Fields

The types and the modifiers, on one invoice. customer, assignee, and parent are ref fields, and each says what happens on delete: restrict, nullify, or cascade. ssn is pii, so the platform treats it as personal data. net is computed from the two money fields. age_days carries its own check.

app billing "Billing" {}

entity Account {
  name: text required
}

entity Invoice "Invoice" plural "Invoices" {
  number:     text required label "Number"
  customer:   ref Account on delete restrict
  assignee:   ref Account on delete nullify
  parent:     ref Invoice on delete cascade
  issued_on:  date
  due_at:     datetime
  active:     boolean
  total:      money USD
  terms:      longtext help "Shown on the printed invoice."
  ssn:        text pii hidden
  attachment: file
  status:     enum draft, sent, paid
  discount:   money USD
  net:        computed number = total - discount
  notes:      json
  age_days:   number validate age_days >= 0 "Age cannot be negative."
}