Intrinsic functions¶

Intrinsic functions transform payload values inside a state definition, without calling out to a task. They are available in JSONPath query-language mode, in fields whose name ends with .$:

"Parameters": {
  "greeting.$": "States.Format('Hello, {}!', $.name)",
  "id.$": "States.UUID()"
}

In JSONata mode you use JSONata expressions instead of intrinsic functions. See JSONata.

Referencing data¶

In JSONPath mode, a string value references runtime data by its prefix:

$ / $.path: The state input. $ is the whole input; $.order.id selects a path within it.
$$.path: The context object, for example $$.Execution.Id, $$.State.Name or $$.State.EnteredTime.
$name: A variable set earlier with Assign, for example $customer or $customer.email.

An intrinsic function's arguments may be literals, input paths ($, $.…) or context paths ($$.…). Assigned variables ($name) can be used in ordinary JSONPath fields, but are not resolved inside intrinsic-function arguments. This differs from AWS and is a known limitation.

Available functions¶

Stegflow implements the 18 standard Amazon States Language intrinsics.

States.Array(value, ...): Builds an array from the given values.
States.ArrayContains(array, value): Returns true if array contains value.
States.ArrayGetItem(array, index): Returns the element at zero-based index.
States.ArrayLength(array): Returns the number of elements in array.
States.ArrayPartition(array, chunkSize): Splits array into chunks of chunkSize.
States.ArrayRange(start, end, step): Builds an array of numbers from start to end by step.
States.ArrayUnique(array): Removes duplicate elements from array.
States.Base64Encode(string): Encodes string to Base64.
States.Base64Decode(base64): Decodes a Base64 string.
States.Format(template, value, ...): Replaces each {} placeholder in template with the given values.
States.Hash(data, algorithm): Hashes data. algorithm is one of MD5, SHA-1, SHA-256, SHA-384, SHA-512.
States.JsonMerge(json1, json2, isDeep): Merges two objects. isDeep is a boolean: false for a shallow merge, true for a deep merge.
States.JsonToString(path): Serializes the value at path to a JSON string.
States.MathAdd(num1, num2): Returns num1 + num2.
States.MathRandom(start, end): Returns a random integer between start and end. An optional third argument seeds the generator for reproducible values.
States.StringSplit(string, delimiter): Splits string on delimiter into an array.
States.StringToJson(string): Parses a JSON string into a value.
States.UUID(): Returns a version 4 UUID.

Examples¶

{
  "chunks.$": "States.ArrayPartition($.items, 10)",
  "checksum.$": "States.Hash($.payload, 'SHA-256')",
  "merged.$": "States.JsonMerge($.defaults, $.overrides, false)",
  "roll.$": "States.MathRandom(1, 6)",
  "parts.$": "States.StringSplit('a,b,c', ',')"
}

Functions can be nested, and their arguments may be literals or JSONPath references into the state input.