Build a CityJSON 2.0 Building Extension Schema Inspector

Inspect municipal CityJSON 2.0 models using custom extensions to verify taxation and historic status attributes. Validate custom object types and attribute bindings against official extension specs.

City Data Governance Analyst

Ingest CityJSON 2.0 city models containing custom extension declarations in the extensions dictionary.

Inspect CityObjects for extended types prefixed with '+' and verify attribute schema rules.

Validate transform matrices and vertex coordinate bounds against declared geographical extents.

Generate a schema conformance report identifying unregistered extension fields or malformed types.

A terminal CLI and web report viewer displaying schema conformance errors, extension definitions, and line numbers.

Construct small synthetic CityJSON files containing valid and invalid '+' extended attributes using standard JSON mocks. Starter examples below are synthetic. They are not downloaded records.

CityJSON Leverages CityJSON Section 1 (extensions object) and Section 2 ('+' prefixed extended types) specifications.

semantic-kernel, python, jsonschema. Provides modular integration plugins for JSON Schema validation and natural language error explanation. Instruction-following LLM to parse schema mismatches and output remediation recommendations.

Submit runnable source, pinned dependencies, setup commands, a working interface, example outputs, and a recorded end-to-end demo. Include tests and an action log.

Verifies that all '+' prefixed extended types match an entry in the extensions block.

Flags missing geographicalExtent arrays on first-level CityObjects.

Emits clear validation status and actionable field error paths.

```json [ { "input": { "type": "CityJSON", "version": "2.0", "extensions": { "HeritageTax": { "url": "https://example.gov/schemas/v1/heritagetax.json", "version": "1.0" } }, "CityObjects": { "BLDG-701": { "type": "+HeritageBuilding", "geographicalExtent": [ 10, 20, 0, 30, 40, 15 ], "attributes": { "+taxDistrict": "Historic_Core", "+preservationTier": 1 } } } }, "expected_output": { "status": "VALID", "registered_extensions": [ "HeritageTax" ], "extended_objects_count": 1, "schema_errors": [] } }, { "input": { "type": "CityJSON", "version": "2.0", "extensions": {}, "CityObjects": { "BLDG-999": { "type": "+UnregisteredExtensionBuilding", "attributes": { "yearBuilt": 1910 } } } }, "expected_output": { "status": "INVALID", "registered_extensions": [], "extended_objects_count": 1, "schema_errors": [ { "object_id": "BLDG-999", "error": "Type '+UnregisteredExtensionBuilding' used without corresponding entry in extensions object", "path": "CityObjects.BLDG-999.type" }, { "object_id": "BLDG-999", "error": "Missing geographicalExtent member on 1st-level CityObject", "path": "CityObjects.BLDG-999.geographicalExtent" } ] } } ] ```

Read-only syntax verification tool with no write privileges to municipal cadastre systems. Use mock external writes. Require human review before any real deployment.