Hooks & Filters

The ecosystem exposes over 150 hooks and filters for extending the plugin, theme, and modules — roughly 90 in the plugin (wpec_*) and 65 in the theme (flavor_*). They follow standard WordPress add_action() / add_filter() semantics, so anything you already know about the WordPress plugin API applies here.

Surface	Actions	Filters	Total
Plugin (wpec_*)	~63	~30	~93
Theme (flavor_*)	~50	~16	~66

How Hooks Work

Just like WordPress core, you attach callbacks to actions and filters:

// Action — do something when an event occurs
add_action('wpec_order_created', function ($order, $checkout) {
    my_crm_sync($order);
}, 10, 2);

// Filter — modify data before it's used
add_filter('wpec_product_price', function ($price, $product) {
    return $price * 0.9; // 10% discount
}, 10, 2);

Naming Conventions

Prefix	Source	Example
wpec_	WP eCommerce Core Plugin	wpec_order_created
flavor_	Flavor Starter Theme	flavor_cart_totals

Plugin Hooks (wpec_*)

~90 hooks covering:

• Lifecycle — initialization, service registration, activation/deactivation
• Products & Variants — before/after save, delete, query, API response, variant save/delete (with a veto point)
• Shop / Search — sort options, products per page, search results, category response
• Cart — item added/updated/removed, cart cleared, price modification, calculated totals
• Checkout & Orders — order creation, status/payment/fulfillment changes, order number prefix, payment/shipping method filtering, order meta
• Customers — created/updated/deleted (drive CRM sync)
• Payments — gateway registration, payment processed/completed/failed, refunds, gateway logging
• Shipping — cost modification, method filtering, tracking URLs
• Inventory / WMS & Warehouses — stock changes, low-stock alerts, warehouse create/update/delete/activate
• Purchasing — purchase orders sent, goods received, supplier-price changes
• Invoicing — invoice issued
• ERP integration listeners — product-cost recompute, ERP-user removal, inventory backfill tuning
• HR — leave requested/approved/rejected
• Reviews — review created/approved
• Marketplace — order created/updated/accepted/rejected/ready
• Email — subject, content, recipients, headers, HTML, template data
• Licensing — feature-gate override (filter) + a read-only gate-check observability action

See Plugin Hooks Reference for the complete list with parameters.

Theme Hooks (flavor_*)

~65 hooks covering:

• Layout — header (before/start/end/after), content wrapper (before/after), footer (before/start/widgets/social/end/after)
• eCommerce Pages — shop, single product, categories, cart, checkout, order received, my account
• Lifecycle — initialization, service registration, translation registration, module registration (Module System 2.0)
• Page Builder — dynamic-tag registration, supported post types
• Module hooks — Stock Alerts, Request Quote, PDF Invoices, Points & Rewards, Newsletter, Abandoned Cart, Contact Form, Product Bundles, Header/Footer Builder
• Filters — initial React state, cart totals, popular search terms, placeholder images, builder/editor post types, content width, smart asset rules, marketing consent, AI image host allowlist, and more

See Theme Hooks Reference for the complete list.

AI agent extensibility is not a hook

The Flavor AI agent surface (Abilities exposed over the flavor-mcp MCP server) is not built on do_action/apply_filters. Abilities are registered by extending an ability base class and calling wp_register_ability() (WordPress Abilities API). Only the theme's AI content helper exposes a hook — the flavor_ai_image_download_hosts filter (host allowlist). Everything else in the AI layer is a class-extension model documented separately, not on this page.

Where to Place Hook Code

• Custom plugin (recommended): Create a simple plugin in wp-content/plugins/my-customizations/
• Child theme functions.php (quick testing): Add to a child theme's functions.php
• mu-plugins (must-use): Place in wp-content/mu-plugins/ for always-active code

<?php
/**
 * Plugin Name: My Store Customizations
 * Description: Custom hooks and filters for my store
 */

// Modify cart totals
add_filter('flavor_cart_totals', function($totals, $cart) {
    $totals['custom_fee'] = 5.00;
    $totals['total'] += 5.00;
    return $totals;
}, 10, 2);

// React to stock changes
add_action('wpec_stock_changed', function($productId, $variantId, $warehouseId, $movement) {
    external_inventory_sync($productId, $movement);
}, 10, 4);

Common Patterns

Price Modification

// B2B pricing: 20% discount for wholesale customers
add_filter('wpec_product_price', function($price, $product) {
    if (current_user_can('wholesale_customer')) {
        return $price * 0.80;
    }
    return $price;
}, 10, 2);

Custom Order Metadata

add_filter('wpec_checkout_order_meta', function($meta, $checkout) {
    if (isset($_COOKIE['referral_code'])) {
        $meta['referral_code'] = sanitize_text_field($_COOKIE['referral_code']);
    }
    return $meta;
}, 10, 2);

API Response Enhancement

add_filter('wpec_api_product_response', function($response, $product) {
    $response['estimated_delivery'] = calculate_delivery_date($product->getId());
    return $response;
}, 10, 2);

React State Injection

add_filter('flavor_initial_state', function($state) {
    $state['myPlugin'] = [
        'apiUrl'   => rest_url('my-plugin/v1/'),
        'settings' => get_my_plugin_settings(),
    ];
    return $state;
});

Registering Translatable Strings

The theme ships its own translation registry (independent of WordPress i18n). To add strings from an extension, hook the flavor_register_translations action and register through Flavor_Translation_Registry, then read them with flavor_t() / flavor_te():

add_action('flavor_register_translations', function() {
    Flavor_Translation_Registry::registerMany([
        'my_plugin.welcome' => 'Welcome to our store',
        'my_plugin.cta'     => 'Shop now',
    ]);
});

// Read anywhere after strings are registered:
echo flavor_t('my_plugin.welcome');   // returns the (possibly translated) string
flavor_te('my_plugin.cta');           // echoes it, HTML-escaped

caution

There is no flavor_register_string()

Use Flavor_Translation_Registry::register($key, $default) (single) or ::registerMany([...]) (batch) — there is no flavor_register_string() function. See the Theme Hooks Reference for details.

Versioning

• New hooks are added in minor versions (x.Y.0)
• Existing hooks are never removed without a major version bump (X.0.0)
• Hook parameter changes are documented in the changelog

Coverage Summary

Area	Actions	Filters	Status
Plugin Lifecycle	5	0	Stable
Products & Variants	8	8	Stable
Shop / Search / Category	0	4	Stable
Cart	4	2	Stable
Checkout & Orders	9	4	Stable
Customers	4	0	Stable
Payments	6	0	Stable
Shipping	0	3	Stable
Inventory / WMS	2	1	Stable
Warehouses	6	0	Stable
Purchasing	3	1	Stable
Invoicing	1	0	Stable
ERP Integration	2	0	Stable
HR	3	0	Stable
Reviews	2	0	Stable
Marketplace	5	0	Stable
Email	2	6	Stable
Licensing	1	1	Stable
Theme Layout	13	0	Stable
Theme eCommerce Pages	18	0	Stable
Theme Lifecycle	5	0	Stable
Theme Page Builder	1	2	Stable
Theme Modules	13	5	Stable
Theme Core Filters	0	9	Stable