# Functions

Functions can be used as a condition in a Rule to silmplify writing rules and to make them more human readable. An agent bearer API-key is needed to create, change and list Functions.

Name	Arguments	True if...
`currencyOtherThan`	`Country`	authorization currency is something other than the specified currency
`cscMissing`		not a subsequent payment and the card csc is absent
`verificationThreshold`	`number`	authorization amount is greater than the argument, the authorization is not yet verified and it is not a subsequent recurring payment
`sanctionedCardCountry`		issuer country is a sanctioned country
`cardCountryNotEEA`		issuer country is not an EEA country
`sanctionedIpCountry`		the country of the card holder ip is a sanctioned country
`ipCountryNotEEA`		the country of the card holder is not an EEA country
`recurring`		the authorization is a recurring payment
`recurringNotVerified`		the authorization is a recurring payment and is not yet verified
`fraudio`		fraudio recommends blocking the transaction

# How to write Functions

The Functions object is of type Record<string, Detail> where the key is the name of the function and the value is an object which contains some detailed information about the function.

The Detail object includes:

The definition field works the same as a Rule condition. This is a boolean expression, created using information from:
The arguments field is a list of all arguments used in the function.
The Description field is optional and can include a summary of the function, a description of each argument used in the function and examples of how to use the function.

Example of a Functions object that sets a limit on the amount and currency for a transaction:

{
   "currencyOtherThan": {
        "definition": "!authorization.currency:value",
        "arguments": ["currency"],
        "description": {
            "arguments":{
                "currency": "The allowed currency of a transaction."
            },
            "example": {
                "currencyOtherThan(EUR)": "!authorization.currency:EUR",
                "currencyOtherThan(SEK)": "!authorization.currency:SEK"
            },
            "summary": "Currency limitation on a transaction."
       }
   }
}

Example rules:

"reject authorization if currencyOtherThan(EUR)"

"reject authorization if cscMissing()"

# Create

Example request:

POST /v1/merchant/functions

Content-Type: application/json
Authorization: Bearer <agent.api.key>

{
   "currencyOtherThan": {
        "definition": "!authorization.currency:value",
        "arguments": ["currency"],
        "description": {
            "arguments":{
                "currency": "The allowed currency of a transaction."
            },
            "example": {
                "currencyOtherThan(EUR)": "!authorization.currency:EUR",
                "currencyOtherThan(SEK)": "!authorization.currency:SEK"
            },
            "summary": "Currency limitation on the transactions."
       }
   }
}

# Change

Example request:

PUT /v1/merchant/functions

Content-Type: application/json
Authorization: Bearer <agent.api.key>

{
    "verificationThreshold": {
        "definition": "authorization.amount>threshold !authorization.verification:verified !authorization.recurring.type:subsequent",
        "arguments": ["threshold"],
        "description": {
            "arguments":{
                "threshold": "Maximum amount allowed for a transaction without requiring verification.",
            },
            "example": {
                "verificationThreshold(300)": "authorization.amount>300 !authorization.verification:verified !authorization.recurring.type:subsequent",
                "verificationThreshold(500)": "authorization.amount>500 !authorization.verification:verified !authorization.recurring.type:subsequent"
            },
            "summary": "Amount limitation for a transaction without requiring verification."
        }
    }
}

# List

Example request:

GET /v1/merchant/functions

Content-Type: application/json
Authorization: Bearer <agent.api.key>

Example response body:

{
   "currencyOtherThan": {
        "definition": "!authorization.currency:value",
        "arguments": ["currency"],
        "description": {
            "arguments":{
                "currency": "The allowed currency of a transaction."
            },
            "example": {
                "currencyOtherThan(EUR)": "!authorization.currency:EUR",
                "currencyOtherThan(SEK)": "!authorization.currency:SEK"
            },
            "summary": "Currency limitation on the transactions."
       }
   },
    "verificationThreshold": {
        "definition": "authorization.amount>threshold !authorization.verification:verified !authorization.recurring.type:subsequent",
        "arguments": ["threshold"],
        "description": {
            "arguments":{
                "threshold": "Maximum amount allowed for a transaction without requiring verification.",
            },
            "example": {
                "verificationThreshold(300)": "authorization.amount>300 !authorization.verification:verified !authorization.recurring.type:subsequent",
                "verificationThreshold(500)": "authorization.amount>500 !authorization.verification:verified !authorization.recurring.type:subsequent"
            },
            "summary": "Amount limitation for a transaction without requiring verification."
        }
    }
}