Hooks & Filters

WooCommerce Appointments provides a comprehensive set of hooks and filters that allow you to customize and extend the plugin's functionality. This reference includes all available hooks with their parameters, descriptions, and usage examples.

Actions

Actions are events that fire at specific points in the plugin's execution. You can hook into these actions to perform custom functionality.

Appointment Lifecycle

`woocommerce_new_appointment`

Fires when a new appointment is created and saved to the database.

Parameters:

$appointment_id (int) - The appointment ID

Since: 3.0.0

Example:

add_action( 'woocommerce_new_appointment', function( $appointment_id ) {
    $appointment = wc_appointment( $appointment_id );
    // Send custom notification
    wp_mail( 'admin@example.com', 'New Appointment', 'Appointment #' . $appointment_id . ' created' );
} );

`woocommerce_appointment_status_changed`

Fires when an appointment status changes.

Parameters:

$from (string) - Previous status
$to (string) - New (current) status
$appointment_id (int) - The appointment ID
$appointment (WC_Appointment) - The appointment object

Since: 4.11.3

Example:

add_action( 'woocommerce_appointment_status_changed', function( $from, $to, $appointment_id, $appointment ) {
    if ( 'confirmed' === $to ) {
        // Log status change
        error_log( "Appointment #{$appointment_id} changed from {$from} to {$to}" );
    }
}, 10, 4 );

`woocommerce_appointment_{status}`

Dynamic hook that fires when an appointment reaches a specific status. Replace {status} with the actual status (e.g., unpaid, pending-confirmation, confirmed, paid, cancelled, complete, in-cart, was-in-cart).

Parameters:

$appointment_id (int) - The appointment ID
$appointment (WC_Appointment) - The appointment object

Since: 3.0.0

Example:

add_action( 'woocommerce_appointment_confirmed', function( $appointment_id, $appointment ) {
    // Trigger custom action when appointment is confirmed
    do_action( 'my_custom_confirmed_action', $appointment_id );
}, 10, 2 );

`woocommerce_appointment_{old_status}_to_{new_status}`

Dynamic hook for specific status transitions. Fires when an appointment transitions from one status to another.

Parameters:

$appointment_id (int) - The appointment ID
$appointment (WC_Appointment) - The appointment object

Since: 3.0.0

Example:

add_action( 'woocommerce_appointment_pending-confirmation_to_confirmed', function( $appointment_id, $appointment ) {
    // Custom logic when appointment moves from pending to confirmed
}, 10, 2 );

`woocommerce_appointment_cancelled`

Fires when an appointment is cancelled.

Parameters:

$appointment_id (int) - The appointment ID
$appointment (WC_Appointment) - The appointment object

Since: 3.0.0

Example:

add_action( 'woocommerce_appointment_cancelled', function( $appointment_id, $appointment ) {
    // Release resources or send cancellation notification
}, 10, 2 );

`woocommerce_appointment_staff_changed`

Fires when appointment staff changes.

Parameters:

$from (int) - Previous staff ID
$to (int) - New staff ID
$appointment_id (int) - The appointment ID
$appointment (WC_Appointment) - The appointment object

Since: 4.22.0

Example:

add_action( 'woocommerce_appointment_staff_changed', function( $from, $to, $appointment_id, $appointment ) {
    // Notify new staff member
    $staff = get_user_by( 'id', $to );
    if ( $staff ) {
        wp_mail( $staff->user_email, 'New Assignment', 'You have been assigned to appointment #' . $appointment_id );
    }
}, 10, 4 );

`woocommerce_appointments_rescheduled_appointment`

Fires after an appointment is rescheduled.

Parameters:

$appointment_id (int) - The appointment ID
$prev_start_date (int) - Previous start date timestamp
$prev_end_date (int) - Previous end date timestamp

Since: 3.0.0

Example:

add_action( 'woocommerce_appointments_rescheduled_appointment', function( $appointment_id, $prev_start_date, $prev_end_date ) {
    $appointment = wc_appointment( $appointment_id );
    error_log( sprintf(
        'Appointment #%d rescheduled from %s to %s',
        $appointment_id,
        date( 'Y-m-d H:i', $prev_start_date ),
        date( 'Y-m-d H:i', $appointment->get_start() )
    ) );
}, 10, 3 );

`woocommerce_appointments_cancelled_appointment`

Fires when a customer cancels an appointment.

Parameters:

$appointment_id (int) - The appointment ID

Since: 3.0.0

Example:

add_action( 'woocommerce_appointments_cancelled_appointment', function( $appointment_id ) {
    // Process refund or update external system
    // Note: This example assumes you have an external system integration
    // (e.g., CRM, accounting software, or custom API)
}, 10, 1 );

External Service Required

This example assumes integration with an external system (CRM, accounting software, custom API, etc.). You'll need to implement the connection logic based on your specific service.

`woocommerce_new_appointment_order`

Fires when a new order is created for an appointment.

Parameters:

$order_id (int) - The order ID

Since: 3.0.0

Example:

add_action( 'woocommerce_new_appointment_order', function( $order_id ) {
    $order = wc_get_order( $order_id );
    // Custom order processing
}, 10, 1 );

Admin Interface

`woocommerce_appointments_after_staff_cost`

Fires after staff cost field in admin.

Parameters:

$staff (WC_Appointment_Staff) - The staff object
$post_id (int) - The product/post ID

Since: 3.0.0

Example:

add_action( 'woocommerce_appointments_after_staff_cost', function( $staff, $post_id ) {
    // Add custom field after staff cost
    echo '<input type="text" name="custom_staff_field[' . $staff->get_id() . ']" />';
}, 10, 2 );

`woocommerce_appointments_after_staff_qty`

Fires after staff quantity field in admin.

Parameters:

$staff (WC_Appointment_Staff) - The staff object
$post_id (int) - The product/post ID

Since: 3.0.0

Google Calendar Integration

`woocommerce_appointments_sync_from_gcal_event_start`

Fires before processing a Google Calendar event during sync.

Parameters:

$event (object) - The Google Calendar event object

Since: 3.0.0

Example:

add_action( 'woocommerce_appointments_sync_from_gcal_event_start', function( $event ) {
    // Log or modify event before processing
    error_log( 'Syncing event: ' . $event->summary );
}, 10, 1 );

Indexing & Performance

`wc_appointments_index_availability_rule`

Fires when indexing an availability rule.

Parameters:

$rule_id (int) - The availability rule ID

Since: 3.0.0

`wc_appointments_index_appointment`

Fires when indexing an appointment.

Parameters:

$appointment_id (int) - The appointment ID

Since: 3.0.0

Filters

Filters allow you to modify data before it's used or displayed. Always return the modified value.

Availability & Scheduling

`woocommerce_appointments_get_posted_data`

Filters posted appointment form data before processing.

Parameters:

$data (array) - The appointment data array
$product (WC_Product_Appointment) - The product object
$posted (array) - The posted form data

Returns: (array) Modified appointment data

Since: 3.0.0

Example:

add_filter( 'woocommerce_appointments_get_posted_data', function( $data, $product, $posted ) {
    // Add custom field to appointment data
    if ( isset( $posted['custom_field'] ) ) {
        $data['custom_field'] = sanitize_text_field( $posted['custom_field'] );
    }
    return $data;
}, 10, 3 );

`woocommerce_appointments_get_available_quantity`

Filters available quantity for a product.

Parameters:

$qty (int) - Available quantity
$product (WC_Product_Appointment) - The product object
$staff_id (int|null) - Staff ID (null if no staff)

Returns: (int) Modified quantity

Since: 3.0.0

Example:

add_filter( 'woocommerce_appointments_get_available_quantity', function( $qty, $product, $staff_id ) {
    // Limit quantity based on custom logic
    if ( $staff_id && $staff_id === 5 ) {
        return min( $qty, 2 ); // Max 2 for this staff member
    }
    return $qty;
}, 10, 3 );

`woocommerce_appointments_time_slots`

Filters all time slots for availability calculation.

Parameters:

$available_slots (array) - Available slots array
$slots (array) - All slots array
$intervals (array) - Time intervals
$time_to_check (int) - Timestamp to check
$staff_id (int) - Staff ID
$from (int) - Start timestamp
$to (int) - End timestamp
$timezone (string) - Timezone string
$product (WC_Product_Appointment) - The product object

Returns: (array) Modified available slots

Since: 3.0.0

`woocommerce_appointments_time_slot_html`

Filters HTML for a single time slot display.

Parameters:

$slot_html (string) - The slot HTML
$display_slot (int) - Display slot timestamp
$quantity (array) - Quantity array
$time_to_check (int) - Timestamp to check
$staff_id (int) - Staff ID
$timezone (string) - Timezone string
$product (WC_Product_Appointment) - The product object
$spaces_left (int) - Spaces remaining
$args (array) - Additional arguments

Returns: (string) Modified HTML

Since: 3.0.0

Example:

add_filter( 'woocommerce_appointments_time_slot_html', function( $slot_html, $display_slot, $quantity, $time_to_check, $staff_id, $timezone, $product, $spaces_left, $args ) {
    // Add custom class to low availability slots
    if ( $spaces_left <= 2 ) {
        $slot_html = str_replace( 'class="', 'class="low-availability ', $slot_html );
    }
    return $slot_html;
}, 10, 9 );

`appointment_form_posted_total_duration`

Filters total duration from form data.

Parameters:

$duration (int) - Duration in minutes
$product (WC_Product_Appointment) - The product object
$posted (array) - Posted form data

Returns: (int) Modified duration

Since: 3.0.0

Appointment Behavior

`woocommerce_appointment_requires_confirmation`

Filters whether an appointment requires confirmation.

Parameters:

$requires_confirmation (bool) - Whether confirmation is required
$product (WC_Product_Appointment) - The product object

Returns: (bool) Modified requirement

Since: 3.0.0

Example:

add_filter( 'woocommerce_appointment_requires_confirmation', function( $requires_confirmation, $product ) {
    // Always require confirmation for specific product
    if ( $product->get_id() === 123 ) {
        return true;
    }
    return $requires_confirmation;
}, 10, 2 );

`woocommerce_appointment_user_can_cancel`

Filters whether a user can cancel an appointment.

Parameters:

$can_cancel (bool) - Whether user can cancel
$appointment (WC_Appointment) - The appointment object

Returns: (bool) Modified permission

Since: 3.0.0

Example:

add_filter( 'woocommerce_appointment_user_can_cancel', function( $can_cancel, $appointment ) {
    // Prevent cancellation within 24 hours
    $hours_until_start = ( $appointment->get_start() - time() ) / HOUR_IN_SECONDS;
    if ( $hours_until_start < 24 ) {
        return false;
    }
    return $can_cancel;
}, 10, 2 );

`woocommerce_appointment_user_can_reschedule`

Filters whether a user can reschedule an appointment.

Parameters:

$can_reschedule (bool) - Whether user can reschedule
$appointment (WC_Appointment) - The appointment object

Returns: (bool) Modified permission

Since: 3.0.0

Example:

add_filter( 'woocommerce_appointment_user_can_reschedule', function( $can_reschedule, $appointment ) {
    // Only allow rescheduling for confirmed appointments
    if ( $appointment->get_status() !== 'confirmed' ) {
        return false;
    }
    return $can_reschedule;
}, 10, 2 );

`woocommerce_appointment_cancelled_notice`

Filters the cancellation notice message.

Parameters:

$message (string) - The notice message

Returns: (string) Modified message

Since: 3.0.0

Example:

add_filter( 'woocommerce_appointment_cancelled_notice', function( $message ) {
    return 'Your appointment has been successfully cancelled. We hope to see you again soon!';
}, 10, 1 );

`woocommerce_appointment_rescheduled_notice`

Filters the reschedule notice message.

Parameters:

$message (string) - The notice message
$appointment (WC_Appointment) - The appointment object
$prev_start_date (int) - Previous start date timestamp
$prev_end_date (int) - Previous end date timestamp

Returns: (string) Modified message

Since: 3.0.0

`woocommerce_appointments_cancel_appointment_redirect`

Filters redirect URL after appointment cancellation.

Parameters:

$redirect (string) - Redirect URL
$appointment_id (int) - The appointment ID

Returns: (string) Modified URL

Since: 3.0.0

Example:

add_filter( 'woocommerce_appointments_cancel_appointment_redirect', function( $redirect, $appointment_id ) {
    return wc_get_page_permalink( 'myaccount' ) . 'appointments/';
}, 10, 2 );

`woocommerce_appointments_reschedule_appointment_redirect`

Filters redirect URL after appointment rescheduling.

Parameters:

$redirect (string) - Redirect URL
$appointment_id (int) - The appointment ID

Returns: (string) Modified URL

Since: 3.0.0

Product Settings

`woocommerce_appointments_get_duration`

Filters appointment duration.

Parameters:

$value (int) - Duration value
$product (WC_Product_Appointment) - The product object

Returns: (int) Modified duration

Since: 3.0.0

`woocommerce_appointments_get_duration_unit`

Filters duration unit.

Parameters:

$unit (string) - Duration unit (minute, hour, day, month)
$product (WC_Product_Appointment) - The product object

Returns: (string) Modified unit

Since: 3.0.0

`woocommerce_appointments_get_duration_in_minutes`

Filters duration in minutes.

Parameters:

$duration (int) - Duration in minutes
$product (WC_Product_Appointment) - The product object

Returns: (int) Modified duration

Since: 3.0.0

`woocommerce_appointments_quantity_input_max`

Filters maximum quantity input for a product.

Parameters:

$max (int) - Maximum quantity
$product (WC_Product_Appointment) - The product object

Returns: (int) Modified maximum

Since: 3.0.0

Example:

add_filter( 'woocommerce_appointments_quantity_input_max', function( $max, $product ) {
    // Limit to 5 per customer
    return min( $max, 5 );
}, 10, 2 );

Google Calendar Sync

`woocommerce_appointments_gcal_sync_statuses`

Filters appointment statuses that trigger Google Calendar sync.

Parameters:

$statuses (array) - Array of statuses to sync

Returns: (array) Modified statuses array

Since: 3.0.0

Default: ['paid', 'confirmed', 'complete']

Example:

add_filter( 'woocommerce_appointments_gcal_sync_statuses', function( $statuses ) {
    // Also sync pending-confirmation status
    $statuses[] = 'pending-confirmation';
    return $statuses;
}, 10, 1 );

`woocommerce_appointments_gcal_statuses`

Filters appointment statuses that sync to Google Calendar.

Parameters:

$statuses (array) - Array of statuses

Returns: (array) Modified statuses array

Since: 3.0.0

`wc_appointments_sync_with_padding`

Controls whether padding time syncs to Google Calendar.

Parameters:

$sync (bool) - Whether to sync padding

Returns: (bool) Modified sync setting

Since: 3.0.0

Display & Formatting

`woocommerce_appointments_date_format`

Filters date format for appointments.

Parameters:

$format (string) - Date format string

Returns: (string) Modified format

Since: 3.0.0

Example:

add_filter( 'woocommerce_appointments_date_format', function( $format ) {
    return 'l, F j, Y'; // Monday, January 1, 2024
}, 10, 1 );

`woocommerce_appointments_time_format`

Filters time format for appointments.

Parameters:

$format (string) - Time format string

Returns: (string) Modified format

Since: 3.0.0

`woocommerce_appointment_get_permalink`

Filters appointment permalink.

Parameters:

$permalink (string) - The permalink
$appointment (WC_Appointment) - The appointment object

Returns: (string) Modified permalink

Since: 3.0.0

`woocommerce_appointments_get_status_label`

Filters status label for display.

Parameters:

$label (string) - Status label
$status (string) - Status slug

Returns: (string) Modified label

Since: 3.0.0

Example:

add_filter( 'woocommerce_appointments_get_status_label', function( $label, $status ) {
    if ( 'pending-confirmation' === $status ) {
        return 'Awaiting Confirmation';
    }
    return $label;
}, 10, 2 );

`wc_appointment_pretty_timestamp`

Filters pretty formatted timestamp.

Parameters:

$return (string) - Formatted timestamp string
$time (int) - Unix timestamp

Returns: (string) Modified formatted string

Since: 3.0.0

`wc_appointment_pretty_addon_duration`

Filters pretty formatted addon duration HTML.

Parameters:

$html (string) - HTML string
$time (int) - Time in minutes
$product (WC_Product_Appointment) - The product object

Returns: (string) Modified HTML

Since: 3.0.0

Cart & Checkout

`woocommerce_appointments_remove_inactive_cart_time`

Filters cart hold time in minutes before removing inactive appointments.

Parameters:

$minutes (int) - Hold time in minutes

Returns: (int) Modified minutes

Since: 3.0.0

Default: 60 minutes

Example:

add_filter( 'woocommerce_appointments_remove_inactive_cart_time', function( $minutes ) {
    // Extend to 2 hours
    return 120;
}, 10, 1 );

My Account

`woocommerce_appointments_account_endpoint`

Filters My Account appointments endpoint slug.

Parameters:

$endpoint (string) - Endpoint slug

Returns: (string) Modified endpoint

Since: 3.0.0

Default: 'appointments'

Example:

add_filter( 'woocommerce_appointments_account_endpoint', function( $endpoint ) {
    return 'bookings'; // Change to /my-account/bookings/
}, 10, 1 );

`woocommerce_appointments_my_appointments_per_page`

Filters appointments per page in My Account.

Parameters:

$per_page (int) - Items per page

Returns: (int) Modified per page count

Since: 3.0.0

Admin Interface

`woocommerce_appointments_admin_list_table_filters`

Adds custom filters to the admin appointments list table.

Parameters:

$filters (array) - Array of filter options

Returns: (array) Modified filters

Since: 3.0.0

`woocommerce_appointments_admin_buyer_name`

Customizes buyer name display in admin.

Parameters:

$name (string) - Buyer name
$appointment (WC_Appointment) - The appointment object

Returns: (string) Modified name

Since: 3.0.0

`woocommerce_appointments_appointment_cost_html`

Filters appointment cost HTML in admin.

Parameters:

$html (string) - Cost HTML
$product (WC_Product_Appointment|null) - The product object
$posted (array) - Posted data

Returns: (string) Modified HTML

Since: 3.0.0

Performance & Caching

`wc_appointments_cache_horizon_months`

Filters cache horizon in months for availability calculations.

Parameters:

$months (int) - Number of months to cache

Returns: (int) Modified months

Since: 3.0.0

Example:

add_filter( 'wc_appointments_cache_horizon_months', function( $months ) {
    // Cache 6 months ahead instead of default
    return 6;
}, 10, 1 );

`woocommerce_appointments_booking_lock_ttl`

Filters booking lock TTL in seconds.

Parameters:

$ttl (int) - Time to live in seconds

Returns: (int) Modified TTL

Since: 3.0.0

Default: 5 seconds

Order Integration

`woocommerce_appointments_zero_order_status`

Filters order status for zero-total orders.

Parameters:

$status (string) - Order status
$order (WC_Order) - The order object

Returns: (string) Modified status

Since: 3.0.0

Default: 'completed'

Example:

add_filter( 'woocommerce_appointments_zero_order_status', function( $status, $order ) {
    // Use 'processing' for zero-total orders
    return 'processing';
}, 10, 2 );

`woocommerce_appointments_stop_order_delete`

Filters whether to prevent order deletion when it has appointments.

Parameters:

$delete (bool) - Whether to allow deletion
$order_id (int) - The order ID
$appointment_id (int) - The appointment ID

Returns: (bool) Modified permission

Since: 3.0.0

`woocommerce_appointments_stop_order_update`

Filters whether to prevent order status update.

Parameters:

$stop (bool) - Whether to stop update
$order (WC_Order) - The order object
$appointment_id (int) - The appointment ID
$status (string) - New status

Returns: (bool) Modified permission

Since: 3.0.0

REST API

`woocommerce_rest_availabilities_query`

Modifies availability API query arguments.

Parameters:

$args (array) - Query arguments

Returns: (array) Modified arguments

Since: 3.0.0

`woocommerce_appointments_product_type_rest_check`

Validates product type for REST API requests.

Parameters:

$is_valid (bool) - Whether product type is valid
$product (WC_Product) - The product object

Returns: (bool) Modified validation

Since: 3.0.0

Email Notifications

`woocommerce_email_recipient_admin_new_appointment`

Filters email recipients for admin new appointment email.

Parameters:

$recipients (string|array) - Email recipients
$appointment (WC_Appointment) - The appointment object

Returns: (string|array) Modified recipients

Since: 3.0.0

Example:

add_filter( 'woocommerce_email_recipient_admin_new_appointment', function( $recipients, $appointment ) {
    // Add additional recipient
    if ( is_string( $recipients ) ) {
        $recipients = array( $recipients, 'manager@example.com' );
    } else {
        $recipients[] = 'manager@example.com';
    }
    return $recipients;
}, 10, 2 );

`woocommerce_email_recipient_admin_appointment_cancelled`

Filters email recipients for admin appointment cancelled email.

Parameters:

$recipients (string|array) - Email recipients
$appointment (WC_Appointment) - The appointment object

Returns: (string|array) Modified recipients

Since: 3.0.0

`woocommerce_email_recipient_admin_appointment_rescheduled`

Filters email recipients for admin appointment rescheduled email.

Parameters:

$recipients (string|array) - Email recipients
$appointment (WC_Appointment) - The appointment object

Returns: (string|array) Modified recipients

Since: 3.0.0

`woocommerce_appointments_emails_ics`

Controls whether ICS calendar files are attached to emails.

Parameters:

$attach (bool) - Whether to attach ICS

Returns: (bool) Modified setting

Since: 3.0.0

Default: true

Best Practices

Priority

When using hooks, consider the priority parameter:

// Default priority is 10
add_action( 'woocommerce_new_appointment', 'my_function' );

// Higher priority runs earlier
add_action( 'woocommerce_new_appointment', 'my_early_function', 5 );

// Lower priority runs later
add_action( 'woocommerce_new_appointment', 'my_late_function', 20 );

Parameter Count

Always specify the correct number of parameters when using filters or actions with multiple parameters:

// Correct - specifies 4 parameters
add_action( 'woocommerce_appointment_status_changed', function( $from, $to, $appointment_id, $appointment ) {
    // Your code
}, 10, 4 );

Returning Values

Filters must always return a value:

add_filter( 'woocommerce_appointment_user_can_cancel', function( $can_cancel, $appointment ) {
    // Always return the modified value
    return $can_cancel && some_condition();
}, 10, 2 );

Performance

Be mindful of performance when hooking into frequently called filters:

// Cache expensive operations
add_filter( 'woocommerce_appointments_get_available_quantity', function( $qty, $product, $staff_id ) {
    static $cache = array();
    $cache_key = $product->get_id() . '_' . $staff_id;
    
    if ( isset( $cache[ $cache_key ] ) ) {
        return $cache[ $cache_key ];
    }
    
    $result = expensive_calculation( $qty, $product, $staff_id );
    $cache[ $cache_key ] = $result;
    
    return $result;
}, 10, 3 );

Common Use Cases

Custom Validation

add_filter( 'woocommerce_appointments_get_posted_data', function( $data, $product, $posted ) {
    // Validate custom field
    if ( empty( $posted['special_requirements'] ) && $product->get_id() === 123 ) {
        wc_add_notice( 'Special requirements are required for this appointment.', 'error' );
        return false;
    }
    return $data;
}, 10, 3 );

Dynamic Pricing

add_filter( 'woocommerce_appointments_get_posted_data', function( $data, $product, $posted ) {
    // Add custom pricing based on date
    $start_date = $data['_start'];
    $day_of_week = date( 'w', $start_date );
    
    if ( $day_of_week == 0 || $day_of_week == 6 ) {
        $data['_cost'] = $data['_cost'] * 1.5; // Weekend surcharge
    }
    
    return $data;
}, 10, 3 );

Custom Notifications

add_action( 'woocommerce_appointment_confirmed', function( $appointment_id, $appointment ) {
    // Send SMS notification
    $phone = $appointment->get_customer()->get_billing_phone();
    if ( $phone ) {
        send_sms( $phone, "Your appointment #{$appointment_id} has been confirmed!" );
    }
}, 10, 2 );

External Service Required

This example requires an SMS service provider (e.g., Twilio, Nexmo, AWS SNS) or an SMS plugin. The send_sms() function is not part of WordPress core or WooCommerce Appointments. You'll need to:

Install an SMS plugin (e.g., WooCommerce Twilio SMS), or
Implement your own SMS integration using a service provider's API

The admin calendar's appointment view modal supports JavaScript hooks for customizing its content. These hooks allow you to filter existing sections or add custom content at specific positions—all without modifying core plugin files.

Dynamic Content

The appointment modal content is dynamically generated using React. All data (customer info, order details, pricing, etc.) is fetched via REST API when the modal opens. Your hook callbacks receive the full appointment data object plus a context with helper functions.

The Hooks API

Access the hooks system via window.wcaModalHooks:

Method	Description
`addFilter( hook, callback, priority )`	Register a filter (priority default: 10, lower runs first)
`removeFilter( hook, callback )`	Remove a previously registered callback
`applyFilters( hook, value, appt, context )`	Apply all filters to a value
`hasFilters( hook )`	Check if any filters are registered

Available Hooks

Section Filters

Use these to modify existing content. Your callback receives the current content, modifies it, and returns the result.

Hook	What It Filters	Callback Receives
`appointment_modal_header`	Header row (title)	React element
`appointment_modal_customer_section`	Customer info rows	Array of `{ label, value, key }`
`appointment_modal_schedule_section`	When/Duration rows	Array of `{ label, value, key }`
`appointment_modal_staff_section`	Staff info rows	Array of `{ label, value, key }`
`appointment_modal_addons_section`	Add-ons rows	Array of `{ label, value, key }`
`appointment_modal_pricing_section`	Pricing/order section	React element
`appointment_modal_footer_actions`	Status action controls in the modal status section	Array of React elements

Insertion Points

Use these to add custom content at specific positions. Return an array of React elements.

Hook	Position
`appointment_modal_after_header`	After header, before body content
`appointment_modal_after_customer`	After customer section
`appointment_modal_after_schedule`	After schedule (when/duration) section
`appointment_modal_after_staff`	After staff section
`appointment_modal_after_addons`	After add-ons section
`appointment_modal_after_pricing`	After pricing section
`appointment_modal_before_footer`	Before footer buttons

Context Object

Every callback receives a context object with useful data and helpers:

{
    h,              // React createElement function - use this to create elements
    t,              // Translation function: t( 'key', 'Fallback text' )
    i18n,           // Full i18n translations object
    appt,           // The appointment data object
    orderInfo,      // WooCommerce order data (if available)
    staffList,      // Array of all staff members
    products,       // Array of all appointable products
    adminBase,      // WordPress admin URL (e.g., '/wp-admin/')
    adminPost,      // Admin post.php URL
    customerAvatar, // Customer avatar URL
    staffAvatar,    // Staff member avatar URL
    displayName,    // Customer display name
    resolvedStaffName, // Staff member name
    rangeText,      // Formatted date/time range string
    durationText    // Formatted duration string
}

Examples

Add a Custom Row to the Customer Section

Add extra information below the existing customer row:

window.wcaModalHooks.addFilter(
    'appointment_modal_customer_section',
    function( rows, appt, ctx ) {
        // rows is an array of { label, value, key } objects
        
        // Add a VIP badge if customer has made 10+ appointments
        if ( appt.customer_appointment_count >= 10 ) {
            rows.push({
                label: 'Status',
                value: ctx.h( 'span', { 
                    className: 'wca-vip-badge',
                    style: { color: 'gold', fontWeight: 'bold' }
                }, '⭐ VIP Customer' ),
                key: 'vip-status'
            });
        }
        
        return rows; // Always return the rows array
    },
    10 // Priority (optional, default is 10)
);

Add Custom Content After a Section

Insert entirely new content after the customer section:

window.wcaModalHooks.addFilter(
    'appointment_modal_after_customer',
    function( content, appt, ctx ) {
        var h = ctx.h; // Get the createElement function
        
        // Add a custom notes display
        if ( appt.meta && appt.meta._customer_notes ) {
            content.push(
                h( 'div', { 
                    key: 'customer-notes',
                    className: 'wca-custom-notes',
                    style: { 
                        padding: '10px', 
                        background: '#f0f0f1', 
                        margin: '10px 0',
                        borderRadius: '4px'
                    }
                },
                    h( 'strong', null, 'Customer Notes: ' ),
                    appt.meta._customer_notes
                )
            );
        }
        
        return content; // Always return the content array
    }
);

Add a Custom Status Action

Add your own action control alongside the built-in status controls:

window.wcaModalHooks.addFilter(
    'appointment_modal_footer_actions',
    function( buttons, appt, ctx ) {
        var h = ctx.h;
        
        // Add a "Send Reminder" button
        buttons.push(
            h( 'a', {
                key: 'send-reminder',
                className: 'button wc-action-button',
                href: '#',
                title: 'Send a reminder email to the customer',
                onClick: function( e ) {
                    e.preventDefault();
                    
                    // Make an AJAX call to send reminder
                    fetch( '/wp-admin/admin-ajax.php', {
                        method: 'POST',
                        headers: { 'Content-Type': 'application/x-www-form-urlencoded' },
                        body: 'action=send_appointment_reminder&appointment_id=' + appt.id
                    })
                    .then( function() {
                        alert( 'Reminder sent!' );
                    });
                }
            }, 'Send Reminder' )
        );
        
        return buttons;
    }
);

Modify the Schedule Section

Add or modify the when/duration information:

window.wcaModalHooks.addFilter(
    'appointment_modal_schedule_section',
    function( rows, appt, ctx ) {
        // Add timezone information
        var timezone = Intl.DateTimeFormat().resolvedOptions().timeZone;
        rows.push({
            label: 'Timezone',
            value: timezone,
            key: 'timezone'
        });
        
        // Add days until appointment
        if ( appt.start ) {
            var start = new Date( appt.start * 1000 );
            var now = new Date();
            var days = Math.ceil( ( start - now ) / ( 1000 * 60 * 60 * 24 ) );
            
            if ( days > 0 ) {
                rows.push({
                    label: 'Days Away',
                    value: days + ' day' + ( days !== 1 ? 's' : '' ),
                    key: 'days-away'
                });
            }
        }
        
        return rows;
    }
);

Where to Add Your Code

You can add these hooks via:

Code Snippets Plugin - Add to a custom snippet that runs on admin pages
Custom Plugin - Enqueue your JS file on the appointments admin page
Theme functions.php - Enqueue JavaScript for admin

Example of enqueueing your custom JS:

add_action( 'admin_enqueue_scripts', function( $hook ) {
    // Only load on the appointments calendar page
    if ( 'wc_appointment_page_appointment_calendar' !== $hook ) {
        return;
    }
    
    wp_enqueue_script(
        'my-appointment-modal-hooks',
        plugin_dir_url( __FILE__ ) . 'js/my-modal-hooks.js',
        array(), // Dependencies
        '1.0.0',
        true // Load in footer
    );
});

Performance Notes

Zero overhead when no hooks are registered (fast-path check)
Hooks only execute when the modal opens, not on calendar load
The context object is created once per modal render and reused
No impact on initial page load or calendar performance

Actions​

Appointment Lifecycle​

woocommerce_new_appointment​

woocommerce_appointment_status_changed​

woocommerce_appointment_{status}​

woocommerce_appointment_{old_status}_to_{new_status}​

woocommerce_appointment_cancelled​

woocommerce_appointment_staff_changed​

woocommerce_appointments_rescheduled_appointment​

woocommerce_appointments_cancelled_appointment​

woocommerce_new_appointment_order​

Admin Interface​

woocommerce_appointments_after_staff_cost​

woocommerce_appointments_after_staff_qty​

Google Calendar Integration​

woocommerce_appointments_sync_from_gcal_event_start​

Indexing & Performance​

wc_appointments_index_availability_rule​

wc_appointments_index_appointment​

Filters​

Availability & Scheduling​

woocommerce_appointments_get_posted_data​

woocommerce_appointments_get_available_quantity​

woocommerce_appointments_time_slots​

woocommerce_appointments_time_slot_html​

appointment_form_posted_total_duration​

Appointment Behavior​

woocommerce_appointment_requires_confirmation​

woocommerce_appointment_user_can_cancel​

woocommerce_appointment_user_can_reschedule​

woocommerce_appointment_cancelled_notice​

woocommerce_appointment_rescheduled_notice​

woocommerce_appointments_cancel_appointment_redirect​

woocommerce_appointments_reschedule_appointment_redirect​

Product Settings​

woocommerce_appointments_get_duration​

woocommerce_appointments_get_duration_unit​

woocommerce_appointments_get_duration_in_minutes​

woocommerce_appointments_quantity_input_max​

Google Calendar Sync​

woocommerce_appointments_gcal_sync_statuses​

woocommerce_appointments_gcal_statuses​

wc_appointments_sync_with_padding​

Display & Formatting​

woocommerce_appointments_date_format​

woocommerce_appointments_time_format​

woocommerce_appointment_get_permalink​

woocommerce_appointments_get_status_label​

wc_appointment_pretty_timestamp​

wc_appointment_pretty_addon_duration​

Cart & Checkout​

woocommerce_appointments_remove_inactive_cart_time​

My Account​

woocommerce_appointments_account_endpoint​

woocommerce_appointments_my_appointments_per_page​

Admin Interface​

woocommerce_appointments_admin_list_table_filters​

woocommerce_appointments_admin_buyer_name​

woocommerce_appointments_appointment_cost_html​

Performance & Caching​

wc_appointments_cache_horizon_months​

woocommerce_appointments_booking_lock_ttl​

Order Integration​

woocommerce_appointments_zero_order_status​

woocommerce_appointments_stop_order_delete​

woocommerce_appointments_stop_order_update​

REST API​

woocommerce_rest_availabilities_query​

woocommerce_appointments_product_type_rest_check​

Email Notifications​

woocommerce_email_recipient_admin_new_appointment​

woocommerce_email_recipient_admin_appointment_cancelled​

woocommerce_email_recipient_admin_appointment_rescheduled​

woocommerce_appointments_emails_ics​

Best Practices​

Priority​

Parameter Count​

Returning Values​

Performance​

Common Use Cases​

Actions

Appointment Lifecycle

`woocommerce_new_appointment`

`woocommerce_appointment_status_changed`

`woocommerce_appointment_{status}`

`woocommerce_appointment_{old_status}_to_{new_status}`

`woocommerce_appointment_cancelled`

`woocommerce_appointment_staff_changed`

`woocommerce_appointments_rescheduled_appointment`

`woocommerce_appointments_cancelled_appointment`

`woocommerce_new_appointment_order`

Admin Interface

`woocommerce_appointments_after_staff_cost`

`woocommerce_appointments_after_staff_qty`

Google Calendar Integration

`woocommerce_appointments_sync_from_gcal_event_start`

Indexing & Performance

`wc_appointments_index_availability_rule`

`wc_appointments_index_appointment`

Filters

Availability & Scheduling

`woocommerce_appointments_get_posted_data`

`woocommerce_appointments_get_available_quantity`

`woocommerce_appointments_time_slots`

`woocommerce_appointments_time_slot_html`

`appointment_form_posted_total_duration`

Appointment Behavior

`woocommerce_appointment_requires_confirmation`

`woocommerce_appointment_user_can_cancel`

`woocommerce_appointment_user_can_reschedule`

`woocommerce_appointment_cancelled_notice`

`woocommerce_appointment_rescheduled_notice`

`woocommerce_appointments_cancel_appointment_redirect`

`woocommerce_appointments_reschedule_appointment_redirect`

Product Settings

`woocommerce_appointments_get_duration`

`woocommerce_appointments_get_duration_unit`

`woocommerce_appointments_get_duration_in_minutes`

`woocommerce_appointments_quantity_input_max`

Google Calendar Sync

`woocommerce_appointments_gcal_sync_statuses`

`woocommerce_appointments_gcal_statuses`

`wc_appointments_sync_with_padding`

Display & Formatting

`woocommerce_appointments_date_format`

`woocommerce_appointments_time_format`

`woocommerce_appointment_get_permalink`

`woocommerce_appointments_get_status_label`

`wc_appointment_pretty_timestamp`

`wc_appointment_pretty_addon_duration`

Cart & Checkout

`woocommerce_appointments_remove_inactive_cart_time`

My Account

`woocommerce_appointments_account_endpoint`

`woocommerce_appointments_my_appointments_per_page`

Admin Interface

`woocommerce_appointments_admin_list_table_filters`

`woocommerce_appointments_admin_buyer_name`

`woocommerce_appointments_appointment_cost_html`

Performance & Caching

`wc_appointments_cache_horizon_months`

`woocommerce_appointments_booking_lock_ttl`

Order Integration

`woocommerce_appointments_zero_order_status`

`woocommerce_appointments_stop_order_delete`

`woocommerce_appointments_stop_order_update`

REST API

`woocommerce_rest_availabilities_query`

`woocommerce_appointments_product_type_rest_check`

Email Notifications

`woocommerce_email_recipient_admin_new_appointment`

`woocommerce_email_recipient_admin_appointment_cancelled`

`woocommerce_email_recipient_admin_appointment_rescheduled`

`woocommerce_appointments_emails_ics`

Best Practices

Priority

Parameter Count

Returning Values

Performance

Common Use Cases