Scope, architecture, and validation¶

Package structure¶

The distribution is pystac-ext-osc. Import OSC wrappers from pystac.extensions.osc and the record adapter from pystac.extensions.ogc_record. The wheel excludes the shared namespace initializer owned by PySTAC.

OscExtension.ext() chooses a Catalog, Collection, or Item wrapper. It writes directly into the object's existing metadata dictionary. It does not register an .ext.osc accessor. OSC_EXTENSION_HOOKS declares the v1.0.0 schema, no previous extension identifiers, and Catalog/Collection/Item types; registration with a migration system is left to callers.

The published OSC v1.0.0 schema and upstream main schema were compared on 2026-10-06 and were identical. The implemented project/product field set matches them. Source: OSC specification.

OGC Records and STAC¶

OGCRecord subclasses pystac.Item to reuse links, assets, and compatible extension wrappers. It initializes STACObject directly to allow records without a STAC datetime. This dependency on PySTAC's object internals warrants testing when upgrading PySTAC.

Default serialization produces a Record GeoJSON Feature. STAC declarations and assets are preserved as foreign members when supplied. Use OGCRecord.from_dict() explicitly: ordinary PySTAC dispatch does not distinguish arbitrary records from STAC Items. to_stac_item() is an explicit conversion requiring a STAC instant or both interval endpoints. OGC time is independent and is never converted automatically.

Validation boundaries¶

Neither OSC apply methods nor serialization runs JSON Schema validation. Apply methods mutate fields sequentially and clear omitted optional values. They do not provide transactional updates or create related links.

For STAC validation, install pystac[validation] and call the STAC object's validate(). Schema retrieval may require network access or an application-configured schema cache.

OGCRecord.from_dict() checks basic Feature structure, not full OGC conformance. The metadata accessors expose dictionaries and do not validate nested schemas. record.validate(validator) requires an explicit object exposing validate(document), configured for the OGC schema and references. Calling it without a validator raises ValueError. For STAC validation use record.to_stac_item().validate().

The adapter is an in-memory document interface, not an OGC API server, search client, or conformance certification. See OGC Record reference.