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FAIR² Certification

!!! warning "Draft — pending governance" The two-tier certification model and the fair2s:CertificationShape SHACL shape in this document are drafts. Three governance questions (Decisions A, B, and C at the end of this page) are unresolved. Producers and consumers SHOULD NOT rely on the binding semantics of fair2:FAIR2-Certified or fair2:FAIR2-Validated until these decisions are finalised by the FAIR² governance body.

Overview

FAIR² defines two distinct statuses for a dataset package:

  • FAIR²-Validated — a quality status asserting that all automated conformance checks pass.
  • FAIR²-Certified — an authority assertion backed by a cryptographically signed credential from an authorised certifier.

The distinction is who vouches for the package, not the level of automation used during verification. A fully automated pipeline operated by an authorised certifier produces a valid FAIR²-Certified credential.

FAIR²-Validated

An assertion that the following automated checks all passed:

  • SHACL validation against the declared FAIR² compliance level — 0 errors, 0 warnings
  • All required metadata fields present and correctly typed
  • _meta.version and _meta.dateModified current
  • license URI resolves and is consistent with the declared accessRights
  • All distribution SHA-256 checksums declared (not necessarily verified against actual file downloads)

FAIR²-Validated can be asserted by any FAIR² validator authorised by the governance body (Clara, or any licensed toolchain). It is a status flag in the metadata, not a signed credential. It carries no legal or contractual standing.

FAIR²-Certified

An assertion backed by a cryptographically signed credential issued by an authorised certifier. In addition to everything required for FAIR²-Validated:

  • The credential is signed by a DID listed in the FAIR² authorised-certifier registry (see Authorised certifiers)
  • certificationScope is explicitly declared (see below)
  • certificationDocument points at an external fair2-cert.json file whose signature verifies
  • certifiedBy references an authorised Organization with a resolvable identifier

certificationScope

certificationScope is a required array of tokens on both the Certification pointer node (inside fair2.json) and the full credential (in fair2-cert.json). It declares exactly what was verified during certification, so consumers can make access decisions without fetching the external credential.

Canonical vocabulary

Token Meaning
metadata-conformance SHACL validation passed at the declared compliance level
data-integrity SHA-256 checksums verified against actual file downloads
license-verification License URI resolves; access rights consistent with declared level
process-attestation Provenance activity and software-agent records reviewed
temporal-proof RFC 3161 timestamp or blockchain anchor attached

Standard scope combinations

  • Full scope (recommended for Level 0 / open access): ["metadata-conformance", "data-integrity", "license-verification", "process-attestation"]
  • Metadata-only (restricted datasets where the certifier has no access to the files): ["metadata-conformance", "license-verification"]

The pointer node in fair2.json

A lightweight Certification node is embedded in the Dataset's graph so consumers can assess certification status without fetching the full credential:

{
  "@id": "certification/fair2-cert-2026",
  "@type": "Certification",
  "certifiedBy": {
    "@type": "Organization",
    "name": "Senscience",
    "identifier": "https://sen.science/"
  },
  "dateIssued": "2026-04-16",
  "fair2ComplianceLevel": "fair2:FAIR2-Certified",
  "certificationDocument": "https://sen.science/certifications/10.71728/r1rj-f947/fair2-cert.json",
  "verificationEndpoint": "https://sen.science/certifications/10.71728/r1rj-f947",
  "certificationScope": [
    "metadata-conformance",
    "data-integrity",
    "license-verification",
    "process-attestation"
  ]
}

Authorised certifiers

fair2:AuthorizedCertifier is a governance concept. An authorised certifier is any entity whose DID appears in the FAIR² certifier registry, maintained by the FAIR² governance body. Senscience is the primary authorised certifier; third parties may apply for certification authority under a trademark licence.

Governance rules

  • Conflict of interest. A funder of a dataset MUST NOT be the certifier of that same dataset. The funding[].funder list MUST NOT overlap with certifiedBy.
  • Scope limitation for restricted data. Certifiers without access to the data files MUST declare certificationScope as ["metadata-conformance", "license-verification"] only.
  • Non-commercial licence rule. Third-party certifiers operating under the non-commercial FAIR² trademark licence MUST NOT certify datasets hosted on commercial platforms without upgrading to a commercial licence.

Registry format

The registry is a JSON-LD document published at https://fair2.ai/certifiers/registry.json. Each entry carries the certifier's DID, organisation name, licence tier, allowed certification scope, and validity period.

Open governance decisions

The following design questions are unresolved. The certification semantics described above are provisional pending these decisions.

Decision A — Scope label for partial certification

Does metadata-only scope still carry the fair2:FAIR2-Certified compliance level, or should restricted-data packages receive a distinct label (e.g., fair2:FAIR2-Certified-Metadata)? Implications: discoverability, consumer trust, and whether partial certification is a first-class status or a downgrade.

Decision B — Self-assertability of FAIR²-Validated

Can a data producer run a conformant validator locally and embed fair2ComplianceLevel: "fair2:FAIR2-Validated" in their own metadata without involving an authorised validator? If yes, Validated is a declaration, not a credential — low trademark exposure but potential brand dilution. If no, even Validated requires an authorised issuer (a lighter-weight one), which adds friction but protects the brand.

Decision C — Expiry model

Are certifications permanent (revocation-only invalidation) or do they expire annually and require re-certification? Annual expiry strengthens trust but imposes ongoing operational burden on producers and certifiers.