usermeta to track these interactions.

I was going to make an AJAX request to the wp_ajax_$action and wp_ajax_nonpriv_$action hooks but I'd like to use this small task as an opportunity to experiment with the new REST API since I heard it is going to replace the old wp-admin/admin-ajax.php way of doing it on the long run.

How should I approach this?

Answer 1

In WP REST API v2 use the permission_callback found in the Adding Custom Endpoints Docs.

<?php
add_action( 'rest_api_init', function () {
    register_rest_route( 'myplugin/v2', '/author/(?P<id>\d+)', array(
        'methods' => 'GET',
        'callback' => 'my_awesome_func',
        'args' => array(
            'id' => array(
                'validate_callback' => 'is_numeric'
            ),
        ),
        'permission_callback' => function (WP_REST_Request $request) {
            if ( current_user_can( 'edit_others_posts' ) ) {
                return true;
            } 
            else { 
                return false;
            }
        }
    ) );
} );