Core

4.1. Context Composition

A compact UJG JSON-LD document MUST include the Core JSON-LD context.

A specification that defines compact terms not defined by Core MUST normatively identify the published URL of the JSON-LD context that defines those terms.

A compact UJG JSON-LD document that uses terms not defined by Core MUST compose the Core context with the published contexts that define those terms.

When a compact UJG JSON-LD document uses terms not defined by Core, its @context MUST reference the published URLs of the contexts that define those terms.

Specifications or deployments MAY publish convenience aggregate contexts that compose the Core context with additional contexts, but such aggregate contexts are outside the scope of Core.

A composed context is expressed as a JSON-LD @context array in which the Core context appears together with one or more additional contexts required by the document and published at https://ujg.specs.openuji.org/ed/ns/context.jsonld

{
  "@context": [
    "https://ujg.specs.openuji.org/ed/ns/core.context.jsonld",
    "https://ujg.specs.openuji.org/ed/ns/graph.context.jsonld",
    "https://ujg.specs.openuji.org/ed/ns/runtime.context.jsonld",
    "https://ujg.specs.openuji.org/ed/ns/experience.context.jsonld"
  ]
}

{
  "@context": [
    "https://ujg.specs.openuji.org/ed/ns/core.context.jsonld",
    "https://ujg.specs.openuji.org/ed/ns/graph.context.jsonld",
    "https://ujg.specs.openuji.org/ed/ns/runtime.context.jsonld",
    "https://ujg.specs.openuji.org/ed/ns/experience.context.jsonld"
  ]
}

4.2. Extensions

extensions MAY appear on any Node.

extensions MUST NOT appear on UJGDocument.

If present, extensions MUST be a JSON object.

Each top-level key in extensions MUST be a namespace string controlled by the extension author. Authors SHOULD use reverse-DNS names or URI-based identifiers.

Each top-level value in extensions MUST be a JSON object.

Consumers MUST preserve unknown extension entries during read-transform-write unless operating in an explicitly lossy mode.

Consumers MUST NOT let unknown extensions affect core identity, import resolution, or reference resolution.

Consumers MAY apply namespace-specific processing for recognized extensions.

Extensions that change core graph meaning SHOULD be standardized as first-class UJG modules rather than hidden inside extensions.

4.3. Import Resolution

imports values MUST be IRI references.

An imports value MAY be an absolute IRI or a relative IRI reference.

Relative import references MUST be resolved against the location of the importing UJGDocument.

For a document retrieved via HTTP(S), the base for resolution is the document URL. For a document loaded from a file URL, the base for resolution is the file URL of the importing document.

Core does not define a manifest root, package root, or workspace root for import resolution.

If no stable document location is available, relative imports are implementation-specific and may not be portable.

6.1. Minimal Document

{
  "@context": "https://ujg.specs.openuji.org/ed/ns/core.context.jsonld",
  "@id": "https://example.com/ujg/core/minimal.jsonld",
  "@type": "UJGDocument",
  "specVersion": "1.0"
}

{
  "@context": "https://ujg.specs.openuji.org/ed/ns/core.context.jsonld",
  "@id": "https://example.com/ujg/core/minimal.jsonld",
  "@type": "UJGDocument",
  "specVersion": "1.0"
}

6.2. Document With Relative Imports

{
  "@context": "https://ujg.specs.openuji.org/ed/ns/core.context.jsonld",
  "@id": "https://example.com/ujg/flows/order/main.jsonld",
  "@type": "UJGDocument",
  "specVersion": "1.0",
  "imports": [
    "./shared/states.jsonld",
    "../runtime/events.jsonld",
    "https://example.com/ujg/common/errors.jsonld"
  ]
}

{
  "@context": "https://ujg.specs.openuji.org/ed/ns/core.context.jsonld",
  "@id": "https://example.com/ujg/flows/order/main.jsonld",
  "@type": "UJGDocument",
  "specVersion": "1.0",
  "imports": [
    "./shared/states.jsonld",
    "../runtime/events.jsonld",
    "https://example.com/ujg/common/errors.jsonld"
  ]
}

Resolved imports:

• ./shared/states.jsonld → https://example.com/ujg/flows/order/shared/states.jsonld

• ../runtime/events.jsonld → https://example.com/ujg/flows/runtime/events.jsonld

• https://example.com/ujg/common/errors.jsonld → unchanged

This follows [RFC3986] relative-reference resolution and the [JSON-LD 1.1.] rule that relative IRI references resolve from the document base IRI.

6.3. Document With Nodes

{
  "@context": "https://ujg.specs.openuji.org/ed/ns/core.context.jsonld",
  "@id": "https://example.com/ujg/core/nodes.jsonld",
  "@type": "UJGDocument",
  "specVersion": "1.0",
  "nodes": [
    {
      "@id": "urn:ujg:node:alpha",
      "@type": "Node"
    },
    {
      "@id": "urn:ujg:node:beta",
      "@type": "Node",
      "extensions": {
        "com.example.audit": {
          "checksum": "sha256:abc123"
        }
      }
    }
  ]
}

{
  "@context": "https://ujg.specs.openuji.org/ed/ns/core.context.jsonld",
  "@id": "https://example.com/ujg/core/nodes.jsonld",
  "@type": "UJGDocument",
  "specVersion": "1.0",
  "nodes": [
    {
      "@id": "urn:ujg:node:alpha",
      "@type": "Node"
    },
    {
      "@id": "urn:ujg:node:beta",
      "@type": "Node",
      "extensions": {
        "com.example.audit": {
          "checksum": "sha256:abc123"
        }
      }
    }
  ]
}