const API_HOST = 'rest.akismet.com';
const MAX_DELAY_BEFORE_MODERATION_EMAIL = 86400; // One day in seconds
private static $last_comment = '';
private static $initiated = false;
private static $prevent_moderation_email_for_these_comments = array();
private static $last_comment_result = null;
private static $comment_as_submitted_allowed_keys = array( 'blog' => '', 'blog_charset' => '', 'blog_lang' => '', 'blog_ua' => '', 'comment_agent' => '', 'comment_author' => '', 'comment_author_IP' => '', 'comment_author_email' => '', 'comment_author_url' => '', 'comment_content' => '', 'comment_date_gmt' => '', 'comment_tags' => '', 'comment_type' => '', 'guid' => '', 'is_test' => '', 'permalink' => '', 'reporter' => '', 'site_domain' => '', 'submit_referer' => '', 'submit_uri' => '', 'user_ID' => '', 'user_agent' => '', 'user_id' => '', 'user_ip' => '' );
private static $is_rest_api_call = false;
public static function init() {
if ( ! self::$initiated ) {
* Initializes WordPress hooks
private static function init_hooks() {
add_action( 'wp_insert_comment', array( 'Akismet', 'auto_check_update_meta' ), 10, 2 );
add_filter( 'preprocess_comment', array( 'Akismet', 'auto_check_comment' ), 1 );
add_filter( 'rest_pre_insert_comment', array( 'Akismet', 'rest_auto_check_comment' ), 1 );
add_action( 'akismet_scheduled_delete', array( 'Akismet', 'delete_old_comments' ) );
add_action( 'akismet_scheduled_delete', array( 'Akismet', 'delete_old_comments_meta' ) );
add_action( 'akismet_scheduled_delete', array( 'Akismet', 'delete_orphaned_commentmeta' ) );
add_action( 'akismet_schedule_cron_recheck', array( 'Akismet', 'cron_recheck' ) );
add_action( 'comment_form', array( 'Akismet', 'add_comment_nonce' ), 1 );
add_action( 'admin_head-edit-comments.php', array( 'Akismet', 'load_form_js' ) );
add_action( 'comment_form', array( 'Akismet', 'load_form_js' ) );
add_action( 'comment_form', array( 'Akismet', 'inject_ak_js' ) );
add_filter( 'script_loader_tag', array( 'Akismet', 'set_form_js_async' ), 10, 3 );
add_filter( 'comment_moderation_recipients', array( 'Akismet', 'disable_moderation_emails_if_unreachable' ), 1000, 2 );
add_filter( 'pre_comment_approved', array( 'Akismet', 'last_comment_status' ), 10, 2 );
add_action( 'transition_comment_status', array( 'Akismet', 'transition_comment_status' ), 10, 3 );
// Run this early in the pingback call, before doing a remote fetch of the source uri
add_action( 'xmlrpc_call', array( 'Akismet', 'pre_check_pingback' ) );
add_filter( 'jetpack_options_whitelist', array( 'Akismet', 'add_to_jetpack_options_whitelist' ) );
add_action( 'update_option_wordpress_api_key', array( 'Akismet', 'updated_option' ), 10, 2 );
add_action( 'add_option_wordpress_api_key', array( 'Akismet', 'added_option' ), 10, 2 );
add_action( 'comment_form_after', array( 'Akismet', 'display_comment_form_privacy_notice' ) );
public static function get_api_key() {
return apply_filters( 'akismet_get_api_key', defined('WPCOM_API_KEY') ? constant('WPCOM_API_KEY') : get_option('wordpress_api_key') );
public static function check_key_status( $key, $ip = null ) {
return self::http_post( Akismet::build_query( array( 'key' => $key, 'blog' => get_option( 'home' ) ) ), 'verify-key', $ip );
public static function verify_key( $key, $ip = null ) {
// Shortcut for obviously invalid keys.
if ( strlen( $key ) != 12 ) {
$response = self::check_key_status( $key, $ip );
if ( $response[1] != 'valid' && $response[1] != 'invalid' )
public static function deactivate_key( $key ) {
$response = self::http_post( Akismet::build_query( array( 'key' => $key, 'blog' => get_option( 'home' ) ) ), 'deactivate' );
if ( $response[1] != 'deactivated' )
* Add the akismet option to the Jetpack options management whitelist.
* @param array $options The list of whitelisted option names.
* @return array The updated whitelist
public static function add_to_jetpack_options_whitelist( $options ) {
$options[] = 'wordpress_api_key';
* When the akismet option is updated, run the registration call.
* This should only be run when the option is updated from the Jetpack/WP.com
* API call, and only if the new key is different than the old key.
* @param mixed $old_value The old option value.
* @param mixed $value The new option value.
public static function updated_option( $old_value, $value ) {
if ( ! class_exists( 'WPCOM_JSON_API_Update_Option_Endpoint' ) ) {
// Only run the registration if the old key is different.
if ( $old_value !== $value ) {
self::verify_key( $value );
* Treat the creation of an API key the same as updating the API key to a new value.
* @param mixed $option_name Will always be "wordpress_api_key", until something else hooks in here.
* @param mixed $value The option value.
public static function added_option( $option_name, $value ) {
if ( 'wordpress_api_key' === $option_name ) {
return self::updated_option( '', $value );
public static function rest_auto_check_comment( $commentdata ) {
self::$is_rest_api_call = true;
return self::auto_check_comment( $commentdata );
public static function auto_check_comment( $commentdata ) {
// If no key is configured, then there's no point in doing any of this.
if ( ! self::get_api_key() ) {
self::$last_comment_result = null;
$comment['user_ip'] = self::get_ip_address();
$comment['user_agent'] = self::get_user_agent();
$comment['referrer'] = self::get_referer();
$comment['blog'] = get_option( 'home' );
$comment['blog_lang'] = get_locale();
$comment['blog_charset'] = get_option('blog_charset');
$comment['permalink'] = get_permalink( $comment['comment_post_ID'] );
if ( ! empty( $comment['user_ID'] ) ) {
$comment['user_role'] = Akismet::get_user_roles( $comment['user_ID'] );
/** See filter documentation in init_hooks(). */
$akismet_nonce_option = apply_filters( 'akismet_comment_nonce', get_option( 'akismet_comment_nonce' ) );
$comment['akismet_comment_nonce'] = 'inactive';
if ( $akismet_nonce_option == 'true' || $akismet_nonce_option == '' ) {
$comment['akismet_comment_nonce'] = 'failed';
if ( isset( $_POST['akismet_comment_nonce'] ) && wp_verify_nonce( $_POST['akismet_comment_nonce'], 'akismet_comment_nonce_' . $comment['comment_post_ID'] ) )
$comment['akismet_comment_nonce'] = 'passed';
// comment reply in wp-admin
if ( isset( $_POST['_ajax_nonce-replyto-comment'] ) && check_ajax_referer( 'replyto-comment', '_ajax_nonce-replyto-comment' ) )
$comment['akismet_comment_nonce'] = 'passed';
if ( self::is_test_mode() )
$comment['is_test'] = 'true';
foreach( $_POST as $key => $value ) {
if ( is_string( $value ) )
$comment["POST_{$key}"] = $value;
foreach ( $_SERVER as $key => $value ) {
if ( ! is_string( $value ) ) {
if ( preg_match( "/^HTTP_COOKIE/", $key ) ) {
// Send any potentially useful $_SERVER vars, but avoid sending junk we don't need.
if ( preg_match( "/^(HTTP_|REMOTE_ADDR|REQUEST_URI|DOCUMENT_URI)/", $key ) ) {
$comment[ "$key" ] = $value;
$post = get_post( $comment['comment_post_ID'] );
if ( ! is_null( $post ) ) {
// $post can technically be null, although in the past, it's always been an indicator of another plugin interfering.
$comment[ 'comment_post_modified_gmt' ] = $post->post_modified_gmt;
$response = self::http_post( Akismet::build_query( $comment ), 'comment-check' );
do_action( 'akismet_comment_check_response', $response );
$commentdata['comment_as_submitted'] = array_intersect_key( $comment, self::$comment_as_submitted_allowed_keys );
$commentdata['akismet_result'] = $response[1];
if ( isset( $response[0]['x-akismet-pro-tip'] ) )
$commentdata['akismet_pro_tip'] = $response[0]['x-akismet-pro-tip'];
if ( isset( $response[0]['x-akismet-error'] ) ) {
// An error occurred that we anticipated (like a suspended key) and want the user to act on.
self::$last_comment_result = '0';
else if ( 'true' == $response[1] ) {
// akismet_spam_count will be incremented later by comment_is_spam()
self::$last_comment_result = 'spam';
$discard = ( isset( $commentdata['akismet_pro_tip'] ) && $commentdata['akismet_pro_tip'] === 'discard' && self::allow_discard() );
do_action( 'akismet_spam_caught', $discard );
// The spam is obvious, so we're bailing out early.
// akismet_result_spam() won't be called so bump the counter here
if ( $incr = apply_filters( 'akismet_spam_count_incr', 1 ) ) {
update_option( 'akismet_spam_count', get_option( 'akismet_spam_count' ) + $incr );
if ( self::$is_rest_api_call ) {
return new WP_Error( 'akismet_rest_comment_discarded', __( 'Comment discarded.', 'akismet' ) );
// Redirect back to the previous page, or failing that, the post permalink, or failing that, the homepage of the blog.
$redirect_to = isset( $_SERVER['HTTP_REFERER'] ) ? $_SERVER['HTTP_REFERER'] : ( $post ? get_permalink( $post ) : home_url() );
wp_safe_redirect( esc_url_raw( $redirect_to ) );
else if ( self::$is_rest_api_call ) {
// The way the REST API structures its calls, we can set the comment_approved value right away.
$commentdata['comment_approved'] = 'spam';
// if the response is neither true nor false, hold the comment for moderation and schedule a recheck
if ( 'true' != $response[1] && 'false' != $response[1] ) {
if ( !current_user_can('moderate_comments') ) {
// Comment status should be moderated
self::$last_comment_result = '0';
if ( ! wp_next_scheduled( 'akismet_schedule_cron_recheck' ) ) {
wp_schedule_single_event( time() + 1200, 'akismet_schedule_cron_recheck' );
do_action( 'akismet_scheduled_recheck', 'invalid-response-' . $response[1] );
self::$prevent_moderation_email_for_these_comments[] = $commentdata;
// Delete old comments daily
if ( ! wp_next_scheduled( 'akismet_scheduled_delete' ) ) {
wp_schedule_event( time(), 'daily', 'akismet_scheduled_delete' );
self::set_last_comment( $commentdata );
self::fix_scheduled_recheck();
public static function get_last_comment() {
return self::$last_comment;
public static function set_last_comment( $comment ) {
if ( is_null( $comment ) ) {
self::$last_comment = null;
// We filter it here so that it matches the filtered comment data that we'll have to compare against later.
// wp_filter_comment expects comment_author_IP
self::$last_comment = wp_filter_comment(
array( 'comment_author_IP' => self::get_ip_address() ),
// this fires on wp_insert_comment. we can't update comment_meta when auto_check_comment() runs
// because we don't know the comment ID at that point.
public static function auto_check_update_meta( $id, $comment ) {
// wp_insert_comment() might be called in other contexts, so make sure this is the same comment
// as was checked by auto_check_comment
if ( is_object( $comment ) && !empty( self::$last_comment ) && is_array( self::$last_comment ) ) {
if ( self::matches_last_comment( $comment ) ) {
load_plugin_textdomain( 'akismet' );
// normal result: true or false
if ( self::$last_comment['akismet_result'] == 'true' ) {
update_comment_meta( $comment->comment_ID, 'akismet_result', 'true' );
self::update_comment_history( $comment->comment_ID, '', 'check-spam' );
if ( $comment->comment_approved != 'spam' )
self::update_comment_history(
'status-changed-'.$comment->comment_approved
elseif ( self::$last_comment['akismet_result'] == 'false' ) {
update_comment_meta( $comment->comment_ID, 'akismet_result', 'false' );
self::update_comment_history( $comment->comment_ID, '', 'check-ham' );
// Status could be spam or trash, depending on the WP version and whether this change applies:
// https://core.trac.wordpress.org/changeset/34726
if ( $comment->comment_approved == 'spam' || $comment->comment_approved == 'trash' ) {
if ( wp_blacklist_check($comment->comment_author, $comment->comment_author_email, $comment->comment_author_url, $comment->comment_content, $comment->comment_author_IP, $comment->comment_agent) )
self::update_comment_history( $comment->comment_ID, '', 'wp-blacklisted' );
self::update_comment_history( $comment->comment_ID, '', 'status-changed-'.$comment->comment_approved );
} // abnormal result: error
update_comment_meta( $comment->comment_ID, 'akismet_error', time() );
self::update_comment_history(
array( 'response' => substr( self::$last_comment['akismet_result'], 0, 50 ) )
// record the complete original data as submitted for checking
if ( isset( self::$last_comment['comment_as_submitted'] ) )
update_comment_meta( $comment->comment_ID, 'akismet_as_submitted', self::$last_comment['comment_as_submitted'] );
if ( isset( self::$last_comment['akismet_pro_tip'] ) )
update_comment_meta( $comment->comment_ID, 'akismet_pro_tip', self::$last_comment['akismet_pro_tip'] );
public static function delete_old_comments() {
* Determines how many comments will be deleted in each batch.
* @param int The default, as defined by AKISMET_DELETE_LIMIT.
$delete_limit = apply_filters( 'akismet_delete_comment_limit', defined( 'AKISMET_DELETE_LIMIT' ) ? AKISMET_DELETE_LIMIT : 10000 );
$delete_limit = max( 1, intval( $delete_limit ) );
* Determines how many days a comment will be left in the Spam queue before being deleted.
* @param int The default number of days.
$delete_interval = apply_filters( 'akismet_delete_comment_interval', 15 );
$delete_interval = max( 1, intval( $delete_interval ) );
while ( $comment_ids = $wpdb->get_col( $wpdb->prepare( "SELECT comment_id FROM {$wpdb->comments} WHERE DATE_SUB(NOW(), INTERVAL %d DAY) > comment_date_gmt AND comment_approved = 'spam' LIMIT %d", $delete_interval, $delete_limit ) ) ) {
if ( empty( $comment_ids ) )
$wpdb->queries = array();
foreach ( $comment_ids as $comment_id ) {
do_action( 'delete_comment', $comment_id );
do_action( 'akismet_batch_delete_count', __FUNCTION__ );
// Prepared as strings since comment_id is an unsigned BIGINT, and using %d will constrain the value to the maximum signed BIGINT.
$format_string = implode( ", ", array_fill( 0, count( $comment_ids ), '%s' ) );
$wpdb->query( $wpdb->prepare( "DELETE FROM {$wpdb->comments} WHERE comment_id IN ( " . $format_string . " )", $comment_ids ) );
$wpdb->query( $wpdb->prepare( "DELETE FROM {$wpdb->commentmeta} WHERE comment_id IN ( " . $format_string . " )", $comment_ids ) );
clean_comment_cache( $comment_ids );
do_action( 'akismet_delete_comment_batch', count( $comment_ids ) );
if ( apply_filters( 'akismet_optimize_table', ( mt_rand(1, 5000) == 11), $wpdb->comments ) ) // lucky number
$wpdb->query("OPTIMIZE TABLE {$wpdb->comments}");
public static function delete_old_comments_meta() {
$interval = apply_filters( 'akismet_delete_commentmeta_interval', 15 );
# enforce a minimum of 1 day
$interval = absint( $interval );
// akismet_as_submitted meta values are large, so expire them
// after $interval days regardless of the comment status
while ( $comment_ids = $wpdb->get_col( $wpdb->prepare( "SELECT m.comment_id FROM {$wpdb->commentmeta} as m INNER JOIN {$wpdb->comments} as c USING(comment_id) WHERE m.meta_key = 'akismet_as_submitted' AND DATE_SUB(NOW(), INTERVAL %d DAY) > c.comment_date_gmt LIMIT 10000", $interval ) ) ) {
if ( empty( $comment_ids ) )
$wpdb->queries = array();
foreach ( $comment_ids as $comment_id ) {
delete_comment_meta( $comment_id, 'akismet_as_submitted' );
do_action( 'akismet_batch_delete_count', __FUNCTION__ );
do_action( 'akismet_delete_commentmeta_batch', count( $comment_ids ) );
if ( apply_filters( 'akismet_optimize_table', ( mt_rand(1, 5000) == 11), $wpdb->commentmeta ) ) // lucky number
$wpdb->query("OPTIMIZE TABLE {$wpdb->commentmeta}");
// Clear out comments meta that no longer have corresponding comments in the database
public static function delete_orphaned_commentmeta() {
$start_time = isset( $_SERVER['REQUEST_TIME_FLOAT'] ) ? $_SERVER['REQUEST_TIME_FLOAT'] : microtime( true );
$max_exec_time = max( ini_get('max_execution_time') - 5, 3 );
while ( $commentmeta_results = $wpdb->get_results( $wpdb->prepare( "SELECT m.meta_id, m.comment_id, m.meta_key FROM {$wpdb->commentmeta} as m LEFT JOIN {$wpdb->comments} as c USING(comment_id) WHERE c.comment_id IS NULL AND m.meta_id > %d ORDER BY m.meta_id LIMIT 1000", $last_meta_id ) ) ) {
if ( empty( $commentmeta_results ) )
$wpdb->queries = array();
$commentmeta_deleted = 0;
foreach ( $commentmeta_results as $commentmeta ) {
if ( 'akismet_' == substr( $commentmeta->meta_key, 0, 8 ) ) {
delete_comment_meta( $commentmeta->comment_id, $commentmeta->meta_key );
do_action( 'akismet_batch_delete_count', __FUNCTION__ );
$last_meta_id = $commentmeta->meta_id;
do_action( 'akismet_delete_commentmeta_batch', $commentmeta_deleted );
// If we're getting close to max_execution_time, quit for this round.
if ( microtime(true) - $start_time > $max_exec_time )
if ( apply_filters( 'akismet_optimize_table', ( mt_rand(1, 5000) == 11), $wpdb->commentmeta ) ) // lucky number
$wpdb->query("OPTIMIZE TABLE {$wpdb->commentmeta}");
// how many approved comments does this author have?
public static function get_user_comments_approved( $user_id, $comment_author_email, $comment_author, $comment_author_url ) {
if ( !empty( $user_id ) )
return (int) $wpdb->get_var( $wpdb->prepare( "SELECT COUNT(*) FROM {$wpdb->comments} WHERE user_id = %d AND comment_approved = 1", $user_id ) );
if ( !empty( $comment_author_email ) )
return (int) $wpdb->get_var( $wpdb->prepare( "SELECT COUNT(*) FROM {$wpdb->comments} WHERE comment_author_email = %s AND comment_author = %s AND comment_author_url = %s AND comment_approved = 1", $comment_author_email, $comment_author, $comment_author_url ) );
// get the full comment history for a given comment, as an array in reverse chronological order
public static function get_comment_history( $comment_id ) {
$history = get_comment_meta( $comment_id, 'akismet_history', false );
if ( empty( $history ) || empty( $history[ 0 ] ) ) {
// To see all variants when testing.
$history[] = array( 'time' => 445856401, 'message' => 'Old versions of Akismet stored the message as a literal string in the commentmeta.', 'event' => null );
$history[] = array( 'time' => 445856402, 'event' => 'recheck-spam' );
$history[] = array( 'time' => 445856403, 'event' => 'check-spam' );
$history[] = array( 'time' => 445856404, 'event' => 'recheck-ham' );
$history[] = array( 'time' => 445856405, 'event' => 'check-ham' );
$history[] = array( 'time' => 445856406, 'event' => 'wp-blacklisted' );
$history[] = array( 'time' => 445856407, 'event' => 'report-spam' );
$history[] = array( 'time' => 445856408, 'event' => 'report-spam', 'user' => 'sam' );
$history[] = array( 'message' => 'sam reported this comment as spam (hardcoded message).', 'time' => 445856400, 'event' => 'report-spam', 'user' => 'sam' );
$history[] = array( 'time' => 445856409, 'event' => 'report-ham', 'user' => 'sam' );
$history[] = array( 'message' => 'sam reported this comment as ham (hardcoded message).', 'time' => 445856400, 'event' => 'report-ham', 'user' => 'sam' ); //
$history[] = array( 'time' => 445856410, 'event' => 'cron-retry-spam' );
$history[] = array( 'time' => 445856411, 'event' => 'cron-retry-ham' );
$history[] = array( 'time' => 445856412, 'event' => 'check-error' ); //
$history[] = array( 'time' => 445856413, 'event' => 'check-error', 'meta' => array( 'response' => 'The server was taking a nap.' ) );
$history[] = array( 'time' => 445856414, 'event' => 'recheck-error' ); // Should not generate a message.
$history[] = array( 'time' => 445856415, 'event' => 'recheck-error', 'meta' => array( 'response' => 'The server was taking a nap.' ) );