CityJSON Validator

CityJSON Validator processes CityJSON documents to verify structural compliance with the CityJSON schema, correct object hierarchies, and consistent geometry. It parses the JSON, validates top-level properties, and confirms versioning, CRS usage, and domain-specific constraints. The tool reports invalid objects, missing required fields, and inconsistent indices, enabling targeted fixes.
Conceptually, it performs schema validation, geometric coherence checks (such as valid MultiSurface geometries, non-self-intersecting faces, and bounding box presence), and topology-like verifications for object references. The validator supports multiple CityJSON versions and can operate in strict or lenient modes to accommodate incomplete datasets encountered in exchanges.
Outputs include machine-readable error lists and human-readable summaries suitable for pipelines and QA documentation. Unique differentiators include deep geometry validation beyond basic JSON schema, arity checks on properties, and compatibility reporting for downstream tools used in GIS, web visualization, and simulation workflows.
Typical use cases include pre-import QA for large city models, CI integration for data pipelines, and auditing legacy datasets before archiving or distribution. The tool is designed for data engineers, GIS analysts, urban planners, and developers integrating CityJSON into automated workflows, data catalogs, or web services.