wp_ajax_add_user

function wp_ajax_add_user( $action ) {
	if ( empty( $action ) ) {
		$action = 'add-user';
	}

	check_ajax_referer( $action );

	if ( ! current_user_can( 'create_users' ) ) {
		wp_die( -1 );
	}

	$user_id = edit_user();

	if ( ! $user_id ) {
		wp_die( 0 );
	} elseif ( is_wp_error( $user_id ) ) {
		$x = new WP_Ajax_Response(
			array(
				'what' => 'user',
				'id'   => $user_id,
			)
		);
		$x->send();
	}

	$user_object   = get_userdata( $user_id );
	$wp_list_table = _get_list_table( 'WP_Users_List_Table' );

	$role = current( $user_object->roles );

	$x = new WP_Ajax_Response(
		array(
			'what'         => 'user',
			'id'           => $user_id,
			'data'         => $wp_list_table->single_row( $user_object, '', $role ),
			'supplemental' => array(
				'show-link' => sprintf(
					/* translators: %s: The new user. */
					__( 'User %s added' ),
					'<a href="#user-' . $user_id . '">' . $user_object->user_login . '</a>'
				),
				'role'      => $role,
			),
		)
	);
	$x->send();
}