Hooks

Everything the plugin exposes. All names are prefixed happy_comments_.

Form and subscription

Filter	Purpose
happy_comments_show_comment_form_field	bool $enabled, int $post_id — hide the checkbox, per post
happy_comments_comment_form_label	string $label — the checkbox text
happy_comments_comment_form_precheck	bool $checked — whether it starts ticked
happy_comments_subscription_scope	string $scope — all or replies
happy_comments_comment_form_field	string $html, bool $checked, int $post_id — the whole field markup
happy_comments_subscribe_form	string $html, int $post_id — the standalone form markup
happy_comments_subscribe_form_available	bool $available, int $post_id — defaults to comments_open()
happy_comments_subscribe_response	string $message — shown after any submission. Keep it outcome-independent
happy_comments_moderation_note	string $note — the sentence added to the moderation notice. Empty removes it

Email

Filter	Purpose
happy_comments_mail_subject	string $subject, string $type, array $vars
happy_comments_mail_body_html	string $body, string $type, array $vars
happy_comments_mail_body_text	string $body, string $type, array $vars
happy_comments_mail_headers	array $headers, string $type, array $vars
happy_comments_from_name	string $name — defaults to the site name
happy_comments_from_address	string $address — defaults to wordpress@yourdomain
happy_comments_unsubscribe_mailto	string $address, int $subscription_id — off by default
happy_comments_confirmation_lifetime	int $seconds — default 172800 (48 hours)
happy_comments_send_after_response	bool $can_send — send at the end of the request rather than by cron

$type is confirmation or notification.

Setting a mailto: unsubscribe target is a promise that somebody reads that mailbox and acts on it. If nobody does, a reader who clicks unsubscribe in Apple Mail believes they have opted out while staying subscribed. Only enable it if monitoring that mailbox is a process rather than an intention.

Sending and cleanup

Filter	Purpose
happy_comments_notify_whole_subthread	bool $whole — true notifies on the whole subthread, false on direct replies only
happy_comments_max_comment_age	int $seconds — older comments are treated as imported. Default 86400
happy_comments_request_limit	int $limit — comments queued per request. Default 100
happy_comments_retention_days	int $days — how long unconfirmed rows are kept
happy_comments_throttle_limit	int $value, string $name — min_interval, max_age, ip_limit, address_cooldown

Consent and privacy

Filter	Purpose
happy_comments_consent_ip	string $truncated, string $full — return $full to store the whole address, '' to store none
happy_comments_privacy_url	string $url
happy_comments_privacy_label	string $label

Admin

Filter	Purpose
happy_comments_admin_capability	string $capability — defaults to manage_options
happy_comments_endpoint_page	string $body, string $title — the confirm and unsubscribe pages

The capability is manage_options rather than moderate_comments on purpose. Comment moderation is often delegated to editors, and this screen lists every subscriber's address alongside their consent record.

Actions

Action	Fires
happy_comments_init	once the plugin has registered its hooks
happy_comments_activate	on activation
happy_comments_deactivate	on deactivation
happy_comments_unsubscribed	int $id — after an unsubscribe
happy_comments_status_changed	int $id, string $new, string $previous
happy_comments_deleted_subscriptions	array $ids, int $deleted
happy_comments_confirmation_failed	int $id — wp_mail() refused the message
happy_comments_purged_unconfirmed	int $deleted, string $cutoff
happy_comments_purged_post	int $post_id, int $deleted

Examples

Send from an address your provider has verified:

add_filter( 'happy_comments_from_address', fn() => 'hello@example.com' );
add_filter( 'happy_comments_from_name',    fn() => 'Example' );

Notify only on direct replies:

add_filter( 'happy_comments_notify_whole_subthread', '__return_false' );

Store no IP addresses at all:

add_filter( 'happy_comments_consent_ip', '__return_empty_string' );

Log confirmations that could not be sent:

add_action( 'happy_comments_confirmation_failed', function ( $id ) {
	error_log( 'Happy Comments: confirmation ' . $id . ' failed to send' );
} );