This section groups misc data for further customization of your checkout page. The following content is not necessary to start using paycertify.js and its audience is people who are looking into using the full capabilities of our plugin by creating more sensitive and complex rulesets.


Most of our fraud tools have rulesets for each one of the products you have activated under your account. These rulesets will define if a transaction should be forwarded to the gateway, or if it should be blocked. We give you the control on what you want to block, and consequently, what you want to let pass. All that is done through a logical formula that you will build, after getting to know how each product works. When your customer clicks to finish their checkout process and submits the form with their address, credit card data and personal information, we evaluate the response that we got for each one of the products being used, and use your rules to either allow the transaction to pass or not. Here’s an example:

Let’s say you are using Kount™. For every Kount request made, you get a response with a set of data, including a fraud score, the user’s network data, proxy data, geolocation data, and a verdict from Kount if they recommend you to allow that transaction to go through or not. Here’s an example response:


So given that set of data, we clearly see that:

  • The AUTO value is “D”;
  • BRND value is “NONE”;
  • SCOR is 98, and so on.

On that data structure, whatever is to the left side of the semi-colon are parameters and the right side of the semi-colons are values. The parameters do not change for each customer we’re evaluating – these parameters will always be returned by Kount™. What changes on a customer and sale basis are the values, which Kount (and any other product being used) has a dictionary to translate what they’re trying to tell us. Each pair of parameters and values define a condition that the fraud prevention tool is letting us know about.

For example, Kount’s automatic recommendation always comes back on the AUTO parameter. Whenever they send back a “D” on that field, that means “Decline”. So if you are following strictly Kount’s recommendations, you would want to create a rule that says the following:

Decline any transaction that Kount responds with the AUTO parameter having its value equals to "D"

Now, in order to inform the system of that you will need to create a logical expression, using one of the operators below:

Operator Name Meaning
= Equals to Parameter is exactly the same as the value
!= Not Equals to Parameter is not equal to the value
> Bigger than Parameter is greater than the value
>= Bigger than or equals to Parameter is greater than or equal to the value
< Smaller than Parameter is lesser than the value
<= Smaller than or equals to Parameter is lesser than or equal to the value

So in that case, the rule you’d like to insert to the system is:

AUTO = "D"

In that this above, you have

  • AUTO as the parameter;
  • = as the operator;
  • "D" as the value;

An example of use of other operators: the SCOR parameter represents a fraud score given by Kount™ to that transaction. The greater it is, greater is also the fraud propensity of that transaction. So in the case that you want to block any transactions that have a score greater than 50, you would create a rule like this:

Decline any transactions that have a SCOR greater than 50

Or, in a logical expression:

SCOR > 50

These operators are the main and most used ones, and the majority of our merchants do not need to use more than that – still, if you want to create more complex rules, check the appendix section for Advanced Operators.

Now, in order to create your first rule, we’ll get back where we left on Generate a Publishable Key Section. In that page you have the ability to enter rulesets for each one of the products. To set up a rule, click on the “Details” button for one of the keys. There you can use presets for rules, or just create a custom rule for each product. After choosing one of the options, apply the rule set and you should be good to go: that rule is immediately applied all of your checkout pages using this publishable key.

Keep in mind that when creating your rules, you should always write rules that will block a transaction from happening, so the condition to be matched needs to be what parameters and values pairs you want to block.

Next up we’ll list all the possible parameters and known values for each one of the products you can use with our Javascript Plugin. As a starting point, our system will suggest the simplest rulesets for you. If you’d like to dig in and understand which parameters are the best, keep reading below. Otherwise, you can just jump directly to the final section of this documentation on how to Setup the Plugin on your checkout page.