{
  "$id": "https://schemas.openchronology.org/index.json",
  "title": "OpenChronology Schema Registry",
  "description": "Root index for the OpenChronology JSON Schema registry. Lists all published and pre-release spec versions with their schema base URLs. Implementers and tools may fetch this file to discover available versions and locate schemas for a given spec version.",
  "openchronology": {
    "project": "OpenChronology",
    "home": "https://openchronology.org",
    "github": "https://github.com/knoj/openchronology",
    "license": "CC-BY-4.0",
    "registry_base": "https://schemas.openchronology.org/",
    "contact": "https://openchronology.org/working-group"
  },
  "latest_stable": null,
  "latest_prerelease": "0.3",
  "versions": [
    {
      "version": "0.2",
      "status": "pre-release",
      "published": "2026-05",
      "base_url": "https://schemas.openchronology.org/v0.2/",
      "index_url": "https://schemas.openchronology.org/v0.2/index.json",
      "schemas": {
        "core": "https://schemas.openchronology.org/v0.2/core.schema.json",
        "full": "https://schemas.openchronology.org/v0.2/full.schema.json",
        "calendar": "https://schemas.openchronology.org/v0.2/calendar.schema.json",
        "universe": "https://schemas.openchronology.org/v0.2/universe.schema.json",
        "manifest": "https://schemas.openchronology.org/v0.2/manifest.schema.json",
        "stream": "https://schemas.openchronology.org/v0.2/stream.schema.json"
      },
      "notes": "First published schema set. Complete pre-release draft covering all file types in the v0.2 spec. Not yet recommended for production use \u2014 breaking changes possible before 1.0."
    },
    {
      "version": "0.3",
      "status": "pre-release",
      "published": "2026-05",
      "base_url": "https://schemas.openchronology.org/v0.3/",
      "index_url": "https://schemas.openchronology.org/v0.3/index.json",
      "schemas": {
        "core": "https://schemas.openchronology.org/v0.3/core.schema.json",
        "full": "https://schemas.openchronology.org/v0.3/full.schema.json",
        "calendar": "https://schemas.openchronology.org/v0.3/calendar.schema.json",
        "universe": "https://schemas.openchronology.org/v0.3/universe.schema.json",
        "manifest": "https://schemas.openchronology.org/v0.3/manifest.schema.json",
        "stream": "https://schemas.openchronology.org/v0.3/stream.schema.json"
      },
      "notes": "Adds content.sources for external citations. Expands significance metrics vocabulary. Documents built-in bodies. Fixes relations to require target_id."
    }
  ],
  "versioning_policy": {
    "summary": "Same MAJOR version = compatible. Parsers MUST ignore unknown fields (enabling automatic MINOR version compatibility). MAJOR version changes require published migration guides and conversion tools.",
    "version_format": "MAJOR.MINOR",
    "folder_format": "v{MAJOR}.{MINOR}",
    "compatibility": "A parser conformant to vX.Y is compatible with all vX.Z files where Z >= Y, provided unknown fields are ignored per spec \u00a72.3."
  },
  "mime_types": {
    ".chron": "application/vnd.openchronology+json",
    ".chroncal": "application/vnd.openchronology.calendar+json",
    ".chronverse": "application/vnd.openchronology.universe+json",
    ".chronpkg": "application/vnd.openchronology.package+zip",
    ".chronstream": "application/vnd.openchronology.stream+ndjson"
  }
}