6. SpatialDDS URIs

6.1 Why SpatialDDS URIs matter

SpatialDDS URIs are the shorthand that lets participants talk about anchors, content, and services without exchanging the full manifests up front. They bridge human concepts—"the anchor in Hall 1" or "the localization service for Midtown"—with machine-readable manifests that deliver the precise data, coordinate frames, and capabilities needed later in the flow.

6.2 Key ingredients

Every SpatialDDS URI names four ideas:

  • Authority – who owns the namespace and keeps the identifiers stable.
  • Zone – a slice of that authority’s catalog, such as a venue, fleet, or logical shard.
  • Type – whether the reference points to an anchor, a bundle of anchors, a piece of content, or a service endpoint.
  • Identifier (with optional version) – the specific record the manifest will describe.

The exact tokens and encoding rules are defined by the individual profiles, but at a glance the URIs read like spatialdds://authority/zone/type/id;v=version. Readers only need to recognize which part expresses ownership, scope, semantics, and revision so they can reason about the rest of the system.

Formal syntax is given in Appendix F.

6.3 Working with SpatialDDS URIs

Once a URI is known, clients ask the authority for the manifest it points to—typically via HTTPS, though authorities can advertise other transports if they operate private caches or field buses. The manifest reveals everything the client needs to act: anchor poses, dependency graphs for experiences, or how to reach a service. Because URIs remain lightweight, they are easy to pass around in tickets, QR codes, or discovery topics while deferring the heavier data fetch until runtime.

6.4 Examples

spatialdds://museum.example.org/hall1/anchor/01J8QDFQX3W9X4CEX39M9ZP6TQ
spatialdds://city.example.net/downtown/service/01HA7M6XVBTF6RWCGN3X05S0SM;v=2024-q2
spatialdds://studio.example.com/stage/content/01HCQF7DGKKB3J8F4AR98MJ6EH

In the manifest samples later in this specification, each of these identifiers expands into a full JSON manifest. Reviewing those examples shows how a single URI flows from a discovery payload, through manifest retrieval, to runtime consumption.