Safely disable WP REST API - wordpress

Question

I am considering to improve security of my Wordpress website, and in doing so have come across WP REST API being enabled by default (since WP 4.4 if I'm not mistaken).
What is a safe way to disable it?
By "safe" here I mean that it does not cause unexpected side-effects, e.g. does not break any other WP core functionality.
One possible approach would be to use .htaccess rewrite rules, but surprisingly I haven't found any 'official' instructions on doing so.
Any help or recommendation is greatly appreciated :)
Update:
3rd-party plugins is not the solution I am looking for. Although I'm aware there are plenty of them that solve the task, they include many extra features that slow down the website. I would hope there is a one-line solution to this problem without the overhead of an extra plugin.
Update 2:
Here is the official opinion of Wordpress: https://developer.wordpress.org/rest-api/using-the-rest-api/frequently-asked-questions/#can-i-disable-the-rest-api
According to this, the Wordpress team wants future WP functionality to depend on the new REST API. This means there is no guaranteed safe way to disable the REST API.
Let's just hope there are enough security experts taking care of WP security.
Update 3:
A workaround is presented in WordPress API Handbook - you can Require Authentication for All Reque​sts
This makes sure that anonymous access to your website's REST API is disabled, only authenticated requests will work.

Answer 1

From the author original question I've chosen option 2 that came from wordpress official recommendations(https://developer.wordpress.org/rest-api/using-the-rest-api/frequently-asked-questions/#can-i-disable-the-rest-api). So just put in your functions.php to let only logged in users use the rest api (but just cross check original link in case my code block is outdated ;) ):
UPD(01-10-2021):
add_filter( 'rest_authentication_errors', function( $result ) {
// If a previous authentication check was applied,
// pass that result along without modification.
if ( true === $result || is_wp_error( $result ) ) {
return $result;
}
// No authentication has been performed yet.
// Return an error if user is not logged in.
if ( ! is_user_logged_in() ) {
return new WP_Error(
'rest_not_logged_in',
__( 'You are not currently logged in.' ),
array( 'status' => 401 )
);
}
// Our custom authentication check should have no effect
// on logged-in requests
return $result;
});

Answer 2

You can disable it for requests other than localhost:
function restrict_rest_api_to_localhost() {
$whitelist = [ '127.0.0.1', "::1" ];
if( ! in_array($_SERVER['REMOTE_ADDR'], $whitelist ) ){
die( 'REST API is disabled.' );
}
}
add_action( 'rest_api_init', 'restrict_rest_api_to_localhost', 0 );

Answer 3

The accepted answer disables all API calls from unauthenticated users, but nowadays lot of plugins are dependent on this API's functionality.
Disabling all calls will lead to unexpected site behavior which happened in my case also when I used this code.
For example, ContactForm7 makes use of this API for sending contact info to DB (I think) and for ReCaptcha validation.
I think it would be better to disable some (default) endpoints for unauthenticated users like this:
// Disable some endpoints for unauthenticated users
add_filter( 'rest_endpoints', 'disable_default_endpoints' );
function disable_default_endpoints( $endpoints ) {
$endpoints_to_remove = array(
'/oembed/1.0',
'/wp/v2',
'/wp/v2/media',
'/wp/v2/types',
'/wp/v2/statuses',
'/wp/v2/taxonomies',
'/wp/v2/tags',
'/wp/v2/users',
'/wp/v2/comments',
'/wp/v2/settings',
'/wp/v2/themes',
'/wp/v2/blocks',
'/wp/v2/oembed',
'/wp/v2/posts',
'/wp/v2/pages',
'/wp/v2/block-renderer',
'/wp/v2/search',
'/wp/v2/categories'
);
if ( ! is_user_logged_in() ) {
foreach ( $endpoints_to_remove as $rem_endpoint ) {
// $base_endpoint = "/wp/v2/{$rem_endpoint}";
foreach ( $endpoints as $maybe_endpoint => $object ) {
if ( stripos( $maybe_endpoint, $rem_endpoint ) !== false ) {
unset( $endpoints[ $maybe_endpoint ] );
}
}
}
}
return $endpoints;
}
With this, the only endpoints now open are the ones installed by the plugins.
For complete list of endpoints active on your site, see https://YOURSITE.com/wp-json/
Feel free to edit $endpoints_to_remove array as per your requirement.
If you have custom post type, make sure to add those all to the list too.
In my case, I also changed the default endpoint prefix from wp-json to mybrand-api. This should act a deterrent for bots that were making thousands of brute-force requests.
Here is what I did:
// Custom rest api prefix (Make sure to go to Dashboard > Settings > Permalinks and press Save button to flush/rewrite url cache )
add_filter( 'rest_url_prefix', 'rest_api_url_prefix' );
function rest_api_url_prefix() {
return 'mybrand-api';
}

Answer 4

Disabling REST API was not a bad idea, after all.
It actually opened a huge hole in all websites!
In wordpress 4.4 there was a way
Here, I've found a possible solution with .htaccess but should be carefully tested in combination with whatever else is in your .htaccess file (e.g., pretty-url rules added by wordpress itself):
# WP REST API BLOCK JSON REQUESTS
# Block/Forbid Requests to: /wp-json/wp/
# WP REST API REQUEST METHODS: GET, POST, PUT, PATCH, DELETE
RewriteCond %{REQUEST_METHOD} ^(GET|POST|PUT|PATCH|DELETE) [NC]
RewriteCond %{REQUEST_URI} ^.*wp-json/wp/ [NC]
RewriteRule ^(.*)$ - [F]
A very drastic method, is also to have a 404.html webpage in your root and then add this line:
# WP REST API BLOCK JSON REQUESTS
# Redirect to a 404.html (you may want to add a 404 header!)
RewriteRule ^wp-json.*$ 404.html
Note that, unless you use a static page, i.e., not involved with wordpress functions, if you want to return a 404 error with an appropriate error page, this is a complete separate topic, with a lot of issues when Wordpress is involved

Answer 5

if you want to disable Wordpress REST API completely use this code:
// Disable Wordpress REST API
remove_action( 'init', 'rest_api_init' );
remove_action( 'rest_api_init', 'rest_api_default_filters', 10 );
remove_action( 'rest_api_init', 'register_initial_settings', 10 );
remove_action( 'rest_api_init', 'create_initial_rest_routes', 99 );
remove_action( 'parse_request', 'rest_api_loaded' );

Answer 6

With the plugin "Disable REST API" you can select which APIs you want to enable, e.g. the contact form 7 API. See the plugin's settings (yoursite.com/wp-admin/options-general.php?page=disable_rest_api_settings)

Answer 7

add_filter('rest_enabled', '__return_false');
add_filter('rest_jsonp_enabled', '__return_false');

Answer 8

There are several points you need to "turn off". Also, you might want to place some kind of notice to someone coming to that page...
Here is what I used (and was checked):
function itsme_disable_feed() {
wp_die( __( 'No feed available, please visit the Example!' ) );
}
add_action('do_feed', 'itsme_disable_feed', 1);
add_action('do_feed_rdf', 'itsme_disable_feed', 1);
add_action('do_feed_rss', 'itsme_disable_feed', 1);
add_action('do_feed_rss2', 'itsme_disable_feed', 1);
add_action('do_feed_atom', 'itsme_disable_feed', 1);
add_action('do_feed_rss2_comments', 'itsme_disable_feed', 1);
add_action('do_feed_atom_comments', 'itsme_disable_feed', 1);
As per wp_die() docs:
This function complements the die() PHP function. The difference is
that HTML will be displayed to the user. It is recommended to use this
function only when the execution should not continue any further. It
is not recommended to call this function very often, and try to handle
as many errors as possible silently or more gracefully.
Hope this helps.