Update a checkout
Replaces the cart and prices it again. Send the version last read; a stale one answers 409 and changes nothing, so read the checkout and send the write again at its version. A cart the purchase rules reject is saved with its price cleared and one problem saying why, and the version still advances. The X-Checkout-Session-ID response header names the session this price belongs to; send it back on the finalize that follows.
Authentication
A temporary access token in the X-Schematic-Api-Key header. Your server mints it with POST /temporary-access-tokens on the secret-key API for a company, optionally for one of its users, and hands it to the page. The token fixes the company every request reads and writes.
Path parameters
checkout_id
Request
ISO 4217 currency this cart is being built in. Prices are still selected by id; this records the intent, and a cart that prices in another currency is reported as a problem.
What the checkout does to the subscription: change it to the cart’s contents, or cancel it. Omit it to keep the checkout’s current intent.