Scope, architecture, and validation¶
Package structure and storage¶
The distribution is pystac-ext-product; the import path is pystac.extensions.product. The wheel excludes the shared pystac.extensions initializer owned by PySTAC.
ProductExtension.ext() selects a wrapper that mutates the existing PySTAC object:
| Object | Storage | Extension declaration |
|---|---|---|
| Item | properties |
Item stac_extensions |
| Collection | extra_fields |
Collection stac_extensions |
| Asset | extra_fields |
Owner stac_extensions |
| ItemAssetDefinition | properties |
Owner Collection stac_extensions |
Asset wrappers additionally read owning Item properties as a fallback. They do not fall back to Collection fields. Item asset definitions have no fallback. Removing an Asset override can reveal the Item value again.
ProductExtension.summaries() accesses Collection summary lists independently of top-level fields. It does not aggregate Items or truncate lists to one entry. Catalogs and Links are not supported by ext().
Validation boundaries¶
The wrapper stores product metadata; it does not deliver products or calculate their timeliness. Its main dependency check requires timeliness when setting a category. See the field reference for precise setter and apply() behavior.
Neither apply() nor to_dict() performs JSON Schema validation. For full validation, install python -m pip install "pystac[validation]" and call item.validate() or collection.validate(). Schema retrieval can require network access unless your application configures a local validator.
The wrapper declares Product v1.1.0. Schema validation checks enum values and unique summary entries in addition to field constraints. An inherited Item duration may satisfy an Asset wrapper's category check, while schema validation still requires a duration in the Asset's own fields.
Migration hooks¶
PRODUCT_EXTENSION_HOOKS exposes the schema identifier, the previous v1.0.0 identifier, the legacy identifier product, and supported Item/Collection object types. The module does not automatically register this object with PySTAC. During PySTAC migration, the hook replaces recognized previous identifiers with v1.1.0. Registering the hook alone does not force migration of a document already using the current STAC core version. Field contents are preserved, including deprecated qualitydegraded; choose any replacement lifecycle status explicitly.