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name: serialization description: "Serialize GeoDjango geometries and model instances as GeoJSON-compatible Geometry, Feature, or FeatureCollection data with validated input, IDs, properties, bboxes, precision, deduplication, transforms, and automatic field mapping." disable-model-invocation: true metadata: disco-role: operating license: MIT

Serialization

Use this skill when a DRF endpoint must read or write GeoJSON geometry values or emit GeoJSON Feature / FeatureCollection objects. Start with references/api-reference.md for exact public names, defaults, output shape, and validation messages. Use references/workflows.md for complete serializer recipes and references/troubleshooting.md when GeoDjango, geometry parsing, SRIDs, fields, or null/empty values fail.

Route the request

• Use GeometryField for a model geometry field or a plain serializer geometry value. Configure precision, remove_duplicates, auto_bbox, and transform only when the representation needs them.
• Use GeometrySerializerMethodField when a serializer method computes the geometry. Return a GEOSGeometry or None.
• Use GeoFeatureModelSerializer for one GeoJSON Feature; pass many=True for a FeatureCollection. Set Meta.geo_field explicitly, including None for a geometry-less model, and choose id_field, properties, and bbox behavior deliberately.
• Use get_properties() and unformat_geojson() together when the GeoJSON properties object is not the model's ordinary serializer fields.
• Put query predicates in spatial-filtering, pagination and OpenAPI behavior in pagination-and-schema, and database, native-test, and backend setup in integration-testing.

Operating sequence

1. Install rest_framework_gis after rest_framework in INSTALLED_APPS so its app config registers GeoDjango fields with DRF's ModelSerializer mapping. An explicitly declared GeometryField works without relying on automatic mapping.
2. For plain geometry input, accept a GeoJSON dictionary, WKT/EWKT/HEXEWKB string, or GEOSGeometry; send a JSON string when a multipart form cannot carry a nested dictionary.
3. For feature input, send properties plus optional geometry, id, and writable bbox. A partial update may omit geometry; DRF then retains the instance value.
4. Verify output as JSON-compatible data and test SRID transforms and spatial database behavior in the target environment. GEOS parsing alone does not prove ORM or PostGIS execution.

The deterministic, database-free smoke check is linked from references/workflows.md. From the runtime skill root, run:

python sub-skills/serialization/scripts/geometry_smoke.py --help
python sub-skills/serialization/scripts/geometry_smoke.py