checkout:start

checkout:start starts checkout from a cart, performing the same validation the cart Pay button uses. It can be configured on a POS action item or called from custom JavaScript via pos-sc-action.

Parameters

Parameter	Type	Required	Description
cart_sc_id	String	No	Salesforce ID of the cart to start checkout from. If omitted, the active cart is used. If provided and different from the active cart, that cart is resumed first.

Behavior

1. If cart_sc_id refers to a cart other than the active one, the action resumes that cart first (using the same linkage safety check as cart:resume).
2. The cart is validated using the same rules the Pay button uses. If any check fails, an alert modal explains the reason and the action stops.
3. The checkout type is set to POS_ORDER.
4. If the cart has a non-zero amount to pay (the common case), the user is taken to the checkout payment screen.
5. If the cart total is zero (e.g. a fully-deposited cart or a pure refund), the order is created immediately and the user is navigated to the order record. For refund carts, the matching credit p[…]

If cart_sc_id refers to a cart that is already linked to an order, the existing “order connected” modal is shown instead of starting checkout — matching the behavior of cart:resume.

Validation rules

The action shows an alert and stops if any of the following conditions are detected:

Reason	Alert message
empty_cart	Unable to start checkout with an empty cart
syncing	Cart is still syncing. Please wait and try again.
pending_items	Some items are still being added. Please wait and try again.
expired_items	A rental hold has expired. Review the cart before proceeding.
fulfillment_needs_attention	Delivery details have changed. Please confirm them before continuing.
customer_required_subscription	A customer is required to check out subscription items.
customer_required_serial_item	A customer is required to check out items with serial numbers.
customer_required_delivery	A customer is required to check out a delivery or non-takeaway fulfillment.
customer_required_rental	A customer is required to check out rental items.
customer_required_voucher	A customer is required for vouchers that auto-generate a code or PIN.
customer_required	A customer is required for this order.
serial_numbers_missing	Serial numbers are missing for one or more items.
invalid_discount	Cart discount exceeds the maximum allowed for the current items.

Returned context

When checkout starts successfully, the action returns context available to the next action in a chain or to Liquid templates:

Field	Type	When
cart_sc_id	String	Always (the active cart at completion)
order_id	String	Only when a zero-total order was created immediately

Usage

Action item configuration

Set the Action field on a s_c__Pos_Action_Item__c record:

checkout:start

To target a specific cart:

checkout:start

with Params set to:

cart_sc_id=<Salesforce cart ID>

Liquid/HTML template

html <button type="button" onclick="scAction('checkout:start')">Pay</button>

html <button type="button" onclick="scAction('checkout:start', { cart_sc_id: '{{ cart.id }}' })" > Resume and pay </button>

JavaScript

javascript scAction('checkout:start') scAction('checkout:start', { cart_sc_id: 'abc-123' })

With success/error handling:

javascript scAction( 'checkout:start', {}, { onSuccess: () => console.log('Checkout started'), onError: (error) => console.error('Could not start checkout:', error), } )