Developer Hooks & Reference

A concise reference of the plugin’s extension points and data contract. For the narrative design of how the pieces fit together, read Architecture first.

The plugin is intentionally small, so the customization surface is small too. Right now there are two filters, a code-level hook list you can extend, and a stable data contract (meta keys, options, AJAX endpoint, and table) that other code can rely on.

Filters

These are the only apply_filters() extension points in the plugin today. Both control the per-IP rate limiter on the public signup endpoint.

sscs_rate_limit_max

Maximum number of signup submissions allowed per IP address within the window.

• Type: int
• Default: 5

add_filter( 'sscs_rate_limit_max', function () {
    return 10;
} );

sscs_rate_limit_window

Length of the rate-limit window, in seconds.

• Type: int (seconds)
• Default: 600 (10 * MINUTE_IN_SECONDS)

add_filter( 'sscs_rate_limit_window', function () {
    return 30 * MINUTE_IN_SECONDS;
} );

See Spam & Abuse Protection for how the limiter behaves.

Code-level extension points

Theme hook locations ($known_locations)

The plugin replaces WooCommerce’s add-to-cart output by finding where woocommerce_template_single_add_to_cart is hooked. It checks a fast list of known locations first, then falls back to scanning every registered hook. If your theme uses a non-standard hook and you want to skip the scan, add it to the $known_locations array in sscs_maybe_replace_add_to_cart() (super-speedy-coming-soon.php):

$known_locations = array(
    array( 'woocommerce_single_product_summary', 30 ), // WooCommerce default
    array( 'your_theme_custom_hook', 10 ),              // your theme
);

This is a source edit, not a filter — see “Known limitations” below.

Data contract

These names are stable and safe for other code (exports, migrations, integrations) to depend on.

Post meta (per product)

Meta key	Type	Meaning
_sscs_coming_soon	'yes' / 'no'	Master switch for the coming soon display.
_sscs_arrival_date	YYYY-MM-DD string	Countdown target date.
_sscs_offer_description	HTML (wp_kses_post)	Promo text shown above the form.
_sscs_email_provider	mailerlite / sse	Which provider collects signups.
_sscs_mailerlite_group_id	string	MailerLite group for this product.
_sscs_sse_form_id	int	SSE form ID (when provider is sse).

Options (global)

Option	Default	Meaning
sscs_mailerlite_api_key	''	MailerLite API key.
sscs_honeypot_enabled	'yes'	Honeypot toggle.
sscs_captcha_enabled	'no'	Turnstile toggle.
sscs_turnstile_site_key	''	Turnstile public key.
sscs_turnstile_secret_key	''	Turnstile secret key.

Database table — {$wpdb->prefix}sscs_signups

Column	Type	Notes
id	BIGINT UNSIGNED	PK, auto-increment.
email	VARCHAR(255)	UNIQUE.
mailerlite_id	VARCHAR(255)	Subscriber ID from MailerLite.
referrer_id	VARCHAR(255)	Referring subscriber’s MailerLite ID.
wp_user_id	BIGINT UNSIGNED	Logged-in user, if any.
created_at	TIMESTAMP	Defaults to now.

Created on activation via register_activation_hook → sscs_create_custom_table().

AJAX endpoint

• Action: sscs_ajax_signup (registered for both wp_ajax_ and wp_ajax_nopriv_).
• Nonce: action sscs_signup_nonce, sent in the nonce POST field.
• Expected POST fields: email, post_id, name (honeypot — must be empty), shared_by (optional referral ID), cf_token (Turnstile token, when enabled).
• Response: wp_send_json_success/wp_send_json_error with a message; the success payload also includes mailerlite_id.

The nonce is served to logged-out visitors via wp_localize_script, so it is not an abuse control on this public endpoint — the honeypot, rate limit, and optional CAPTCHA are. Don’t rely on the nonce for security here.

Helper functions

Useful predicates if you’re extending behaviour:

• sscs_honeypot_enabled(): bool
• sscs_captcha_enabled(): bool — true only when the toggle is on and both Turnstile keys are set.
• sscs_check_rate_limit(): bool — false when the caller is over the limit.
• sscs_verify_turnstile(): bool
• sscs_add_subscriber_to_mailerlite( string $email, string $group_id ): string — returns the MailerLite subscriber ID (or '').

Localized JS object (sscs_ajax)

Available on coming soon product pages: ajax_url, nonce, post_id, arrival_date, captcha (1/0).

Known limitations / extension requests

These are deliberate notes for future work — extension points that would be useful but do not exist yet:

• No template-override filter. sscs_render_coming_soon_template() includes templates/sscs-coming-soon-template.php directly from the plugin folder, with no locate_template() lookup or filter on the path. Themes can’t override the markup without editing the plugin. A sscs_template_path filter (or a locate_template() fallback) would fix this.
• No action hooks. There are no custom do_action() points (e.g. around a successful signup), so you can’t currently fire your own code after a signup without intercepting the AJAX action. A do_action( 'sscs_after_signup', $email, $product_id, $mailerlite_id ) would be a natural addition.
• No template override for the SSE branch beyond what SSE itself provides.

If you need any of these, they’re tracked as candidate enhancements.

Related

• Architecture — how these pieces fit together.
• Spam & Abuse Protection — the rate-limit filters in context.