Contexts

Every JSON-LD-derived source declares the terms and aliases it uses in its own context, so the same file keeps its meaning in another JSON-LD tool.

Supported contexts

Context	Use
Dollar keyword aliases	$id, $type, $reverse, and the other JSON-LD keyword aliases
A relative .jsonld or .yamlld path	Project-specific terms kept under the served directory

The dollar-keyword URL identifies a bundled context. sparqld uses its local copy and never requests it over the network. Put that URL in a document's @context when using dollar aliases.

Relative contexts resolve from the source's directory. They may also use @import to reference another relative context. Every referenced file must remain inside the directory served by sparqld.

When a local context changes, sparqld reloads every source that reaches it through @context or @import.

Local context files

Use a relative path in @context for a context stored beside a source or in a subdirectory. A file named context.jsonld or context.yamlld is ordinary: it is used only when a document explicitly names it. JSON-LD context files use an @context member; YAML-LD context files express the same structure in YAML 1.2. Like other recognized files, context files are also loaded as source graphs.

The Alpha Centauri source and its context.yamlld file live in the same directory. The context defines the terms used by the source; the source names that context explicitly:

context.yamlldalpha-centauri.yamlld

"@context":
  schema: https://schema.org/
  dbo: http://dbpedia.org/ontology/
  dbp: http://dbpedia.org/property/
  dbr: http://dbpedia.org/resource/
  xsd: http://www.w3.org/2001/XMLSchema#
  name: schema:name
  description: schema:description
  subjectOf:
    "@id": schema:subjectOf
    "@type": "@id"
  constellation:
    "@id": dbo:constellation
    "@type": "@id"
  discovered:
    "@id": dbp:discovered
    "@type": xsd:date
  star:
    "@id": dbp:star
    "@type": "@id"

"@context":
  - https://json-ld.org/contexts/dollar-convenience.jsonld
  - context.yamlld
$id: dbr:Alpha_Centauri
$type: dbo:Star
name: Alpha Centauri
description: >-
  The closest star system to the Solar System.
constellation: dbr:Centaurus

Context access

Other absolute URLs are rejected. sparqld does not fetch contexts from the web, and a relative path cannot escape the served directory. This keeps a dataset reproducible and prevents a context change elsewhere from changing its meaning.