open-standards/wai/vocab

WAI vocabulary

Stable IRIs for the Web AI Media Transport & Execution open standard, in two versions. A WAI manifest that carries one of the JSON-LD contexts below expands into typed RDF triples for any JSON-LD or SPARQL consumer without changing its wire form. Licence Apache-2.0, matching the reference implementation.

v2 — generated from the registry

Namespace: https://wai.transaction.science/vocab/v2#.

File	Format	What
v2.ttl	Turtle (RDF)	One IRI per string SPEC §5 registers, with its kind, status, media class, role, fidelity tier, licence class, replicate class, registering section, edition and registration date (registeredOn); the enumerations as individuals named <class prefix>-<label> (kind-companion, role-companion, media-image, …), so no two terms share an IRI; and the manifest terms the context maps.
v2.jsonld	JSON-LD @context	For a WAI manifest, WAI1 or WAI2, as written on the wire: capability, fallback and a component's companion_of expand to capability IRIs, media to a media-class individual; kind and a component's role are plain strings under terms of their own (payloadKind, componentRole), and target is a JSON literal. prior (conditioning.prior, or a component's) maps its members to the pin terms below.
v2.shapes.ttl	SHACL Core	Applies to a manifest with or without an @type (it targets every node with a wai or intent field, and every component of renditions). Checks that a WAI1 names a capability and a WAI2 a component list, never both; the capability and every component's capability against the registered payload and companion capabilities that are not candidates; the fallback and a companion's base against the registered payload capabilities that are not candidates. media is informational and a reader accepts a value it does not know (SPEC §3, §8), so only its form is checked. The shapes check a manifest against this revision's registry: a violation for a capability or fallback this revision does not register means the string is not registered in this revision, not that the envelope fails to conform or cannot be dispatched, since a later MINOR revision may register it (SPEC §4, §8). Also checks every parameter-set pin, wherever the manifest carries one (below).

The three files are generated by wai registry export from the reference implementation's registry (wai-rs/src/codecs/registry.rs), together with ../registry/capabilities.json; a library test and a CI step fail when they drift. check_shapes.py expands sample manifests, typed and untyped, through the context and validates them against the shapes, each with the result it must give; CI runs it (.github/workflows/wai-conformance.yml). Do not edit the generated files by hand — ../REGISTRY.md says how a string is registered. The v2 IRIs resolve only once the website publishes the files.

v1 — stable

Namespace: https://wai.transaction.science/vocab/v1#. The v1 files (v1.jsonld, v1.ttl, v1.shapes.ttl) are stable in this sense: no v1 IRI is removed, and no term changes what it means, so nothing that already names them breaks. A label or comment may be corrected, and a term may be added. They cover the first codec menu only (PNG, JPEG, AVIF, JPEG XL, FLAC, Opus, AV1, zstd, XZ) and model the neural and zeroth paths as classes; they are not the registry. v1's SHACL shape rejects a manifest that names any other registered capability, so a validator of current manifests uses v2.

The parameter-set pin, in both versions

The parameter-set pin (wai:ParameterSetPin, SPEC §3.1) is in v1 as additive terms, and wai registry export writes the same terms into v2: wai:prior and the members wai:pinId, wai:pinSha256, wai:pinDeterminism, wai:pinForm, wai:pinTier (a closed vocabulary: decode-equivalence, entropy-consistency, none) and wai:pinSupersedes, with a scoped JSON-LD term prior whose members are the manifest's own names, a ParameterSetPinShape and a SupersedesShape. In v2 the tier list is generated from the registered tokens (codecs::TIER_TOKENS). wai:sharedPriorUri and wai:sharedPriorHash (v1 only) describe a located prior with a BLAKE3 hash; they are not the manifest's pin. A library test in wai-rs (container::tests::vocab_pin_terms_match_prior_members) reads both v1 and v2 and holds each scoped term's members equal to the pin's serialized members and each shape's tier list equal to the registered tokens; check_shapes.py validates conforming and non-conforming pins against the v2 shapes.