For AI agents: the complete documentation index is available at https://a3s-lab.github.io/UI/v0.4.1/en/llms.txt, the full documentation bundle is available at https://a3s-lab.github.io/UI/v0.4.1/en/llms-full.txt, and this page is available as Markdown at https://a3s-lab.github.io/UI/v0.4.1/en/components/form-system/schema-profile-1.md.

Schema Profile 1

The next compiler requires a3s.dev/form-schema-profile/1. This is a closed subset of JSON Schema 2020-12: the headless runtime, browser adapters, Compiler Worker, CLI, and fixed-digest workflow validation all use the same semantics. Behavior outside the profile fails compilation.

Supported features

AreaSupported features
Core$schema, $id, type, title, description, default, enum, const
Objectsproperties, required, and boolean or Schema-form additionalProperties
Arraysitems, minItems, maxItems, structural uniqueItems
StringsminLength, maxLength, Unicode pattern, and approved format values
Numbersminimum, maximum, and positive multipleOf values

Approved formats are email, uri, date, date-time, time, hostname, ipv4, ipv6, and uuid.

multipleOf controls both numeric validation and the step of native number inputs. Decimal multiples use a tolerance comparison, so multipleOf: 0.1 correctly accepts 0.3.

Profile 1 does not accept $ref, Schema combinators, conditional Schemas, tuple Schemas, or unevaluated-property keywords. The compiler does not silently ignore them; it reports schema.keyword.unsupported with the exact JSON Pointer.

Every successfully compiled FormPlan contains:

{
  "apiVersion": "a3s.dev/form-plan/v1alpha1",
  "schemaProfile": "a3s.dev/form-schema-profile/1"
}

See the Profile 1 specification for value semantics, exclusions, and complete examples.