From JSON Schema¶

You already describe the structure of your data with JSON Schema. An OO-LD schema is a JSON Schema, so yours is almost there - you add its meaning:

1. An @context that maps your property names to semantic terms (IRIs). Required at the root of every schema document, even when empty (OOLD-SCH-96a3).
2. A $id that identifies the schema globally (OOLD-VER-3b96).
3. $schema pointing at the OO-LD meta-schema, so OO-LD-aware tools recognize the dialect.

The first two are what the meta-schema requires of a document; without either, validation fails.

Before - a plain JSON Schema:

{
  "title": "Minimal",
  "type": "object",
  "properties": {
    "name": { "type": "string", "description": "Name of the thing" }
  }
}

After - the same schema as OO-LD:

{
  "$schema": "https://oo-ld.org/latest/meta/oold-meta-schema.json",
  "$id": "Minimal.schema.json",
  "@context": {
    "schema": "http://schema.org/",
    "name": "schema:name"
  },
  "title": "Minimal",
  "type": "object",
  "properties": {
    "name": { "type": "string", "description": "Name of the thing" }
  }
}

$schema: https://oo-ld.org/latest/meta/oold-meta-schema.json
$id: Minimal.schema.json
'@context':
  schema: http://schema.org/
  name: schema:name
title: Minimal
type: object
properties:
  name:
    type: string
    description: Name of the thing

Your existing JSON Schema validators keep working unchanged: @context and every x-oold-* keyword are extension keywords that generic 2020-12 validators ignore. Keep JSON keys tool-friendly by aliasing (name -> schema:name) instead of using IRIs as property names.

Next steps¶

• Basic Concepts - how one document is both a schema and a context.
• Composition - assemble types from reusable building blocks.