InventoryAPI by Erply is a powerful backend for web shops, and more.
This is a list of all API functions. Click on function name and you'll find all required and optional input parameters and response fields.
getApplianceslists your appliance/vehicle database.
applyPromotions. (As input; you need to send all the items on your receipt; API will return the same list, with final prices for each item added.)
getTimeSlotsand select a different start and end time for new appointment.)