JSON Transform

Overview

The JSON Transform node applies a jq-style or template expression to reshape, filter, or extract fields from an incoming JSON object. Use it to normalize data between workflow steps, project only the fields a downstream node expects, or construct new objects from existing values. If the expression is invalid or the input does not match the expected shape, execution routes to the error output rather than halting the workflow. No external credentials are required.

Configuration

Field	Type	Required	Description
expression	string	Yes	A jq-style or template expression applied to the input object. Examples: .results[0].score, {id: .battle_id, score: .metrics.score}.
expressionLanguage	enum	No	Selects the expression dialect. Options: jq (default) or template. Use template for simple string interpolation; use jq for full structural transforms.
outputKey	string	No	When set, wraps the transform result under this key in the output object instead of replacing the root. Useful when merging results into the existing context.
strict	boolean	No	When true, routes to the error output if the expression yields null or undefined. Defaults to false, which passes null through the output port.

Inputs

Port	Type	Description
input	object	The JSON object to transform. Any valid JSON object from a prior workflow step.

Outputs

Port	Type	Description
output	object	The transformed JSON object produced by the expression.
error	object	Emitted when the expression fails to parse, throws at runtime, or strict mode is enabled and the result is null. Contains message and expression fields.

Example

{
  "nodeType": "json_transform",
  "config": {
    "expression": "{battleId: .battle_id, winner: .result.winner, finalScore: .result.scores.total}",
    "expressionLanguage": "jq",
    "outputKey": "summary",
    "strict": true
  }
}