System functions reference

This document provides a reference for all system functions provided by Dialogflow.

You can apply inline system functions in your agent's conditions, static response messages (such as text responses, custom payloads, and conditional responses), parameter presets, and webhook header values to generate dynamic values during conversations.

Function syntax

All system functions follow the pattern of $sys.func.<FUNCTION NAME>(<ARGUMENT 1>, <ARGUMENT 2>, ...). For example, $sys.func.RAND(), $sys.func.ADD(1,2).

The names of the functions are all capitalized (except the random number generation function, which you can use with both RAND and the legacy name rand).

The arguments of the functions can be:

• inline values (such as number 1, string "abc", boolean true, and list [1, 2, 3])

• references to parameters (such as $session.params.a, check parameters guide for more details about the syntax of referencing parameters)

  Note: If the parameter referenced by the function expression is not set, it is treated as null.
  Note: Inline object (such as {"field" : "value"}) is not supported. Consider referencing the object through parameters.

• nested functions (such as $sys.func.ADD($sys.func.MINUS(2, 1), 3))

Check results of system functions

During the conversation, if Dialogflow evaluates any inline system function expressions to generate dynamic values, you can find the results of the evaluations in the QueryResult.

Specifically, there is a key called SystemFunctionResults in the DiagnosticInfo struct field, which logs the results (and errors) of system function evaluations.

Functions

Below are the system functions that Dialogflow currently supports.

ADD

You can use the ADD function to add multiple numbers together.

The function takes an arbitrary number of arguments. All arguments must be numbers.

For example, the following expression produces a value of 3.

$sys.func.ADD(1, 2)

ADD_DATE

You can use the ADD_DATE function to do arithmetic operations on dates.

The function takes the following arguments:

• the datetime object that you want to change
• the value you want to add (if positive) or subtract (if negative)
• the unit of time - string specifying the unit (days/months/hours/minutes) that you want to add/subract.

The list of supported units of time:

• "YEARS"
• "MONTHS"
• "DAYS"
• "WEEKS"
• "HOURS"
• "MINUTES"
• "SECONDS"

For example, the datetime struct representing 8/9/2021 15:23:10 may look like:

    {
        "year" : 2021
        "month" : 8,
        "day" : 9,
        "hours": 15,
        "minutes" : 23,
        "seconds" : 10,
        "nanos" : 0
    }

If it's stored in $session.params.time the ADD_DATE invocation will produce datetime objects like in the table below:

Expression	Result (datetime object)
$sys.func.ADD_DATE($session.params.time, 5, "DAYS")	8/14/2021 15:23:10
$sys.func.ADD_DATE($session.params.time, -9, "MONTHS")	11/9/2020 15:23:10
$sys.func.ADD_DATE($session.params.time, 38, "MINUTES")	8/9/2021 16:01:10

Note that the results are shown as a datetime string for convenience, but they are actually datetime objects, and you can use them with other functions like $sys.func.FORMAT_DATE or $sys.func.GET_FIELD:

Expression	Result
$sys.func.GET_FIELD($sys.func.ADD_DATE($session.params.time, 5, "DAYS"), "day")	14
$sys.func.FORMAT_DATE($sys.func.ADD_DATE($session.params.time, -9, "MONTHS"), "yy MMM dd")	20 Nov 09

APPEND

You can use the APPEND function to append value(s) to the end of a list.

The function takes the following arguments:

• the list to append values.

  Note: If the list is null, the function treats it as an empty list.

• an arbitrary number of values to be appended to the end of the list.

  If the value is a list, the values inside the list will be appended one by one.

For example:

Expression	Result
$sys.func.APPEND([1, 2, 3], 4)	[1, 2, 3, 4]
$sys.func.APPEND(["a", "b", "c"], "d", ["e", "f"])	["a", "b", "c", "d", "e", "f"]
$sys.func.APPEND(null, 1, 2, [3, 4])	[1, 2, 3, 4]

CONCATENATE

You can use the CONCATENATE function to concatenate strings together.

The function takes an arbitrary number of arguments. All arguments must be strings. Use the TO_TEXT function to convert values of other types (such as number, object, list) to a string.

For example, the following expression produces a value of "$100".

$sys.func.CONCATENATE("$", "100")

CONTAIN

You can use the CONTAIN function to check if a list contains a certain element.

The function takes two arguments:

• the specified list

  Note: If the list is null, the function produces a value of false.

• the value for the existence check

For example, the following expression produces a value of true.

$sys.func.CONTAIN([1, 2, 3], 1)

COUNT

You can use the COUNT function to get the number of elements in a list.

The function takes one argument:

• the list to count

  Note: If the list is null, the function produces a value of 0.

For example, the following expression produces a value of 3.

$sys.func.COUNT([1, 2, 3])

DIVIDE

You can use the DIVIDE function to calculate the quotient of two parameters.

The function takes three arguments:

• the dividend

• the divisor

  Note: Dividing by zero causes an error. The expression is not evaluated and the error message is added to DiagnosticInfo.

• scale - the number of decimal places in the quotient, optional, 3 by default

Examples:

Expression	Result
$sys.func.DIVIDE(10, 2)	5.000
$sys.func.DIVIDE(10, -2)	-5.000
$sys.func.DIVIDE(10, 3, 0)	3
$sys.func.DIVIDE(10.57, 3, 4)	3.5233

FILTER

You can use the FILTER function to filter or extract values from list and composite parameters using syntax from the JsonPath library.

The function takes two arguments:

• the parameter reference in quotes for the list or composite parameter to be filtered.
• a JsonPath expression represented as a string.

You can write an expression that parses values from a list or composite parameter, and this expression can be a path to a nested object that also includes a logical expression for filtering. See JsonPath's documentation for more information on writing JsonPath expressions.

Dialogflow may not support all of the JsonPath operators or functions. See below for examples of operators and expressions that are fully supported.

Consider the following list parameter $session.params.shapes:

    {
      "result": {
        "shapes": [
          {
            "id": 1,
            "shape": "circle",
            "colors": ["red","blue"]
          },
          {
            "id": 2,
            "shape": "square",
            "colors": ["green","orange"]
          },
          {
            "id": 3,
            "colors": "blue"
          }
        ]
      }
    }

Here are examples of extracting elements from the parameter above.

Expression	Result
$sys.func.FILTER("$session.params.shapes", "$.result.shapes[:1]")	[ { "id": 1, "shape": "circle", "colors": [ "red", "blue" ] } ]
$sys.func.FILTER("$session.params.shapes", "$.result.shapes[?(@.colors == 'blue')]")	[ { "id": 3, "colors": "blue" } ]
$sys.func.FILTER("$session.params.shapes", "$.result.shapes[?(@.id < 3 && @.shape != 'square')].colors")	[ [ "red", "blue" ] ]
$sys.func.FILTER("$session.params.shapes", "$.result.shapes[?(@.id > 1 || @.shape == 'circle')].colors")	[ [ "red", "blue" ], [ "green", "orange" ], "blue" ]
$sys.func.FILTER("$session.params.shapes", "$.result.shapes[*].shape")	[ "circle", "square" ]

FORMAT_DATE

You can use the FORMAT_DATE function to represent a date / time using a specified format.

The function takes the following arguments:

• the time that you want to format
• the desired format represented as a string
• (optional) the desired language tag for the output represented as a string

The time (first argument) that you want to format should either be of a time-related entity type (such as @sys.date, @sys.time, and @sys.date-time) or an object with some or all of the following fields:

• year
• month
• day
• hours
• minutes
• seconds
• nanos

For example, the object may look like this:

    {
        "day" : 9,
        "hours": 15,
        "minutes" : 23,
        "month" : 8,
        "nanos" : 0,
        "seconds" : 10,
        "year" : 2021
    }

The format (second argument) you specify should be a string consisting of symbols with the following meanings:

Symbol	Meaning	Examples
y	Year	2021; 21
M	Month of year	06; 6; Jun; June
d	Day of month	10
E	Day of week	Tuesday; Tue; T
a	AM/PM of day	PM
H	Hour in day (0-23)	0
h	Clock hour (1-12)	12
m	Minute of hour	30
s	Secound of minute	59
S	Millisecond	978
z	Time-zone name	Pacific Standard Time; PST

The language (third argument) should be a tag such as en or fr-CA.

The language tag is optional, and if it is unspecified, the output is in English by default, which means the two expressions below are equivalent:

$sys.func.FORMAT_DATE(<time>, <format>)
$sys.func.FORMAT_DATE(<time>, <format>, "en")

If the language tag is invalid, the output is also in English.

For example, if session parameter time is an object representing 8:30AM PST on 2021/06/30, you can generate the following strings representing the time using the FORMAT_DATE function:

$sys.func.FORMAT_DATE($session.params.time, <format>, "en")

Formats	Outputs
"dd/MM/yy"	"30/06/21"
"dd MMM yyyy"	"30 Jun 2021"
"yyyy-MM-dd"	"2021-06-30"
"EEEE, MMMM dd"	"Wednesday, June 30"
"MM-dd h:mm a"	"06-30 8:30 AM"
"hh:mm:ss a, zzzz"	"08:30:00 AM, Pacific Standard Time"
"hh:mm:ss.SSS"	"08:30:00.000"

GET

You can use the GET function to get the value from a list based on an index.

The function takes the following arguments:

• the list to get values

• the index (0-indexed) of the desired value

For example:

Expression	Result
$sys.func.GET([1, 2, 3], 0)	1
$sys.func.GET(["a", "b", "c"], 2)	"c"

If the index specified does not exist within the list, the GET function will return a string containing the full text of the function. When this occurs, the interaction log for this transaction will contain a QueryResult with a SystemFunctionResults and DiagnosticInfo section that states "Index is out of bound."

For example:

Expression	Result
$sys.func.GET([1, 2, 3], 8)	"$sys.func.GET([1, 2, 3], 8)"

This expected behavior can cause runtime issues if the error isn't caught and handled gracefully. This is typically handled by using an IF function to test the validity of the index before issuing the GET function, however this is complicated by the fact that a runtime error in any part of an IF function will render the entire IF function to error. One way to gracefully test for this condition during runtime is to first use a parameter preset to assign the GET function to a parameter and then reference the value of that parameter as one of your IF clauses.

For example:

• Parameter preset:

  Parameter	Value	Result
  __value_a	$sys.func.GET([1, 2, 3], 1)	2
  __value_b	$sys.func.GET([1, 2, 3], 8)	"$sys.func.GET([1, 2, 3], 8)"

• IF evaluation:

  Expression	Result
  $sys.func.IF($sys.func.CONTAIN([1, 2, 3], 1), $session.params.__value_a, 0)	2
  $sys.func.IF($sys.func.CONTAIN([1, 2, 3], 8), $session.params.__value_b, 0)	0

GET_FIELD

You can use the GET_FIELD function to get a value from an object using a key.

The function takes the following arguments:

• the object

• the key of the desired value

For example, if an object $session.params.apple is:

{
  "name" : "apple",
  "color": "red",
}

Expression	Result
$sys.func.GET_FIELD($session.params.apple, "name")	"apple"
$sys.func.GET_FIELD($session.params.apple, "color")	"red"

IDENTITY

The IDENTITY function returns the input argument without any implicit type conversion, which may happen with raw parameter references.

The function takes one argument:

• the value to return

This function is useful for retaining the value type when you reference parameters in the parameter presets Value field.

One example is when you want to reference a parameter that returns a number in the parameter presets Value field and assign this value to a new parameter. To make sure that the new parameter value type is number, set the parameter preset value to $sys.func.IDENTITY($session.params.amount), where amount is the original parameter name.

The following parameter preset configuration sets the new assigned-amount parameter to be the same number value as the amount parameter at runtime:

Parameter	Value
assigned-amount	$sys.func.IDENTITY($session.params.amount)

Another example is when you want to pass a composite object parameter value to a new parameter through parameter presets.

When referencing a composite object parameter that has a field named original (for example, an intent parameter that matches an entity at runtime, in which the original field captures the value written or spoken by the end-user), the default behavior is to return a scalar string that is present in the original field.

For instance, if an object currency-object representing the @sys.unit-currency system entity is:

    {
        "original" : "$400",
        "amount": 400,
        "currency": "USD"
    }

The following parameter preset configuration will set new-currency-object to be "$400" at runtime:

Parameter	Value
new-currency-object	$session.params.currency-object

In some cases, you need the full composite object, rather than the scalar representation, and you can then use the IDENTITY function to help pass the full object.

For example, the following parameter preset configuration will set new-currency-object to be the same object as currency-object at runtime, which contains fields original, amount, and currency:

Parameter	Value
new-currency-object	$sys.func.IDENTITY($session.params.currency-object)

IF

Note: Always wrap the logical condition (first argument) in double quotation marks for best practices.

You can use the IF function to return one of the two values based on a logical condition.

The function takes three arguments:

• the logical expression (whose syntax is the same as the syntax of condition)
• the value to return if the expression is true
• the value to return if the expression is false

For example, the following expression produces a value of 1.

$sys.func.IF("1 < 2", 1, 2)

IS_CREDIT_CARD_NUMBER

Performs a Luhn algorithm check to determine whether the candidate number is a valid card number. Null or empty strings are not valid credit card numbers.

The function takes one argument:

• the credit card number represented as a string

The function returns true if the credit card number provided is valid and false otherwise. For example, true is returned by the function below when provided a Visa test number.

$sys.func.IS_CREDIT_CARD_NUMBER("4111111111111111")

IS_DATE

Validates if a date can be parsed given a date string, date format, and an optional language code. This is for dates that do not reference a time-zone.

The function takes three arguments:

• date string
• date format pattern represented as a string (patterns for formatting and parsing)
• language code represented as a string (optional, defaulting to English) (supports IETF BCP 47 language tags and legacy tags in the IANA Language Subtag Registry)

The function returns true if the date provided is valid and false otherwise. The function will ensure that the day-of-month is valid for the year-month, rejecting invalid values including days that only fall on leap years.

Expression	Result
$sys.func.IS_DATE("2021-04-29", "uuuu-MM-dd")	true
$sys.func.IS_DATE("21 Apr 29", "uu MMM dd")	true
$sys.func.IS_DATE("21 四月 29", "uu MMM dd", "zh-cn")	true
$sys.func.IS_DATE("21 апр 29", "uu MMM dd", "ru")	true
$sys.func.IS_DATE("21 Apr 42", "uu MMM dd")	false
$sys.func.IS_DATE("21 Feb 29", "uu MMM dd")	false

Note: It is important to use "uuuu-MM-dd" over "yyyy-MM-dd" for a date like "2021-04-29". Year is represented by "u" in the pattern and "y" represents year-of-era.

IS_FUTURE_DATE

A function to check if the provided date or datetime is after the current datetime. Both the argument and the current time use the timezone provided in the conversation request. If the timezone is not present in the conversation request, the timezone defined in the agent settings will be used.

The function takes one argument:

• the date or datetime object

The date or datetime object should either be of a date or datetime-related entity type (such as @sys.date, and @sys.date-time) or an object with some or all of the following fields:

• year
• month
• day
• hours
• minutes
• seconds
• nanos

For example, the object may look like this:

    {
        "day" : 16,
        "month" : 5,
        "year" : 2123
    }

Note: A valid date must be provided. For example, May 33, 2023, will return an error. If hour and minute are included, the comparison will be made using date and time, and the second and nano parts will default to 0 if missing. If provided the current date with the hour or minute parts excluded, the function will return false.

For example, if $session.params.your-date = {"year": 2123, "month": 5, "day": 16}, then the following returns true.

$sys.func.IS_FUTURE_DATE($session.params.your-date)

IS_PAST_DATE

A function to check if the provided date or datetime is before the current datetime. Both the argument and the current time use the timezone provided in the conversation request. If the timezone is not present in the conversation request, the timezone defined in the agent settings will be used. A valid date must be provided. For example, May 33, 2023, would return an error.

The function takes one argument:

• the date or datetime object

The date or datetime object should either be of a date or datetime-related entity type (such as @sys.date, and @sys.date-time) or an object with some or all of the following fields:

• year
• month
• day
• hours
• minutes
• seconds
• nanos

For example, the object may look like this:

    {
        "day" : 16,
        "month" : 5,
        "year" : 1989
    }

Note: A valid date must be provided. For example, May 33, 2023, will return an error. If hour and minute are included, the comparison will be made using date and time, and the second and nano parts will default to 0 if missing. If provided the current date with the hour or minute parts excluded, the function will return false.

For example, if $session.params.your-date = {"year": 1989, "month": 5, "day": 16}, then the following returns true.

$sys.func.IS_PAST_DATE($session.params.your-date)

IS_PHONE_NUMBER

Tests whether a phone number can be parsed into a valid number for the given region. Note this doesn't verify the number is actually in use, which is impossible to tell by just looking at a number itself.

The function takes two arguments:

• a phone number represented as a string
• a region code represented as a string (optional)

The function returns true if the phone number provided is valid and false otherwise. For example, if the number is in an international format, prefixed with "+1" for the US and Canada, then Region Code can be excluded. Will default to US region if the number is not prefixed with "+" and the Region Code is not set. Click here for a list of valid ISO-3166 Country Codes.

Expression	Result
$sys.func.IS_PHONE_NUMBER("650-206-5555", "US")	true
$sys.func.IS_PHONE_NUMBER("[phone]")	true
$sys.func.IS_PHONE_NUMBER("2065555")	false

JOIN

You can use the JOIN function to concatenate the elements of a list using a specified delimiter.

If the elements in the list are not strings, the result of the function is equivalent to applying the TO_TEXT function to each element before joining.

The function takes the following arguments:

• the delimiter
• the list to join
• (optional) the final delimiter

For example:

Expression	Result
$sys.func.JOIN(", ", ["a", "b", "c"])	"a, b, c"
$sys.func.JOIN(", ", ["a", "b", "c"], ", and ")	"a, b, and c"

LEN

You can use the LEN function to get the length (number of characters) of a string. Use the TO_TEXT function to convert values of other types (such as number, object, list) to a string.

The function takes one argument:

• the specified string

For example, the following expression produces a value of 6.

$sys.func.LEN("google")

LOWER

You can use the LOWER function to turn a string to lowercase. Use the TO_TEXT function to convert values of other types (such as number, object, list) to a string.

The function takes one argument:

• the string to convert to lowercase

For example, the following expression produces a value of "abc".

$sys.func.LOWER("ABC")

MATCH

You can use the MATCH function to find the index of an element in a list. If a match is found, the index of the first match in the list is returned. If a match is not found, -1 is returned.

The function takes two arguments:

• the list to search
• the element to find

For example, the following expression produces a value of 0.

$sys.func.MATCH([1, 2, 3], 1)

MID

You can use the MID function to get a segment of a string. Use the TO_TEXT function to convert values of other types (such as number, object, list) to a string.

The function takes three arguments:

• the string to extract a segment from
• the starting position of the segment (1-indexed)
• the length (number of characters) of the segment

For example, the following expression produces a value of "gl".

$sys.func.MID("google", 4, 2)

MINUS

You can use the MINUS function to subtract one number from another.

The function takes two arguments:

• the minuend (number to be subtracted from)
• the subtrahend (number to subtract)

For example, the following expression produces a value of 1.

$sys.func.MINUS(3, 2)

MULTIPLY

You can use the MULTIPLY function to calculate the product of an arbitrary number of provided parameters.

The function takes two or more arguments:

• the factor 1
• the factor 2
• the factor 3 (optional)
• ...

Examples:

Expression	Result
$sys.func.MULTIPLY(2, 3)	6
$sys.func.MULTIPLY(2, -4)	-8
$sys.func.MULTIPLY(2.5, 4, 5)	50
$sys.func.MULTIPLY(2.5, 4, 5, 2, -2)	-200

NESTED_FIELD

A function to retrieve a nested value from a composite object or a list within a composite object.

The function takes at least two arguments:

• the name in quotes of the composite parameter which contains the nested value
• one or more keys represented as strings that reference the path to the nested value

For example, if parameter $session.params.your-param-1 = {"a": {"b": "Value"}}

Expression	Result
$sys.func.NESTED_FIELD("$session.params.your-param-1", "a", "b")	"Value"

Note: More than ten levels of nesting is not supported.

This function can be used in the Parameter Preset Form to update a nested value within a composite object or add a new key to a composite object.

For example, if parameter $session.params.your-param-2 = {"a": {"b": 2, "c": [1, 2, 3]}}, you can do the following:

• Update an existing key

  Parameter	Value
  $sys.func.NESTED_FIELD("$session.params.your-param-2", "a", "b")	3

  The updated parameter becomes {"a": {"b": 3, "c": [1, 2, 3]}}.

• Add a new key

  Parameter	Value
  $sys.func.NESTED_FIELD("$session.params.your-param-2", "a", "d")	"new"

  The updated parameter becomes {"a": {"b": 3, "c": [1, 2, 3], "d": "new"}}.

• Update a list value

  Parameter	Value
  $sys.func.NESTED_FIELD("$session.params.your-param-2", "a", "c[0]")	4

  The updated parameter becomes {"a": {"b": 3, "c": [4, 2, 3]}}.

NOW

You can use the NOW function to get the current time.

The function takes no arguments.

For example, the following expression produces an object of @sys.date-time entity type representing the current time. The current time uses the timezone provided in the conversation request. If the timezone is not present in the conversation request, the timezone defined in the agent settings will be used.

$sys.func.NOW()

RAND

Note: The previous name rand remains valid to use.

The function takes no arguments.

You can use the RAND function to generate a random floating point number in the range [0,1), such as in the expression below.

$sys.func.RAND()

REMOVE

You can use the REMOVE function to remove value(s) from a list.

The function takes the following arguments:

• the list to remove values.

  Note: If the list is null, the function produces a value of null.

• an arbitrary number of values to be removed from the list.

  If the value is a list, the values inside the list will be removed one by one.

  All occurrences of the values will be removed from the list.

For example:

Expression	Result
$sys.func.REMOVE([1, 2, 3, 2, 1], 2)	[1, 3, 1]
$sys.func.REMOVE([1, 2, 3], 4)	[1, 2, 3, 4]
$sys.func.REMOVE(["a", "b", "c", "a", "d"], "a", ["b", "c"])	["d"]
$sys.func.REMOVE(null, 1, 2)	null

ROUND

You can use the ROUND function to round a decimal number to a specified number of decimal places.

The function takes 2 arguments:

• the decimal number to round.
• optional number of decimal places. If not specified, the decimal number is rounded to integer.

For example:

Expression	Result
$sys.func.ROUND(10.49)	10
$sys.func.ROUND(10.50)	10
$sys.func.ROUND(10.51)	11
$sys.func.ROUND(10.49, 1)	10.5
$sys.func.ROUND(10.43, 1)	10.4
$sys.func.ROUND(-10.123, 2)	-10.12
$sys.func.ROUND(-10.127, 2)	-10.13

Note: you must use "." as a decimal separator.

SPLIT

You can use the SPLIT function to divide text around a specified character or string and puts the fragments into a list. Use the TO_TEXT function to convert values of other types (such as number, object, list) to a string.

The function takes two arguments:

• the string to split.
• a regular expression that represents the delimiter.

For example, the following expressions both produce a value of ["a", "b", "c"].

$sys.func.SPLIT("a/b/c", "/")
$sys.func.SPLIT("a.b.c", "\.")

To access an element from the returned list, use the GET function.

An example of an expression that produces a value of ["a", "b", "c"] and isolates the first element would be:

$sys.func.GET($sys.func.SPLIT("a.b.c", "\."),0)

If the delimiter does not appear within the string being split, calling $sys.func.SPLIT() will result in a list that contains the original string to split as its only entry.

For example, the following expression produces a value of ["a/b/c"].

$sys.func.SPLIT("a/b/c", "-")

SUBSTITUTE

You can use the SUBSTITUTE function to replace existing text with new text in a string. Use the TO_TEXT function to convert values of other types (such as number, object, list) to a string.

The function takes three arguments:

• the original string
• a regular expression whose matches are replaced
• the text for replacement

For example, the following expressions both produce a value of "google".

$sys.func.SUBSTITUTE("good", "d", "gle")
$sys.func.SUBSTITUTE("goo gl e", "\s+", "")

TO_TEXT

You can use the TO_TEXT function to convert a value of other types (such as a number or a list) to a string.

The function takes one argument:

• the original value to turn into a string form, which can be of any type (e.g. number, list, object)

For example, the following expression produces a value of "3".

$sys.func.TO_TEXT(3)

TO_NUMBER

You can use the TO_NUMBER function to convert a value of other types (such as a string or a boolean) to a number.

The function takes one argument:

• the original value to turn into a number form, which can be type of string, boolean or number.

For example, the following expression produces a value of -3.

$sys.func.TO_NUMBER("-3")

TO_OBJECT

You can use the TO_OBJECT function to convert an arbitrary JSON string to an object.

The function takes one argument:

• The json string representing json object or array. The values in the json can be valid json identifier (numbers, strings, arrays, booleans, objects), or session parameters and function calls.

For example:

$sys.func.TO_OBJECT("{ 'name': '$session.params.username', 'number': 20.48, 'calculation': '$sys.func.ADD($session.params.five, 2.4)', 'inner_object': { 'array': [1, 2, '$session.params.three'] } }")

will produce the following object

{
  name: "User Name",
  number: 20.48,
  calculation: 7.4,
  inner_object: {
    array: [1, 2, 3]
  }
}

You can apply the $sys.func.GET_FIELD function to extract a necessary field from this object.

$sys.func.TO_OBJECT("[{ 'name': 'Charlie', 'age': 20 }, { 'name': 'Alpha', 'age': 30 }]" }]")

[{
  name: 'Charlie',
  age: 20
}, {
  name: 'Alpha',
  age: 30
}]

You can apply the $sys.func.GET function to extract a necessary element from this list.

TO_PHONE_NUMBER

Extract the country code, national destination code, and number from a string phone number.

The function takes two arguments:

• a phone number represented as a string
• a region code represented as a string (optional)

The function returns an object containing the country code, area code, and number. For example, if the number is in an international format, prefixed with "+1" for the US and Canada, then Region Code can be excluded. Will default to US region if the number is not prefixed with "+" and the region code is not set. Click here for a list of valid ISO-3166 Country Codes.

Expression	Result
$sys.func.TO_PHONE_NUMBER("650-206-5555", "US")	{"country-code":"1", "area-code":"650", "number":"2065555"}
$sys.func.TO_PHONE_NUMBER("[phone]")	{"country-code":"49", "area-code":"177", "number":"1783584"}
$sys.func.TO_PHONE_NUMBER("2065555")	{}

UNIQUE

You can use the UNIQUE function to remove duplicates from a list and return a list with distinct elements. The following rules apply:

• The result is deterministic: if there are duplicates in the input list, the first appearance of the element always remains in the list.

• Any input element types, including struct and list, are allowed.

• Null element is ignored and will NOT appear in the result list.

The function takes the following arguments:

• the list to remove duplicates from.

For example:

Expression	Result
$sys.func.UNIQUE([1, 2, 3])	[1, 2, 3]
$sys.func.UNIQUE(["a", "c", "b", "c"])	["a", "c", "b"]
$sys.func.UNIQUE([[3, 2], [3, 2], [3, 1]])	[[3, 2], [3, 1]]
$sys.func.UNIQUE([null, "abc", true, 1.0])	["abc", true, 1.0]

UPPER

You can use the UPPER function to turn a string to uppercase. Use the TO_TEXT function to convert values of other types (such as number, object, list) to a string.

The function takes one argument:

• the string to convert to uppercase

For example, the following expression produces a value of "ABC".

$sys.func.UPPER("abc")

URL_ENCODE

You can use the URL_ENCODE function to URL encode a string. This is useful when calling a webhook with a session parameter that may include specific characters that need to be URL encoded.

The function takes one argument:

• the string to URL encode.

For example, the following expression produces a value of abc%2B%2F%3D.

$sys.func.URL_ENCODE("abc+/=")