Data and transforms

These blocks work on values already in the run: lists, objects, text, numbers and dates. They don’t touch the outside world. This page documents 19 blocks. For how flows work, see Flows and the flow editor. Values in settings can use templates such as {{ input.id }} and {{ steps.load.output.email }}; see Block reference overview.

Block	What it does
Hash	Hashes text with SHA-256, or signs it with HMAC-SHA256 using a secret.
Parse JSON	Parses a JSON string.
Stringify JSON	Serialises a value as JSON text.
Calculate	Arithmetic on numbers: add, subtract, multiply, divide, round, min, max, sum.
Current time	The current UTC time, optionally shifted.
Batch list	Splits a list into bounded batches for downstream processing.
Filter list	Keeps list items matching a policy-style condition.
Flatten list	Flattens nested lists by a selected number of levels.
Group list	Groups a list into an object keyed by a field or dotted path.
Transform	Applies an inline or Python transformer to a value.
Pick fields	Keeps only some keys of an object.
Rename fields	Renames top-level fields on an object or every object in a list.
Slice list	Selects a window of a list for paging or limiting results.
Sort list	Sorts a list by a field or dotted path.
Summarize list	Summarizes a list, optionally once per group.
Template	Builds a value from a template (strings, objects or lists).
Remove duplicates	Removes duplicate list items, optionally using a field or dotted path.
Generate id	Generates a UUID4 or a random URL-safe token.
Validate	Validates a value against field definitions. Fails with 422 or follows `invalid`.

Hash

Key: crypto.hash Hashes text with SHA-256, or signs it with HMAC-SHA256 using a secret. Continues to: next

Setting	Type	Required	Default	Notes
`text`	text	yes
`algorithm`	`sha256 \| sha512 \| hmac-sha256`		`sha256`
`secret`	text			Secret name, for HMAC

Parse JSON

Key: json.parse Parses a JSON string. Continues to: next

Setting	Type	Required	Default	Notes
`text`	text	yes

Stringify JSON

Key: json.stringify Serialises a value as JSON text. Continues to: next

Setting	Type	Required	Default	Notes
`value`	any JSON	yes
`indent`	whole number

Calculate

Key: math.calculate Arithmetic on numbers: add, subtract, multiply, divide, round, min, max, sum. Continues to: next

Setting	Type	Required	Default	Notes
`operation`	`add \| subtract \| multiply \| divide \| round \| min \| max \| sum \| average`	yes
`values`	any JSON	yes		List of numbers
`digits`	whole number		`2`

Current time

Key: time.now The current UTC time, optionally shifted. Continues to: next

Setting	Type	Required	Default	Notes
`offset_seconds`	whole number		`0`
`format`	`iso \| date \| unix`		`iso`	iso: 2026-09-28T08:00:00+00:00 · date: 2026-09-28 · unix: seconds

Batch list

Key: transform.batch Splits a list into bounded batches for downstream processing. Continues to: next

Setting	Type	Required	Default	Notes
`value`	any JSON	yes
`size`	whole number	yes		1 to 1000

Key: transform.filter Keeps list items matching a policy-style condition. Continues to: next

Setting	Type	Required	Default	Notes
`value`	any JSON	yes
`condition`	any JSON	yes		Use $item and$ index to inspect each list item

Flatten list

Key: transform.flatten Flattens nested lists by a selected number of levels. Continues to: next

Setting	Type	Required	Default	Notes
`value`	any JSON	yes
`depth`	whole number		`1`	1 to 20

Group list

Key: transform.group Groups a list into an object keyed by a field or dotted path. Continues to: next

Setting	Type	Required	Default	Notes
`value`	any JSON	yes
`field`	text	yes

Transform

Key: transform.map Applies an inline or Python transformer to a value. Continues to: next

Setting	Type	Required	Default	Notes
`value`	any JSON	yes
`transformer`	any JSON	yes		The reshaping steps: omit, pick, set, rename and case

Pick fields

Key: transform.pick Keeps only some keys of an object. Continues to: next

Setting	Type	Required	Default	Notes
`value`	any JSON	yes
`fields`	list of string	yes

Rename fields

Key: transform.rename Renames top-level fields on an object or every object in a list. Continues to: next

Setting	Type	Required	Default	Notes
`value`	any JSON	yes
`fields`	any JSON	yes		Map old field names to new field names

Slice list

Key: transform.slice Selects a window of a list for paging or limiting results. Continues to: next

Setting	Type	Required	Default	Notes
`value`	any JSON	yes
`offset`	whole number		`0`
`limit`	whole number			Maximum number of items

Sort list

Key: transform.sort Sorts a list by a field or dotted path. Continues to: next

Setting	Type	Required	Default
`value`	any JSON	yes
`field`	text	yes
`descending`	yes / no		no

Summarize list

Key: transform.summarize Summarizes a list, optionally once per group. Continues to: next

Setting	Type	Required	Default	Notes
`value`	any JSON	yes
`operation`	`count \| count_distinct \| sum \| average \| min \| max \| median \| mode \| first \| last \| collect \| distinct`	yes		The aggregation to calculate
`field`	text			Field or dotted path to summarize
`group_by`	text			Field or dotted path to group by
`ignore_null`	yes / no		yes

Template

Key: transform.template Builds a value from a template (strings, objects or lists). Continues to: next

Setting	Type	Required	Default	Notes
`template`	any JSON	yes

Remove duplicates

Key: transform.unique Removes duplicate list items, optionally using a field or dotted path. Continues to: next

Setting	Type	Required	Default	Notes
`value`	any JSON	yes
`field`	text			Field or dotted path used to identify duplicates

Generate id

Key: util.id Generates a UUID4 or a random URL-safe token. Continues to: next

Setting	Type	Required	Default	Notes
`kind`	`uuid \| token`		`uuid`
`length`	whole number		`32`

Validate

Key: validate.schema Validates a value against field definitions. Fails with 422 or follows invalid. Continues to: next, invalid (follow the one that applies)

Setting	Type	Required	Default	Notes
`value`	any JSON	yes
`fields`	any JSON	yes		Field definitions
`on_invalid`	`fail \| branch`		`fail`

​Hash

​Parse JSON

​Stringify JSON

​Calculate

​Current time

​Batch list

​Filter list

​Flatten list

​Group list

​Transform

​Pick fields

​Rename fields

​Slice list

​Sort list

​Summarize list

​Template

​Remove duplicates

​Generate id

​Validate