H2KG Ontology

Developer Guide

EMMO-aligned ontology for hydrogen electrochemical systems, experiments, materials, measurements, and FAIR metadata

H2KG Ontology logoOntology release

Developed through DECODE, the Helmholtz Metadata Collaboration (HMC), and AIMWORKS to support FAIR ontology publication and reusable metadata infrastructure for hydrogen electrochemical systems.

ODK Operations

The nested ODK project lives under ontology_release/odk/. Its outputs are copied into ontology_release/output/odk/ and then rendered through the AIMWORKS docs site.

  • ontology_release/odk/src/ontology/run.bat make odkversion
  • ontology_release/odk/src/ontology/run.bat make test
  • ontology_release/odk/src/ontology/run.bat make refresh-imports
  • ontology_release/odk/src/ontology/run.bat make prepare_release
  • ontology_release/odk/src/ontology/run.bat make validate_profile_h2kg-edit.owl

Ownership Boundary

ODK handles edit-file lifecycle, imports, ROBOT-oriented QC, and standard machine releases. The Python release pipeline still owns schema/example separation, mappings, FAIR reporting, custom docs, profile modules, w3id assets, and the release bundle.

Architecture note: ODK is nested and intentionally not allowed to overwrite the AIMWORKS repo-root workflow structure.

Current ODK Status

Status: enabled

Last built: 2026-04-24T10:17:22+00:00

When to Use HDO vs EMMO vs PROV / DCTERMS

  • HDO first: data, metadata, identifier, digital object, information profile, schema, validation, and provenance-record concepts.
  • EMMO / ECHO first: scientific process, material, measurement, and electrochemistry semantics.
  • QUDT first: quantity kinds, quantity values, and units.
  • ChEBI first: chemical entities.
  • PROV-O / DCTERMS first: publication provenance and ontology release metadata.

Current HDO-aligned terms in this run: 5

Optional Local QC Hooks

Optional local checks are non-blocking and currently not required for release promotion.

  • OWL consistency hook: install owlready2 to enable it locally.
  • EMMO checks: install EMMOntoPy to enable them locally.
  • CI default: these hooks remain optional unless the project explicitly promotes them into required CI dependencies.