Inactive Fields

Fields can be inactive through static flags or dynamic conditions.

{
  id: "admin_notes",
  kind: "text",
  label: "Admin notes",
  hiddenWhen: { kind: "field-value", field: "mode", notEquals: "review" }
}

State Meaning

State	User can see it	User can edit it	Default submission behavior
hidden	No	No	Omitted when inactive.
disabled	Usually yes	No	Omitted when inactive.
readOnly	Yes	No	Included unless also hidden or disabled.

The kit default is inactiveFieldPolicy: "omit". That keeps backend payloads focused on active user choices.

Use inactiveFieldPolicy: "include" when the backend must receive the full state snapshot.

mountForm(container, {
  transport: createJsonTransport({ endpoint: "/api/predict" }),
  schema,
  inactiveFieldPolicy: "include",
});

Practical Guidance

• Use hiddenWhen for branch-specific fields.
• Use disabledWhen when the user should understand why a value is unavailable.
• Use readOnlyWhen for review mode or locked data.
• Keep backend validation aligned with the chosen inactive field policy.