JSON-LD schema export

agrag.schema.formats.to_jsonld(schema, *, base_iri=None) returns a Python dictionary with a JSON-LD representation of the schema's OWL vocabulary. The exporter has no optional dependency.

The output describes schema terms. It does not contain graph instance data, and the export does not make an OWL reasoner part of extraction. OWL vocabulary does not enforce the extraction patterns that GraphSchema uses.

Call the exporter

Pass a GraphSchema to to_jsonld. Use load_schema to create one from the canonical dictionary form:

import json

from agrag.schema import load_schema
from agrag.schema.formats import to_jsonld

schema = load_schema(
    {
        "name": "catalog",
        "version": "1",
        "entities": [
            {"label": "Product", "description": "A catalog item."},
            {"label": "Supplier", "description": "A product supplier."},
        ],
        "relations": [
            {
                "label": "SUPPLIES",
                "description": "A supplier provides a product.",
                "patterns": [["Supplier", "Product"]],
            }
        ],
    }
)

print(json.dumps(to_jsonld(schema), indent=2))

Namespace

Without base_iri, the exporter uses urn:agrag:schema:<encoded-name>: as the base namespace. It percent-encodes the schema name for use in the namespace. Pass base_iri to use a different base namespace.

document = to_jsonld(schema, base_iri="https://example.org/catalog#")

base_iri applies to the exported vocabulary. It does not change the schema name or version.

Mapping

Schema declaration	JSON-LD vocabulary
Entity type	owl:Class, with rdfs:label and a description in rdfs:comment
Parents	rdfs:subClassOf links to each declared parent
Entity property	owl:DatatypeProperty, with its entity type as the domain
Property type	xsd:string, xsd:integer, xsd:double, xsd:boolean, or xsd:date
Relation	owl:ObjectProperty, with endpoint alternatives in owl:unionOf when needed
Maximum one target per source	owl:FunctionalProperty
Maximum one source per target	owl:InverseFunctionalProperty
Larger relation limits	agrag:maxPerSource and agrag:maxPerTarget integer annotations
Relation pattern pairs	agrag:patterns, with each pair stored as a JSON string
Symmetry	agrag:symmetric boolean annotation
Property required flag and enum	agrag:required and agrag:enum annotations

The agrag prefix names https://ontogr.com/agrag/schema#. The annotations preserve declarations for tools that understand them; OWL reasoners do not enforce them. Symmetry is an annotation rather than an owl:SymmetricProperty axiom, so OWL reasoners do not infer reverse edges from the export.

Entity and relation IRIs append the percent-encoded label to the base. Property IRIs append the separately percent-encoded entity label and property name, separated by /, so slash-containing names cannot make distinct declarations share an IRI. Parent links use standard OWL inheritance. In OWL, a child therefore also belongs to a parent's property domain, although GraphSchema does not inherit property declarations.

Domain and range unions do not preserve the pairing between endpoint types. For example, patterns (Person, Company) and (Team, Project) produce domain and range unions that also admit the other pairings. Symmetric relations include both endpoints in both unions because each allowed edge can also be reversed. Read agrag:patterns for the original pairs. A relation with no patterns has no domain or range axiom.

The export omits the schema version. It does not validate base_iri; pass an absolute namespace IRI, usually ending in #, /, or :. OWL functional properties express identity constraints, not data validation rules that reject a second value.

For the schema input formats and canonical dictionary fields, see Schema file format. For a walkthrough of defining a schema, see Define a graph schema.