Create a checkout
Opens a checkout for the token’s company and prices the cart when it is priceable. A cart the purchase rules reject is still created, open, with the one problem that says why; a refusal creates nothing. The response carries the version every later write must send, and expires_at says when an open checkout closes on its own.
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.
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. Defaults to change.