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Set node

Set Node

Overview

The Set Node reshapes payloads by adding, updating, or removing fields in flight. It supports both click-to-configure field mappings and JSON-based templates, allowing teams to enrich data, normalize schemas, or inject metadata without writing custom code. Expressions are fully supported so downstream nodes receive the exact structure and values they expect.

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Core Functionality

1. Two Authoring Modes

• Manual mode lets you configure individual fields with dedicated names, values, and target types.
• JSON mode accepts a JSON structure (including expressions) that merges into the payload.

2. Expression-Aware Transformations

• Any string field can include Maestro expressions ({{ }}) that resolve against pipeline context.
• Expressions have access to $input, $node, $trigger and $execution.

3. Type Conversion & Validation

• Supported target types: string (the default for a new field), number, boolean, json, auto.
• A value that can't be converted to its field's type fails the node, naming the field. Use auto to accept any value: it turns text that looks like a number, true/false or JSON into that type, and keeps everything else as it is.
• Validation catches missing field names, unsupported types, or invalid JSON before execution.

4. Flexible Input Merge Strategies

• Include Input Data: "all" (default) clones the inbound payload before applying changes.
• Include Input Data: "none" starts from an empty object—ideal for building new payloads.
• Include Input Data: "selected" is reserved for selective merges; today it behaves like "all" unless the backend injects filtered data.

5. Field-Level Controls

• Keep Only Set Fields removes fields not explicitly configured (manual mode only).
• Dot notation (user.profile.name) creates or updates nested objects when Support Dot Notation is enabled.

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Configuration Reference

Parameters

Parameter	Type	Default	Required	Description
Mode	select	"manual"	No	manual: Define fields individually. json: Provide a complete JSON structure.
Fields	array	[]	If manual	Array of field definitions (name, value, type).
JSON Data	string	""	If json	JSON structure with embedded {{ }} expressions.
Keep Only Set	boolean	false	No	Remove all fields from input except the ones explicitly set.
Support Dot Notation	boolean	true	No	Enable nested field access with dot notation.
Include Input Data	select	"all"	No	all / none / selected -- Which input fields to keep.

Manual Field Definition (fields[])

Property	Type	Description
Name	string	Target field name; supports dot notation when enabled.
Value	string	Literal value or expression resolved at runtime.
Type	select	Conversion target: string (default), number, boolean, json, auto.

Settings

Setting	Options	Default	Description
Timeout (seconds)	number	Pipeline default	Maximum execution time for this node (1--600).
Retry on Timeout	Pipeline Default / Enabled / Disabled	Pipeline Default	Whether to retry on timeout.
Retry on Fail	Pipeline Default / Enabled / Disabled	Pipeline Default	Whether to retry on failure. When Enabled, shows Advanced Retry Configuration.
On Error	Pipeline Default / Stop Pipeline / Continue Execution	Pipeline Default	Behavior when node fails after all retries.

Advanced Retry Configuration

Only visible when Retry on Fail is set to Enabled.

Field	Type	Default	Range	Description
Max Attempts	number	3	1--10	Maximum retry attempts.
Initial Delay (ms)	number	1000	100--30,000	Wait before first retry.
Max Delay (ms)	number	120000	1,000--300,000	Upper bound for backoff delay.
Multiplier	number	2.0	1.0--5.0	Exponential backoff multiplier.
Jitter Factor	number	0.1	0--0.5	Random jitter.

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Usage Examples

Example 1: Add Production Metadata in Manual Mode

Field	Value
Mode	manual
Include Input Data	all
Support Dot Notation	true
Description	Attach operator name and processed timestamp.

Manual Field	Assigned Value	Type
batch.operatorName	Jane Miller	string
batch.processedAt	1706539200000	number

The incoming payload is preserved while the node adds a nested batch object with operator details.

Example 2: Build a Fresh Payload with JSON Mode

Field	Value
Mode	json
JSON Data	{"status":"ready","line":"Assembly-1","targetUnits":480}
Include Input Data	none

The output becomes exactly the JSON object above—ideal for shaping requests to a downstream connector without carrying legacy fields.

Example 3: Keep Only Essential Fields

Field	Value
Mode	manual
Include Input Data	all
Keep Only Set	true
Description	Return only identifiers for audit export.

Manual Field	Assigned Value	Type
orderId	PO-8721	string
totalAmount	1543.75	number
metadata.retryCount	0	number

After execution, the payload contains only the configured fields: orderId, totalAmount and a nested metadata.retryCount set to 0. Every other input field is dropped.

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Configuration reference

The fields below are generated from the node's config contract, so they match what the pipeline validator enforces and what the designer's form offers.

transform.set

Field	Type	Required	Default	Values	Description
mode	string	no	manual	manual, json	manual sets the entries of fields one by one; json parses jsonData as an object and merges its keys into the output
fields	object[]	no	—	—	Fields to set when mode is manual, applied in order; ignored in json mode. Names must be unique — the output has one slot per name. With no entries the input passes through unchanged
jsonData	string	no	—	accepts an expression	A JSON object as a string, with {{ }} expressions resolved before it is parsed; required when mode is json and ignored otherwise. Its keys are merged into the output
keepOnlySet	boolean	no	false	—	true emits only the fields this node sets; false starts from the input data (per includeInputData) and sets the fields on top of it
supportDotNotation	boolean	no	true	—	true treats a dot in a field name as a nested path (user.name sets output.user.name, creating objects on the way); false uses the whole name as one literal key
includeInputData	string	no	all	all, none, selected	all starts the output from a copy of the input; none starts from an empty object. selected is accepted for saved configs but behaves as all — there is no field selection. Ignored when keepOnlySet is true