transforms

transforms is the list of processing nodes in a pipeline, executed in declaration order. Each node has a name and one or more processing fields.

Node Types

filter — Row Filtering

transforms:
  - name: active-only
    filter: "record.status == 'active' && record.deleted_at == null"

• Uses a CEL expression; rows not satisfying the condition are discarded
• Compiled + type-checked at validate time (not evaluated)
• record is the current row object

js — JavaScript Transform

transforms:
  - name: enrich
    js: |
      record.tier = record.spend > 1000 ? 'premium' : 'standard';
      record.processed_at = new Date().toISOString();
      return record;   // null = discard this row

• GraalVM JS runtime (same process as Java; no subprocess overhead)
• return null = discard this row
• Returning an array = one row becomes multiple rows (fan-out)

rename — Field Renaming

transforms:
  - name: normalize-fields
    rename:
      user_id: id
      created_at: createdAt
      full_name: name

typeFilter — Filter by Data Type

transforms:
  - name: only-inserts
    type_filter: insert    # insert | update | delete

Retains only CDC events of the specified operation type.

unwind — Array Flattening

transforms:
  - name: flatten-tags
    unwind: tags           # array field name

Flattens an array field: one record → N records (N = array length).

nest — Master-Detail Merge (Beta)

transforms:
  - name: embed-orders
    nest:
      into: users
      from: orders
      by: user_id
      as: orders           # embedded field name
      mode: array          # array | object

Caution

nest is available in the Beta phase; not included in POC/Alpha.

Node Combination Example

transforms:
  - name: filter-active
    filter: "record.status == 'active'"

  - name: normalize
    rename:
      user_id: id
      created_at: createdAt

  - name: enrich
    js: |
      record.tier = record.spend > 1000 ? 'premium' : 'standard';
      return record;

Nodes execute in order; the output of each node is the input to the next.