Open vs hosted

Run it yourself. The candidate specification is published for open review; the reference resolver, SDKs, schemas, and conformance tooling are Apache-2.0. You can ingest or register existing observations/records, resolve identities, and serve their state, relationships, representations, provenance, and lifecycle data with no hosting account or fee.

Or use a hosted resolver. Operating a resolver and registry across parties is a hosting and operations service. A hosted deployment can provide persistence, availability, access control, and optional enrichment; it does not replace perception, detection, localization, geometric registration, rendering, navigation, or grasp planning.

4D-ID is a candidate standard until adopted. Current conformance is limited to 15 schema-level checks passing; functional work continues. Hosting and operational services are separate from the open implementation tools.