SwftBumps

Order bumps for Swft Checkout. Offer additional products at a discounted price on the payment step. Accepted bumps are added to the Stripe PaymentIntent amount and included in the WooCommerce order.

What it does

• Define bump offers: a product, a headline, a description, and an optional discount
• Bumps appear on the payment step of the Swft Checkout, below the review strip
• Customer accepts or declines with a single click
• Accepted bumps update the Stripe PaymentIntent amount via POST /sessions/:id/apply-bumps
• Accepted bumps are added to the WooCommerce order as line items

Installation

1. Download swft-bumps.zip from swft.co.uk/modules
2. Install and activate
3. Go to WooCommerce → Bumps → Add New to create bump offers

Bump configuration

Each bump is a custom post type (swft_bump):

Field	Meta key	Description
Product	_bump_product_id	WooCommerce product ID to add to order
Headline	_bump_headline	Short headline shown prominently
Description	_bump_description	Supporting text (optional)
Discount label	_bump_discount_label	e.g. “Save 30% today only”
Trigger	_bump_trigger_product_ids	Show bump only when these product IDs are in cart
Trigger category	_bump_trigger_category_ids	Show bump when cart contains product in these categories

Extension data

SwftBumps adds the following to extensions.order_bumps in the session:

[
  {
    "product_id": 789,
    "name": "Premium Packaging",
    "headline": "Add premium packaging for just £3",
    "description": "Black gift box with ribbon. Limited to one per order.",
    "price": 300,
    "original_price": 500,
    "discount_label": "40% off today",
    "image": "https://yourstore.com/wp-content/uploads/box.jpg",
    "sku": "PREM-BOX-01"
  }
]

The checkout frontend reads this and renders the bump UI on the payment step.

How payment works

When the customer accepts a bump:

1. The checkout calls POST api.swft.co.uk/sessions/{id}/apply-bumps with accepted_bump_ids: [789]
2. The API calculates the additional amount and calls stripe.paymentIntents.update() with the new total
3. The accepted bumps are stored in session_data.extensions.accepted_bumps
4. The WooCommerce order sync adds accepted bump products as line items

Order meta

Meta key	Value
_swft_ext_order_bumps	Full bumps array as JSON
_swft_ext_accepted_bumps	Accepted bumps as JSON

JS events

document.addEventListener('swftcheckout:ready', () => {
  // Bumps are shown automatically if extensions.order_bumps is non-empty.
  // Listen for this event if you need to react when bumps render.
})

document.addEventListener('swftcheckout:upsell-shown', (e) => {
  // Fires when the bump UI renders
  console.log(e.detail.products)
})

PHP hooks

// Modify which bumps are shown for a given cart
add_filter( 'swft_bumps_for_cart', function( array $bumps, WC_Cart $cart ): array {
    // Remove a bump if a condition is met
    return array_filter( $bumps, fn( $b ) => $b['product_id'] !== 999 );
}, 10, 2 );

// Add custom data to each bump object in the extensions array
add_filter( 'swft_bump_extension_data', function( array $bump, int $product_id ): array {
    $bump['stock_remaining'] = get_post_meta( $product_id, '_stock', true );
    return $bump;
}, 10, 2 );

// Fired after bumps are applied to the order
add_action( 'swft_bumps_applied', function( WC_Order $order, array $accepted_bumps ): void {
    // notify fulfilment system
}, 10, 2 );