FEEL Reference

FEEL (Friendly Enough Expression Language) is the expression language used in Conduit for gateway conditions, script tasks, decision table input entries, and decision table output entries.

Input Entry Syntax (Unary Tests)

Input cells in decision tables use unary tests — each cell is tested against the column’s input value. Only a subset of FEEL is allowed here.

Entry	Matches when
`-`	Any value (always passes)
(blank)	Same as `-`
`42`	Value equals 42
`> n`	Greater than n
`< n`	Less than n
`>= n`	Greater than or equal to n
`<= n`	Less than or equal to n
`!= n`	Not equal to n
`[a..b]`	Inclusive range: a ≤ x ≤ b
`(a..b)`	Exclusive range: a < x < b
`[a..b)`	Half-open: a ≤ x < b
`(a..b]`	Half-open: a < x ≤ b
`"string"`	String equals “string” (exact)
`"x","y"`	Value is any of x or y (OR)
`not("x","y")`	Value is neither x nor y
`true`	Boolean true
`false`	Boolean false
`null`	Value is null
`date("2024-01-01")`	Date literal

Operator Reference (Gateway Conditions & Script Tasks)

Full FEEL is available in gateway conditions, script tasks, and output entries.

Comparison operators

Operator	Meaning
`=`	Equality (not `==`)
`!=`	Inequality
`<`, `>`	Less than, greater than
`<=`, `>=`	Less than or equal, greater than or equal

Boolean operators

Operator	Example
`and`	`amount > 0 and status = "active"`
`or`	`tier = "gold" or tier = "platinum"`
`not(expr)`	`not(status = "closed")`

Context literals (Script Task output)

{ fee: amount * 0.05, tier: if amount > 1000 then "premium" else "standard" }

Each key is written as a separate process variable.

Conditionals

if amount > 1000 then "premium" else "standard"

Built-in Functions

Numeric

Function	Description
`abs(n)`	Absolute value
`floor(n)`	Round down to nearest integer
`ceiling(n)`	Round up to nearest integer
`decimal(n, scale)`	Round n to scale decimal places
`modulo(n, d)`	Remainder of n ÷ d
`sqrt(n)`	Square root

String

Function	Description
`string length(s)`	Length of string
`upper case(s)`	Convert to uppercase
`lower case(s)`	Convert to lowercase
`substring(s, start)`	Substring from position (1-based)
`substring(s, start, len)`	Substring with length
`contains(s, sub)`	True if s contains sub
`starts with(s, pre)`	True if s starts with pre
`ends with(s, suf)`	True if s ends with suf
`matches(s, pattern)`	True if s matches regex pattern
`replace(s, pattern, rep)`	Replace regex matches
`string join(list)`	Join list elements into a string
`string join(list, sep)`	Join with separator

List

Function	Description
`count(list)`	Number of elements
`min(list)`	Minimum value
`max(list)`	Maximum value
`sum(list)`	Sum of all values
`mean(list)`	Arithmetic mean
`list contains(list, item)`	True if list contains item
`append(list, item)`	New list with item appended
`flatten(list)`	Flatten nested lists one level
`distinct values(list)`	Remove duplicates
`reverse(list)`	Reversed list
`sort(list, fn)`	Sort with comparator function
`sublist(list, start)`	Sublist from position
`sublist(list, start, len)`	Sublist with length
`union(list1, list2)`	Merge two lists, deduplicated

Date and Time

Function	Description
`now()`	Current date and time
`today()`	Current date
`date("2024-01-01")`	Parse date literal
`time("12:00:00")`	Parse time literal
`date and time("2024-01-01T12:00:00Z")`	Parse datetime literal
`duration("P1D")`	Parse ISO 8601 duration

Context

Function	Description
`get value(context, key)`	Get a value from a context by key
`get entries(context)`	Get list of `{ key, value }` pairs
`context(entries)`	Build a context from a list of key-value pairs

Conversion

Function	Description
`string(value)`	Convert to string
`number(s)`	Parse string to number
`not(bool)`	Negate a boolean

Examples

-- Gateway condition: route high-value orders
amount > 1000 and tier = "gold"

-- Script task: enrich order
{ fee: amount * 0.05, tier: if amount > 1000 then "premium" else "standard", itemCount: count(items) }

-- Decision table output: compute label
if score >= 90 then "excellent" else if score >= 70 then "good" else "needs improvement"

-- String manipulation
upper case(substring(customerId, 1, 3))

-- Date comparison
date(orderDate) < today()