CDIF Core

Core interoperability specification for CDIF (Cross-Domain Interoperability Framework). The CDIF Core profile defines the mandatory and optional base properties for any CDIF metadata record, implemented using the schema.org vocabulary.

Specification

• CDIFCoreImplementationGuide.md — Complete documentation of all classes and properties for the CDIF Core profile, including required/optional properties, data types, and JSON-LD implementation guidance.
• cdifCoreStructuredSchema.json — JSON Schema (Draft 2020-12) for validating CDIF Core profile instances. Generated from the metadataBuildingBlocks source schemas.
• coreRules.shacl — SHACL validation shapes for CDIF Core. Copied from metadataBuildingBlocks/_sources/cdifProperties/cdifCore/rules.shacl and should be updated whenever the source changes.

Required properties

Every valid CDIF Core instance must include:

• @id — Resource identifier (IRI)
• @type — Must include schema:Dataset
• @context — JSON-LD context with schema, dcterms, dcat, prov prefixes
• schema:name — Descriptive name
• schema:identifier — Primary identifier (string or PropertyValue)
• schema:dateModified — Last update date (ISO 8601)
• schema:license OR schema:conditionsOfAccess — Rights/access information
• schema:url OR schema:distribution — Access to the resource
• schema:subjectOf — CatalogRecord with dcterms:conformsTo including https://w3id.org/cdif/core/1.1

Examples

The examples/ directory contains 40+ validated JSON-LD dataset examples that conform to the CDIF Core profile. These are records that do NOT use Discovery-level properties (spatialCoverage, temporalCoverage, variableMeasured) — records with those properties are in the Discovery repository.

Sources include:

Source	Count	Description
CDIF/ESIP/ODIS	9	Minimal, simple, and template examples
ADA	10	Core-stripped records from ADA test corpus
Kaggle	10	Iris, Netflix, Titanic, etc. — harvested from landing page JSON-LD
Dataverse	7	Harvard, Borealis, DANS, JHU — via Dataverse schema.org export API
PSDI DCAT	5	CSD, ChASe, AFLOW, etc. — converted from DCAT via DCAT/dcat_to_cdif.py
FEDEO	1	Satellite data collection with WebAPI distribution (OpenSearch)

All examples pass cdifCore JSON Schema validation.

JSON-LD Framing and Validation

FrameAndValidate.py frames a JSON-LD document against the CDIF Core schema and optionally validates it:

# Frame and validate
python FrameAndValidate.py examples/exampleCdifCoreMinimal.json --validate

# Frame and save output
python FrameAndValidate.py examples/exampleCdifCoreMinimal.json -o framed.json

# Use a different schema
python FrameAndValidate.py input.jsonld --validate --schema my-schema.json

The script uses cdifCore-frame.jsonld to frame JSON-LD documents into the expected property structure. Context prefixes from the input document are automatically merged into the frame, so domain-specific prefixes (e.g. ada:, xas:) work without being pre-declared in the frame.

Requirements: pyld, jsonschema (pip install pyld jsonschema)

SHACL Validation

coreRules.shacl contains SHACL shapes for validating CDIF Core instances. This file is copied from metadataBuildingBlocks/_sources/cdifProperties/cdifCore/rules.shacl and should be updated whenever the source changes.

Repository structure

├── CDIFCoreImplementationGuide.md  Classes and properties documentation
├── cdifCoreStructuredSchema.json    JSON Schema for validation
├── cdifCore-frame.jsonld           JSON-LD frame for document framing
├── FrameAndValidate.py             JSON-LD framing and JSON Schema validation
├── coreRules.shacl                 SHACL validation shapes (synced from metadataBuildingBlocks)
├── examples/                       40+ validated Core-only JSON-LD examples
├── ODIS/                           Archived ODIS type-specific templates and examples
└── LICENSE

Relationship to other CDIF repositories

• Discovery — Extends Core with spatialCoverage, temporalCoverage, variableMeasured, measurementTechnique, quality
• metadataBuildingBlocks — Source building block schemas, SHACL rules, and profile definitions
• validation — Framing, batch validation, conformance checking, harvesting, and DCAT conversion tools

Changelog — v1.1.0

Released 2026-09-10 as v1.1.0. Content synced from the CDIF metadataBuildingBlocks source; see the release for the tagged snapshot and git log v1.1.0 for the per-commit history:

• Populated from metadataBuildingBlocks — *StructuredSchema.json, merged SHACL, JSON-LD frame, examples, and the normative FrameAndValidate.py generated from the building-block source; Examples/ renamed to examples/.
• CDIF v1.1 — profile conformance URIs migrated /1.0 → /1.1.
• License standardized on CC-BY-4.0.
• @id-reference tightening — bare {@id} reference slots sealed (additionalProperties: false + required: ['@id']); a canonical objectReference building block introduced as the strict node reference.
• prov:used wrapper reconciliation — the base generatedBy.prov:used accepts role-keyed wrappers (schema:instrument / bios:computationalTool / prov:reagent) alongside string / {@id} / inline prov:Entity; profiles pin a wrapper's shape via a constraint-only if/then (never a narrowed anyOf).
• skos:notation → single string at concept level (consistent with the codelist single-notation design).
• FrameAndValidate.py (normative, drift-checked against Cross-Domain-Interoperability-Framework/validation) — two-frame root-@type selection, context-aware schema:about, --conformance detection, cdif:-@id re-expansion, and (2026-08) reference-collapse on all document types + blank-node dedupe + agent schema:identifier unwrap, so @embed:@always-framed documents validate against the tightened schemas.
• Examples conformed to the tightened schemas throughout (PrimaryKey → cdi:ComponentPosition, reference slots → {@id}, CVE hasIntendedDataType → string, skos:notation → string, schema:additionalType URI → {@id}).

Branches

main is the current release — GitHub Pages serves it, so the published URLs always show the newest release. It is protected: changes reach it only by pull request, which means the merge is the release.

New work goes on the updates branch and is merged to main when a release is cut, then tagged v1.1.n. The former reviewRevision202606 branch is retained as archive202609.

License

See LICENSE.