This question explores WordPress and addresses practical considerations related to: How can I add custom fields to a WordPress REST API response?

How can I add custom fields to a WordPress REST API response?

Ask any question about WordPress here... and get an instant response.

Post this Question & Answer:

How can I add custom fields to a WordPress REST API response?

Asked on Mar 06, 2026

Answer

Previous Question Next Question

To add custom fields to a WordPress REST API response, you can use the `register_rest_field` function. This function allows you to include additional data in the API response for a specific post type or taxonomy.

<!-- BEGIN COPY / PASTE -->
    function add_custom_fields_to_rest_api() {
        register_rest_field('post', 'custom_field', array(
            'get_callback' => function($post_arr) {
                return get_post_meta($post_arr['id'], 'custom_field_key', true);
            },
            'update_callback' => null,
            'schema' => null,
        ));
    }
    add_action('rest_api_init', 'add_custom_fields_to_rest_api');
    <!-- END COPY / PASTE -->

Additional Comment:

This example adds a custom field to the "post" post type in the REST API response.
Replace "custom_field_key" with the actual meta key of your custom field.
The `get_callback` function retrieves the custom field value using `get_post_meta`.
You can modify the `register_rest_field` parameters to suit your needs, such as adding an `update_callback` for writable fields.

✅ Answered with WordPress best practices.

Ask any question about WordPress here... and get an instant response.

How can I add custom fields to a WordPress REST API response?

Asked on Mar 06, 2026

Answer

Real Questions. Clear Answers.