Data Mapper

Overview

The Data Mapper node transforms an incoming data object by selecting, renaming, reshaping, and optionally type-casting its fields into a new schema. Use it between integration nodes when the upstream payload structure does not match what a downstream node expects — for example, flattening a nested API response before feeding it into a battle contender input. Unmapped fields are dropped by default; enabling passthrough retains them. If a required source field is missing at runtime, execution is routed to the error output.

Configuration

Field	Type	Required	Description
mappings	array of objects	Yes	Ordered list of field mapping rules. Each rule specifies a source field path (dot-notation), a target field name, an optional type cast (string
passthroughUnmapped	boolean	No	When true, fields not referenced by any mapping rule are copied as-is to the output object. Defaults to false (unmapped fields are dropped).
strictMode	boolean	No	When true, any source field path that cannot be resolved (and has no default) routes execution to the error output instead of silently skipping the field. Defaults to false.
outputRoot	string	No	Optional dot-notation path to nest the entire mapped result under in the output object (e.g. 'payload.data'). Useful when a downstream node expects the result inside a wrapper key.

Inputs

Port	Type	Description
input	object	The source data object to be mapped. Accepts any JSON-serialisable object; nested paths are accessible via dot-notation in mapping rules.

Outputs

Port	Type	Description
output	object	The reshaped object containing only the mapped fields (plus any passthrough fields if enabled), optionally nested under outputRoot.
error	object	Emitted when strictMode is true and a required source path is missing. Carries the original input object and a 'missingFields' array listing each unresolvable path.

Example

{
  "nodeType": "data_mapper",
  "config": {
    "mappings": [
      {
        "source": "response.model.id",
        "target": "modelId",
        "cast": "string"
      },
      {
        "source": "response.model.score",
        "target": "score",
        "cast": "number",
        "default": 0
      },
      {
        "source": "response.meta.finishedAt",
        "target": "completedAt",
        "cast": "string"
      }
    ],
    "passthroughUnmapped": false,
    "strictMode": true,
    "outputRoot": "payload"
  }
}