Checkout

Allowed countries

POST/checkout/allowedCountries

Lookup the allowed countries for this merchant id

City/State for Zip

POST/checkout/city_state

Look up the city and state for the shipping zip code.

Finalize Order

POST/checkout/cart/finalizeOrder

Finalize the cart into an order.

Get affirm checkout (by cart id)

GET/checkout/cart/{cart_id}/affirmCheckout

Get a Affirm checkout object for the specified cart_id parameter.

Get cart

GET/checkout/cart

If the cookie is set on the browser making the request then it will return their active cart.

Get cart (by cart id)

GET/checkout/cart/{cart_id}

Get a cart specified by the cart_id parameter.

Get cart (by return code)

GET/checkout/return/{return_code}

Get a cart specified by the return code parameter.

Get cart (by return token)

GET/checkout/return_token

Get a cart specified by the encrypted return token parameter.

Get state/province list for a country code

POST/checkout/stateProvincesForCountry/{country_code}

Lookup a state/province list for a given country code

Handoff cart

POST/checkout/cart/handoff

Handoff the browser to UltraCart for view cart on StoreFront, transfer to PayPal, transfer to Affirm, transfer to Sezzle or finalization of the order (including upsell processing).

Profile login

POST/checkout/cart/profile/login

Login in to the customer profile specified by cart.billing.email and password

Profile logout

POST/checkout/cart/profile/logout

Log the cart out of the current profile.

Profile registration

POST/checkout/cart/profile/register

Register a new customer profile.

Register affiliate click

POST/checkout/affiliateClick/register

Register an affiliate click.

Related items

POST/checkout/related_items

Retrieve all the related items for the cart contents.

Related items (specific item)

POST/checkout/relatedItems/{item_id}

Retrieve all the related items for the cart contents.

Setup Browser Application

PUT/checkout/browser_key

Setup a browser key authenticated application with checkout permissions.

Update cart

PUT/checkout/cart

Update the cart.

Validate

POST/checkout/cart/validate

Validate the cart for errors.

Webhooks

The following webhook events are available for this resource. See Webhooks for how delivery, retries, and versioning work.

Event	Description	Reflow	Expandable
checkout_cart_abandon	Fired when a cart is abandoned	—	Yes
checkout_cart_send_return_email	Fired when a return email should be sent to a customer	—	Yes

Receiving these events

• Payload: each delivery is a POST whose JSON body is an array of events, even when it carries one. Each element has a single key, the event name, whose value is the object, for example [{"checkout_cart_abandon": {...}}].
• Contents: the object includes only the parts in the webhook's expansion. Expansions appear when you edit the webhook after creating it.
• Respond within 30 seconds. Store or queue the payload and do the work in a background job.
• Batching: one delivery can bundle several events. The webhook sets how many (10 or more) and the maximum payload size (up to 900K).
• HTTPS: use it. It is required whenever the payload includes customer information.
• Testing: the webhook's test button sends a delivery, and its log shows each one. To resend existing records, for example to backfill a new receiver, request a reflow.

More: Webhooks, Creating a simple webhook (with a sample payload), receiver samples in PHP and Python