Cookie authentication is the standard authentication method included with
WordPress. When you log in to your dashboard, this sets up the cookies correctly
for you, so plugin and theme developers need only to have a logged-in user.

However, the REST API includes a technique called nonces to avoid CSRF issues.
This prevents other sites from forcing you to perform actions without explicitly
intending to do so. This requires slightly special handling for the API.

For developers using the built-in Javascript API, this is handled automatically
for you. This is the recommended way to use the API for plugins and themes.
Custom data models can extend wp.api.models.Base to ensure this is sent
correctly for any custom requests.

For developers making manual Ajax requests, the nonce will need to be passed
with each request. The API uses nonces with the action set to wp_rest. These
can then be passed to the API via the _wpnonce data parameter (either POST
data or in the query for GET requests), or via the X-WP-Nonce header.

Note: Until recently, most software had spotty support for DELETE requests. For
instance, PHP doesn’t transform the request body of a DELETE request into a super
global. As such, supplying the nonce as a header is the most reliable approach.

It is important to keep in mind that this authentication method relies on WordPress
cookies. As a result this method is only applicable when the REST API is used inside
of WordPress and the current user is logged in. In addition, the current user must
have the appropriate capability to perform the action being performed.

As an example, this is how the built-in Javascript client creates the nonce:

wp_localize_script( 'wp-api', 'wpApiSettings', array(
    'root' => esc_url_raw( rest_url() ),
    'nonce' => wp_create_nonce( 'wp_rest' )
) );

This is then used in the base model:

options.beforeSend = function(xhr) {
  xhr.setRequestHeader('X-WP-Nonce', wpApiSettings.nonce);

  if (beforeSend) {
    return beforeSend.apply(this, arguments);

Here is an example of editing the title of a post, using jQuery AJAX:

$.ajax( {
    url: wpApiSettings.root + 'wp/v2/posts/1',
    method: 'POST',
    beforeSend: function ( xhr ) {
        xhr.setRequestHeader( 'X-WP-Nonce', wpApiSettings.nonce );
        'title' : 'Hello Moon'
} ).done( function ( response ) {
    console.log( response );
} );

Top ↑

Authentication Plugins Authentication Plugins

While cookie authentication is the only authentication mechanism available natively within WordPress, plugins may be added to support alternative modes of authentication that will work from remote applications.   Some example plugins are OAuth 1.0a Server, Application Passwords, and JSON Web Tokens.