Cancels Mulberry plans on an order. Authenticate with your private API token.

Omit line_items to cancel every active plan on the order. Otherwise each line_items entry cancels one unit of its product; repeat an entry to cancel more units of the same product. Each unit takes the plan that best fits the request: first one covering more of the request's products, such as a bundle the request cancels in full, then one covering fewer products the request leaves out, then the oldest. That plan is cancelled, unless it's a bundle that also covers products the request leaves out: then the unit's product is removed from the bundle, which stays active at a new price. Entries for products with no Mulberry plan on the order are ignored, and so are entries without a product_id, except on an order from the Mulberry WooCommerce plugin: there an entry with an empty product_id cancels one plan on a product that no other entry names, which is how the plugin sends a product that has no SKU. Fulfilled plans (a claim was paid out) and plans already marked expired are never cancelled.

A request whose plans are all already cancelled answers 200 and changes nothing, so retrying a whole-order cancellation is safe. A partial request is not idempotent: sending the same line_items again cancels that many more units, while any remain active. Requests for the same order are processed one at a time, and one that waits more than five seconds for another to finish answers 503 without changing anything, so it can be retried.

A request answers 400 when it matches no plan on the order, when it matches only fulfilled or already-expired plans, or when its only change would be a bundle that can't be repriced. It answers 404 when your account has no order under order_id at all, in any status: the order may not have been created yet, so a client may retry the cancellation later. It answers 500 when an error stops it partway, and plans it cancelled before the error stay cancelled.