Nested objects

Use Nested for children defined inline and Template to reference another saved template.

Inline object

Child fields belong in the field's nested array:

{
  "name": "address",
  "type": "Nested",
  "options": {"array": false, "quantity": 1},
  "nested": [
    {"name":"city","type":"City"},
    {"name":"country","type":"Country"}
  ]
}

Set array: true and an integer quantity to produce a repeated structure. Review the resulting JSON before delivering it to an API; the receiving system determines whether it expects an object, array or wrapper such as an OData results property.

Saved template reference

{
  "name": "line_items",
  "type": "Template",
  "options": {"templateId":"<line-item-template-id>","array":true,"quantity":3}
}

The option is templateId, not template_id. Use foreignKey when the child needs to inherit a key from the enclosing record. The referenced child's field name must match that key. Generate a multi-row sample to confirm parent and child IDs agree.

Circular template references are skipped to break cycles. Do not rely on a self-reference plus a max_depth option to produce recursive trees; build a bounded tree explicitly in a scenario.

Derived fields and dependencies

A Derived field can interpolate another field with options.value: "{{first_name}} {{last_name}}". Expression mode uses the supported expression language, not arbitrary JavaScript or JSONPath. Dependencies determine generation order, so inspect validation errors for unknown references and cycles instead of trying to fix them only by moving rows in the editor.

For transformations across separate datasets or complex cross-record coordination, use a mapping plan or scenario.