The model¶

Ontophora models the OWL 2 structural specification as a set of independent records. A construct record owns its fields; relationships between records are UID references instead of nested Pydantic models.

Records and references¶

Every construct inherits uid and kind from BaseConstruct. uid is a normalized hexadecimal identifier such as 0x2a. kind is a fixed OWL construct name such as Class, SubClassOf, or ObjectSomeValuesFrom.

A field that points at another construct has the type Reference[T]. At runtime, it becomes a ReferenceValue containing only the target UID. The generic parameter supplies expected-kind metadata for schema inspection, but Ontophora deliberately does not resolve the UID or verify that a complete record set contains it. A package owner can therefore load, stream, index, or validate records in the order that fits its system.

The registry is authoritative¶

The registry contains every concrete model and derives the package-wide discriminated union from it. That one catalog drives construct_types, coerce_construct, and construct_json_schema. Adding support for a construct means adding its model and registering its metadata, not teaching several separate lists about it.

Metadata also records OWL's abstract categories. For example, Class belongs to Entity and ClassExpression; SubClassOf belongs to Axiom and ClassAxiom. Some constructs are marked as blank nodes because they represent anonymous expressions rather than IRI-identified entities.

Stable serialization and fingerprints¶

OWL has both ordered and unordered fields. Models use lists where order carries meaning and sets where it does not. The base model serializes set values in a stable order so a model's JSON representation is repeatable.

Fingerprinting goes further: it hashes an acyclic record's content after replacing each known reference with the referenced record's fingerprint. The result ignores the record's own UID, so independently assigned identifiers do not make equal content appear different. References outside the supplied index remain UID references. Canonical fingerprints for cyclic record graphs are not yet supported.