Local JSON

Local JSON saves field group, post type, and taxonomy definitions as JSON files whenever they are edited. These files can be kept in version control, code-reviewed, and synced back into the database on other environments.

Save and load locations

By default, files are written to and loaded from an acf-json directory in the active theme. The locations are configurable:

• acf/settings/save_json — the directory new files are written to.
• acf/json/save_paths — the full list of candidate save directories.
• acf/settings/load_json / acf/json/load_paths — the directories files are loaded from.

add_filter( 'acf/settings/save_json', function () {
    return get_stylesheet_directory() . '/my-json';
} );

Multisite

On multisite installations, Local JSON files are only written for network super admins by default. Other requests — site administrators, WP-Cron, and WP-CLI commands run without a super admin --user — may only write to save path directories inside the current site’s uploads directory, the only filesystem location WordPress isolates per site. The sites subdirectory of the uploads directory is always excluded, because on the main site it contains the other sites’ files.

This prevents a site administrator from modifying field group definitions in locations shared across the network, such as a theme’s acf-json directory. Reading (loading) Local JSON is unaffected.

To let a site write Local JSON without super admin involvement, point its save location at an existing directory inside that site’s uploads directory:

add_filter( 'acf/settings/save_json', function () {
    $uploads = wp_get_upload_dir();
    return $uploads['basedir'] . '/scf-json';
} );

Note that the uploads directory is publicly readable on most servers, and files there are typically not tracked in version control. Workflows that keep Local JSON in a shared, version-controlled location on multisite should perform field group changes as a network super admin.