Create a coupon

// For coupons with "amount off" discount
{
    "coupon": "coupon-id", // required, alphanumeric coupon ID
    "discount" {"type": "flat", "amount": {"USD": 8, "EUR": 10}}, // required - valid values for type are flat and percent. Flat expects object with amount off per currency.
    "combine": true, // corresponding to "combine discounts" in the interface. optional, default: false. If enabled will apply coupon discount in addition to the product discount.
    "reason": {"en": "Your Reason", "de": "Your Reason in German"}, //optional - discount reason visible to end users, object with all languages you want to enter it in.
    "limit": 10,  // optional - use limit for each coupon code
    "available": {"start":"2015-08-15", "end": "2015-09-15"},  // optional, also accepts timestamp in milliseconds and datetime string  e.g. "2015-09-01 08:00" to set "start time" or "end time"
     "codes": ["code1", "code2", ...] //optional, actual coupon codes which trigger this discount
    "products": ["product-id", "another-product-id"] // optional - array of product ids to which this discount applies. If not provided applies to all products.
}

// For coupons with "percentage off" discount
// Use the same syntax as above but different type for "discount":
"discount": {"type": "percent", "percent": 20},