JMESPath

Both admin UI and runners have custom functions added to standard JMESPath library

The following functions can be used in addition to specification provided by JMESPath language, to support common use cases:

Implementation Domain

Server Side

These functions are available wherever JMESPath expressions are used by runners (e.g. transform steps, input/output patterns).

Client Side

These functions are available in conditional display, eval value widget, table editor pattern cells as well as name & icon field definitions of listers. They are not supported in other JMESPath use cases.

Batch

These functions are available wherever JMESPath expressions are used by Python runners and libraries (e.g. ML training steps, python event handlers).

Customization on the client side includes async functions, which are not applicable for certain use cases, which is why these functions are not used in all UI elements.

Some functions are only available on batch, client or server side, which are marked as follows:

[C]: Available on Client-Side.

[S]: Available on Server-Side.

[B]: Available on Batch.

Unmarked: Available on all.

Server-side JMESPath implementation returns null when the input node is null, regardless of the expression provided (including constant value expressions), due to Java JMESPath library implementation logic.

This applies to all areas where JMESPath is used (i.e. transform steps, event input and output patterns).

Functions

Arrays

Merge arrays

Signature: add_all(left: array, right: array) -> array Parameters:

• left (array, required): First array.

• right (array, required): Second array.

Merges left and right and returns a new array.

Cartesian product

Signature: cartesian(lists: array) -> array Parameters:

• lists (array, required): Array of arrays.

Creates the cartesian product of lists.

Distinct values

Availability: [S, C] Signature: distinct(values: array) -> array Parameters:

• values (array, required): Input array.

Returns distinct values in values.

Read array element by index

Availability: [S, C] Signature: element_at(list: array, index: number) -> any Parameters:

• list (array, required): Input array.

• index (number, required): Index to read.

Returns the element at index.

Group array

Availability: [S, C] Signature: group_by(list: array, field: string) -> array Parameters:

• list (array, required): Input array.

• field (string, required): Field to group by.

Groups entries and returns [{ id: "", list: [] }].

Add index to array entries

Signature: index_array(list: array, field: string="index", start: number=0) -> array Parameters:

• list (array, required): Array of objects.

• field (string, default: "index"): Field name to add.

• start (number, default: 0): Start index.

Adds an index field to each entry in list.

Array intersection

Availability: [S, C] Signature: intersect(left: array, right: array) -> array Parameters:

• left (array, required): First array.

• right (array, required): Second array.

Returns the intersection of left and right.

Remove array entries

Signature: remove_all(list: array, toRemove: array) -> array Parameters:

• list (array, required): Input array.

• toRemove (array, required): Values to remove.

Removes all entries of toRemove from list.

Repeat object template

Signature: repeat(template: object, list: array, keyField: string) -> array Parameters:

• template (object, required): Base object to repeat.

• list (array, required): Array of values or objects to merge in.

• keyField (string, required): Field name to use when merging scalar entries.

Repeats template for each entry of list.

Chunk array

Availability: [S] Signature: split_array(list: array, size: number) -> array Parameters:

• list (array, required): Input array.

• size (number, required): Max chunk size.

Splits list into a list of arrays, each up to size entries.

Merge arrays by index

Signature: merge_index(left: array, right: array, leftField: string=null, rightField: string=null) -> array Parameters:

• left (array, required): First array.

• right (array, required): Second array.

• leftField (string, default: null): Field to nest left entry into.

• rightField (string, default: null): Field to nest right entry into.

Merges two arrays by index.

If leftField and rightField are set, entries are nested under those fields. Otherwise, fields are merged (spread) into a single entry.

Objects & paths

Deep merge objects

Signature: deep_merge(...objects: object) -> object Parameters:

• objects (object, required): One or more objects.

Deep merges nested objects. Use merge() for shallow merges.

Deep diff

Availability: [S] Signature: deep_diff(oldValue: any, newValue: any) -> array Parameters:

• oldValue (any, required): Old record.

• newValue (any, required): New record.

Returns a nested list of differences with "old" vs "new" values.

Key/value to object

Availability: [S, C] Signature: k_vtoo(key: string, value: any) -> object Parameters:

• key (string, required): Key to use.

• value (any, required): Value to assign.

Converts (key, value) to an object.

List to object

Signature: ltoo(pairs: array, keyField: string) -> object Parameters:

• pairs (array, required): Array of key-value objects.

• keyField (string, required): Field name holding the key.

Converts a list of key-value pairs into an object.

Object to list

Signature: otol(obj: object, keyField: string, valueField: string) -> array Parameters:

• obj (object, required): Input object.

• keyField (string, required): Field name to use for keys.

• valueField (string, required): Field name to use for values.

Converts an object to a list of key-value pairs.

Read object element by path

Availability: [S, C] Signature: get_element(obj: object, path: string) -> any Parameters:

• obj (object, required): Object to read from.

• path (string, required): JSON path string.

Returns element at path.

Set object element by path

Signature: set_element(obj: object, path: string, value: any) -> object Parameters:

• obj (object, required): Object to update.

• path (string, required): JSON path to write.

• value (any, required): Value to set.

Adds/sets value at path.

Remove object fields

Availability: [S, C] Signature: remove_elements(obj: object, fields: array) -> object Parameters:

• obj (object, required): Object to modify.

• fields (array, required): Array of field names (strings) to remove.

Removes all listed fields from obj.

Remove null fields

Availability: [S, C] Signature: remove_nulls(obj: object, removeEmptyStrings: boolean=false) -> object Parameters:

• obj (object, required): Object to clean.

• removeEmptyStrings (boolean, default: false): Also remove empty string values.

Removes null fields from obj. Optionally removes empty strings too.

Find JSON paths by regex

Availability: [S] Signature: find_paths(input: any, regex: string) -> array Parameters:

• input (any, required): Record to search.

• regex (string, required): Regex to match against JSON paths.

Searches all JSON paths in input and returns matching paths.

Value type

Availability: [S, C] Signature: type(value: any) -> string Parameters:

• value (any, required): Input value.

Returns type of value: OBJECT, ARRAY, NUMBER, STRING, BOOLEAN, NULL.

Dynamic expressions

Evaluate dynamic expression

Availability: [S, C] Signature: dynamic(input: any, expr: string) -> any Parameters:

• input (any, required): Input object passed to the expression.

• expr (string, required): JMESPath expression as a string.

Evaluates expr against input.

Map with dynamic expression

Availability: [S, C] Signature: dynamic_repeat(input: any, list: array, expr: string) -> array Parameters:

• input (any, required): Passed as input.

• list (array, required): Iteration list. Each entry is passed as entry.

• expr (string, required): JMESPath expression string.

Evaluates expr for each {input, entry} and returns the results as an array.

Filter with dynamic expression

Availability: [S, C] Signature: dynamic_filter(input: any, list: array, expr: string) -> array Parameters:

• input (any, required): Passed as input.

• list (array, required): Array to filter. Each entry is passed as entry.

• expr (string, required): Expression returning a boolean.

Filters list using the boolean result of expr for each {input, entry}

Strings & text

Replace substring

Signature: replace(text: string, search: string, replacement: string) -> string Parameters:

• text (string, required): Input string.

• search (string, required): Substring to replace.

• replacement (string, required): Replacement substring.

Replaces occurrences of search with replacement in text.

Split string

Signature: split(text: string, delimiter: string) -> array Parameters:

• text (string, required): Input string.

• delimiter (string, required): Delimiter.

Splits text by delimiter.

Substring

Signature: substr(text: string, start: number, end: number=null) -> string Parameters:

• text (string, required): Input string.

• start (number, required): Start index (0-based).

• end (number, default: null): End index (exclusive). When null, returns to end.

Returns a substring of text.

Trim whitespace

Availability: [S, C] Signature: trim(value: string) -> string Parameters:

• value (string, required): Input string.

Returns trimmed value.

Lowercase

Availability: [S, C] Signature: to_lower(value: string) -> string Parameters:

• value (string, required): Input string.

Lowercases value.

Uppercase

Availability: [S, C] Signature: to_upper(value: string) -> string Parameters:

• value (string, required): Input string.

Uppercases value.

Slugify

Signature: slug(text: string, transliterate: boolean=false) -> string Parameters:

• text (string, required): Input string.

• transliterate (boolean, default: false): Use transliteration when true.

Converts text to a slug. It trims, lowercases, normalizes/transliterates, removes non-ASCII letters, replaces non-alphanumerics with -, and trims -.

URL encode

Availability: [S, C] Signature: encode_url(value: string) -> string Parameters:

• value (string, required): Plain text.

URL-encodes value.

URL decode

Availability: [S, C] Signature: decode_url(value: string) -> string Parameters:

• value (string, required): URL-encoded text.

Decodes URL-encoded text.

Base64 encode

Signature: btoa(value: any) -> string Parameters:

• value (any, required): Value to encode.

Encodes value into a base64 string.

Base64 decode

Signature: atob(value: string) -> string Parameters:

• value (string, required): Base64-encoded string.

Decodes value from base64 and returns UTF-8 text.

Regex match

Availability: [C, B] Signature: regex(value: string, pattern: string) -> any Parameters:

• value (string, required): Input string.

• pattern (string, required): Regex pattern.

Returns regex match result for value.

JSON & CSV

JSON parse

Availability: [S, C] Signature: to_json(value: string) -> any Parameters:

• value (string, required): JSON text.

Parses JSON text into an object/array.

JSON stringify

Availability: [S, C] Signature: from_json(value: any) -> string Parameters:

• value (any, required): JSON object or array.

Converts a JSON object/array into a string.

Parse CSV

Availability: [S] Signature: csv_to_json(csv: string, options: object=null) -> array Parameters:

• csv (string, required): CSV input text.

• options (object, default: null): CSV parsing options. Uses Apache Commons CSV CSVFormat.

Parses CSV text into an array of records.

Print CSV

Availability: [S] Signature: json_to_csv(records: array, options: object=null) -> string Parameters:

• records (array, required): Array to print.

• options (object, default: null): Printing options. Uses Apache Commons CSV CSVFormat.

Prints records as CSV text.

Date & time

Current time

Signature: now() -> number

Returns current time in epoch milliseconds.

Format date

Signature: date_to_string(epochMs: number, pattern: string="MM-dd-yyyy") -> string Parameters:

• epochMs (number, required): Epoch time in milliseconds.

• pattern (string, default: "MM-dd-yyyy"): Java date format pattern.

Formats epochMs using pattern.

Parse date

Signature: string_to_date(value: string, pattern: string="MM-dd-yyyy") -> number Parameters:

• value (string, required): Date text.

• pattern (string, default: "MM-dd-yyyy"): Java date format pattern.

Parses value into epoch milliseconds.

Cron time helper

Availability: [S] Signature: cron(pattern: string, action: string, timeZone: string, epochMs: number) -> number | boolean Parameters:

• pattern (string, required): Cron pattern.

• action (string, required): One of last, next, fromLast, toNext, match.

• timeZone (string, default: "SYSTEM"): Time zone ID. Use "SYSTEM" for server time zone.

• epochMs (number, required): Epoch time in milliseconds.

Processes pattern relative to epochMs using timeZone.

• last: epoch ms for last match before epochMs.

• next: epoch ms for next match after epochMs.

• fromLast: milliseconds since last match.

• toNext: milliseconds until next match.

• match: whether the pattern matches the given time.

Crypto & hashing

Encrypt text

Availability: [S] Signature: encrypt(plainText: string, key: string, algorithm: string="AES/ECB/PKCS5Padding", keyAlgorithm: string="AES") -> string Parameters:

• plainText (string, required): Plain text.

• key (string, required): Encryption key.

• algorithm (string, default: "AES/ECB/PKCS5Padding"): Cipher algorithm.

• keyAlgorithm (string, default: "AES"): Key algorithm.

Encrypts plainText using key.

AES/ECB/PKCS5Padding is not recommended for high-security use cases. Use a stronger mode.

For structured payloads, pair this with to_json() / from_json().

Decrypt text

Availability: [S] Signature: decrypt(cipherText: string, key: string, algorithm: string="AES/ECB/PKCS5Padding", keyAlgorithm: string="AES") -> string Parameters:

• cipherText (string, required): Encrypted text.

• key (string, required): Encryption key.

• algorithm (string, default: "AES/ECB/PKCS5Padding"): Cipher algorithm.

• keyAlgorithm (string, default: "AES"): Key algorithm.

Decrypts cipherText using key.

AES/ECB/PKCS5Padding is not recommended for high-security use cases. Use a stronger mode.

Hash text

Availability: [S] Signature: hash(plainText: string, key: string, algorithm: string="SHA-256", iterations: number=1) -> string Parameters:

• plainText (string, required): Plain text to hash.

• key (string, required): Key/salt string.

• algorithm (string, default: "SHA-256"): Hash algorithm.

• iterations (number, default: 1): Iteration count.

Hashes plainText using key.

Validate hash

Availability: [S] Signature: validate_hash(plainText: string, hashedText: string, key: string, algorithm: string="SHA-256", iterations: number=1) -> boolean Parameters:

• plainText (string, required): Plain text to verify.

• hashedText (string, required): Hashed string to compare against.

• key (string, required): Key/salt string.

• algorithm (string, default: "SHA-256"): Hash algorithm.

• iterations (number, default: 1): Iteration count.

Validates plainText against hashedText.

Generate random key

Availability: [S, C] Signature: salt_key(length: number) -> string Parameters:

• length (number, required): Desired length.

Creates a secure random key string of length characters.

Lookup & joins

Lookup / join

Signatures:

• Availability: [S, B] lookup(left: array, right: array, key: string, full: boolean=false) -> array

• Availability: [C] lookup(source: string, id: string) -> any

Join arrays ([S, B]) Joins left and right on field key.

• full=false performs a left join.

• full=true performs a full join.

Client-side source lookup ([C]) Looks up a record by id from a configured source.

Client-side lookup() is only available in evaluation providers (not in Handlebars templates).

It is not implemented server-side to avoid unintended access to sensitive states.

Math & logic

Compare values

Availability: [S, C] Signature: compare(left: any, right: any) -> number Parameters:

• left (any, required): First value.

• right (any, required): Second value.

Returns 0 if equal, -1 if left < right, 1 if left > right.

Conditional value

Availability: [S, C] Signature: cond(test: boolean, ifTrue: any, ifFalse: any) -> any Parameters:

• test (boolean, required): Condition to evaluate.

• ifTrue (any, required): Value to return if test is true.

• ifFalse (any, required): Value to return if test is false.

Returns ifTrue or ifFalse based on test.

Divide numbers

Signature: divide(dividend: number, divisor: number) -> number | null Parameters:

• dividend (number, required): Numerator.

• divisor (number, required): Denominator.

Divides dividend by divisor. Returns null if divisor is 0.

Multiply numbers

Signature: multiply(left: number, right: number) -> number Parameters:

• left (number, required): First factor.

• right (number, required): Second factor.

Returns left * right.

Modulo

Signature: mod(value: number, base: number) -> number Parameters:

• value (number, required): Input number.

• base (number, required): Base.

Returns value % base.

Power

Signature: power(value: number, exponent: number) -> number Parameters:

• value (number, required): Base.

• exponent (number, required): Exponent.

Returns value ^ exponent.

Negate number

Signature: minus(value: number) -> number Parameters:

• value (number, required): Input number.

Returns -value.

To integer

Availability: [S, C] Signature: to_int(value: number) -> number Parameters:

• value (number, required): Input number.

Returns the integer part of value (floor-like). Returns an int value.

IDs & randomness

Generate GUID

Availability: [S, C] Signature: guid() -> string

Creates and returns a globally unique ID string.

Generate UUID

Availability: [S, C] Signature: uuid() -> string

Creates a universally unique ID value.

Random integer

Availability: [S, C] Signature: rand(min: number, max: number) -> number Parameters:

• min (number, required): Minimum integer.

• max (number, required): Maximum integer.

Returns a random integer between min and max.

Environment

Read environment variable

Availability: [S] Signature: get_env(name: string) -> string | null Parameters:

• name (string, required): Environment variable name.

Returns the environment variable value. Intended for server-side use only.