Merchant Tools

Shopping Cart Buttons

Shopping Cart Buttons
The buttons are implmented as standard HTML POST forms. The fields available are documented below.
Field NameDescriptionRequired?Length
Limit
Main Fields
cmdThis should always be set to '_cart_add'.YesN/A
resetThis tells the server to delete any cached cart data for the user.
Unless you can make sure reset is only set for the first item you add to the cart in general you don't want to set it.
No1
merchantYour merchant ID (you can find this on the My Account page).YesN/A
Cart Fields
cart_nameThe name of your shopping cart.Yes128
currencyThe currency of the items in the cart (BTC, LTC, USD, EUR, etc.).
Values supported: Any crypto or fiat currency on the Supported Coins page.
Note we in no way process any fiat currencies, they are simply convenience values so you don't have to convert to BTC or another coin yourself.
Yes3
invoiceThis is a passthru variable for your own use. [not visible to buyer]No128
customThis is a 2nd passthru variable for your own use. [not visible to buyer]No128
want_shipping1 = Want buyer's shipping information (default).
0 = Don't want buyer's shipping information.
No1
cart_shippingfA fixed shipping cost to charge (in addition to any shipping charged on a per-item basis).NoN/A
cart_taxfA tax cost to charge (in addition to any tax charged on a per-item basis).NoN/A
allow_quantity0 = Don't allow buyer to adjust quantity (default).
1 = Allow buyer to adjust quantity.
No1
allow_amount0 = Don't allow buyer to adjust item price (default).
1 = Allow buyer to adjust item price.
No1
allow_currency0 = Don't allow buyer to adjust source currency (default).
1 = Allow buyer to adjust source currency. (requires allow_amount = 1 and minamountf = 0 or not set)
No1
allow_currenciesCurrency codes separated with a comma of coins you will accept. This is used to further restrict the coin selection from your list of enabled coins; for example if you are doing your own exchange rates and want to limit checkout to a user selected currency.
Example: BTC,LTC
No255
allow_ship_countriesISO 3166 2 digit country codes separated with a comma of countries you will ship to. The will deny transactions if the shipping address is not in one of these countries.
Example: US,CA,GB
No255
Item/Payment Description Fields
amountfThe amount (in the currency chosen) of the item.YesN/A
item_nameThe name of the item to add to the cart.Yes128
item_numberThis is a passthru variable for your own use. [visible to buyer]No128
quantityLets you set a quantity of items. The purchase price will be quantity*amount from above.

Note: Must be 1 or higher, decimals are supported and will be rounded to 8 digits.
NoN/A
minamountfSets a minimum amountf (mainly for when allow_amount = 1). Does not work with allow_currency = 1NoN/A
on11st option name. This lets you pass through a buyer option like size or color.No
(unless ov1 set)
128
ov11st option value. This would be the buyer's selection such as small, large, red, white.No128
on22nd option name. This lets you pass through a buyer option like size or color.No
(unless ov2 set)
128
ov22nd option value. This would be the buyer's selection such as small, large, red, white.No128
shippingfCost of shipping the item.
Shipping cost is shippingf*quantity (unless shipping2 is set)
NoN/A
shipping2fCost of shipping each additional item.
Shipping cost is shippingf+((quantity-1)*shipping2f)
NoN/A
taxfAny tax to charge.NoN/A
Miscellaneous Fields
ipn_urlSets an IPN URL.
If not set or blank defaults to the IPN URL in your settings.
No255
return_urlSets a URL to go to after adding an item to the cart instead of going to the cart/checkout page.No255
success_urlSets a URL to go to if the buyer completes checkout.No255
cancel_urlSets a URL to go to continue shopping at your store.No255
allow_extraIf set to 1 will have a field where the buyer can leave you a note or extra information such as shipping address, size, or color.No1
langAutomatically set the checkout language to this language code. For a list of supported codes check this page.No16
cstyleSets a coin selection style for the checkout page. (default: grid1)No32
Buyer Information
These fields can be used to pre-populate forms with any information you already know about your buyer.
first_nameBuyer's first name.No32
last_nameBuyer's last name.No32
emailBuyer's email address.No128
address1Street / address line 1No128
address2Street / address line 2No128
cityCityNo64
stateState / ProvinceNo64
zipZip / Postal CodeNo32
countryCountry of Residence
This uses 2 digit ISO 3166 country codes.
No2
phonePhone NumberNo32
Feel free to check out our example buttons.