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ADR 0002 — EUDPP IRIs rebase to canonical https://w3id.org/eudpp/

Status: Accepted Date: 2026-05-08 Deciders: dppvalidator maintainers (drafted during CIRPASS-2 migration planning) Migration-plan label: D-0.3 Related phases: Phase 0 (verification), Phase 1 (rebase)

Context

The EUDPP namespace constants in src/dppvalidator/vocabularies/ontology.py bind EUDPP class IRIs to the publishing host of each module:

Python
class EUDPPNamespace(str, Enum):
    EUDPP = "http://dpp.taltech.ee/EUDPP#"  # TalTech publishes P_DPP / SOC / ACTOR / CON / CORE
    LCA = "http://dpp.cea.fr/EUDPP/LCA#"  # CEA France publishes LCA
    ...

These IRIs are accurate as origin URLs for the historic v1.7.1 / v2.0 TTL bytes — the bytes literally lived under those hosts.

The CIRPASS-2 v1.9.1 / v1.9.4.Maki release on the DPP Vocabulary Hub declares a different identifier basis. The CORE umbrella module's metadata (per https://dpp.vocabulary-hub.eu/specifications, 2026-05-08) states:

EUDPP CORE ontology maps the ontology modules by importing them. The imports are from https://w3id.org/eudpp.

https://w3id.org/eudpp is a permanent identifier (W3ID) that redirects to whichever publisher hosts the bytes today. As of v1.9.1, the canonical IRIs of the EUDPP modules are:

  • https://w3id.org/eudpp/ (CORE)
  • https://w3id.org/eudpp/p_dpp/
  • https://w3id.org/eudpp/soc/
  • https://w3id.org/eudpp/lca/
  • https://w3id.org/eudpp/actor/
  • https://w3id.org/eudpp/con/

Continuing to emit dpp.taltech.ee / dpp.cea.fr IRIs from EUDPPJsonLDExporter produces JSON-LD that downstream consumers cannot dereference: the predicates point at non-canonical hosts. Linked-data unification breaks.

Decision

All EUDPP namespace bindings rebase onto the canonical https://w3id.org/eudpp/ prefix in Phase 1.

Specifically:

  • EUDPPNamespace.EUDPP → "https://w3id.org/eudpp/".
  • EUDPPNamespace.LCA → "https://w3id.org/eudpp/lca/".
  • New per-module bindings added: P_DPP, SOC, ACTOR, CON.
  • All 170 rows of TERM_MAPPINGS rebase predicate IRIs.
  • The bundled eudpp-context-v1.9.1.jsonld carries the canonical IRIs.
  • The legacy CIRPASSNamespace = EUDPPNamespace alias at vocabularies/ontology.py:59 is deleted: it conflated messages (CIRPASS) with axioms (EUDPP). Phase 3 introduces a distinct CIRPASSMessageNamespace if needed for the message-tree shape.
  • Old IRIs remain registered in exporters/contexts.py for one release with a DeprecationWarning; removed in Phase 10.

A precondition gate runs in Phase 0: python tools/snapshot/fetch_cirpass.py --verify-canonical HEAD-pings each canonical IRI. Non-zero exit (R12 in the plan) blocks Phase 1 until the IRIs resolve, with two escalation paths:

  1. The IRIs are not yet wired up by W3ID; coordinate upstream and wait. Phase 1 is paused.
  2. The IRIs are intentionally different from what the spec page states; update this ADR with the corrected basis and re-run the gate.

Consequences

Positive

  • EUDPP-LD output is canonically dereferenceable.
  • MANIFEST.json rows can carry a meaningful canonical_iri field separately from the (mutable) host URL the bytes were vendored from.
  • Future re-publishings (TalTech → some new publisher; CEA → some new publisher) leave canonical IRIs unchanged.

Negative

  • This is a coordinated rewrite, not a version bump. Phase 1's scope is larger than "refresh the TTLs"; it includes the IRI rebase across 170 mapping rows, 5 enum modules, and the JSON-LD context.
  • Downstream consumers that pinned the old taltech.ee / cea.fr IRIs break. We mitigate with a one-release deprecation window (0.5.0 → 0.6.0) and call out the change in docs/concepts/eudpp-1.9-changelog.md.
  • W3ID is a redirector, not a host. If the redirector is briefly down, consumers that follow the IRI lose the dereferencing path. This is a reliability concern for downstream code, not for our emission.

Alternatives considered

  • Keep per-publisher IRIs. Rejected: non-canonical; the spec declares a different basis; LD consumers fail.
  • Dual-emit both IRI sets (legacy + canonical). Rejected: an LD document with two predicates for the same property is semantically ambiguous.
  • Defer the rebase to a later phase, ship v1.9.1 axioms with old IRIs first. Rejected: produces a broken-by-design intermediate release; users would update and immediately get non-canonical emissions.

Validation hooks

  • tools/snapshot/fetch_cirpass.py --verify-canonical — Phase 0 task 0.4.
  • tests/unit/test_namespace_canonicality.py (Phase 1) — every emitted EUDPP IRI starts with https://w3id.org/eudpp/; no taltech.ee / cea.fr references remain in the codebase.
  • tests/integration/test_eudpp_export_v1_9.py (Phase 1) — golden-diff audit of EUDPP-LD output for the canonical v0.7 fixture.

References