open-standards/wai/CONTRIBUTING.md

Contributing to WAI

WAI is a specification (SPEC.md and its extensions/) with a reference implementation in Rust (wai-rs/, with wai-quantum/ and the browser crate wai-web/). Both are pre-1.0 drafts: substantive changes are welcome.

The canonical repository is the forge at https://git.transaction.science/Transaction-Science/open-standards. Send changes there; mirrors of it are read-only.

To the specification

A change is in scope if it:

• names a real ambiguity in the text (point at the section and the case that breaks);
• adds a missing structural requirement (byte layout, conformance rule, dispatch behaviour) needed to make another implementation falsifiable;
• registers a capability with a byte-precise payload format and conformance vectors, not a placeholder (see Registering a capability, below).

A change is out of scope if it adds optional fields with no testable conformance effect. §8 says what a revision may change: a registered capability's payload format and role are fixed once registered, and a later edition of a standard that changes its bitstream takes a new capability string.

Registering a capability

REGISTRY.md states the procedure: add the string to the registry table in wai-rs/src/codecs/, register it in SPEC §5 under the same heading, run wai registry export, and link it from the codec glossary or list it there as having no entry. The tests hold SPEC, the registry and the exported files to the same set of strings.

To the reference implementation

Building

The default codecs feature links system codec libraries (libjxl, libavif, libopus, libdav1d, liblzma, libflac); without them the build stops in a codec crate's build script. Everything else builds without them, and CI builds that way:

cd wai-rs
cargo test --lib --no-default-features --features world,audio_scene,haptic,splat4d,score,provenance,neural_int,film
cargo run --no-default-features --bin wai -- capabilities

Name the features a change touches explicitly; cargo test with the defaults is not what CI runs.

Tests that CI must see

• A test file gated on a feature (#![cfg(feature = "...")]) compiles to an empty binary, which reports success, in any build without that feature. Declare it in wai-rs/Cargo.toml with a [[test]] stanza and required-features, and add --test <name> with the right --features to a step in .github/workflows/, or to a verifier step's own file (below), or tag the file for the fast integer kernels' steps (below). A test no workflow names runs nowhere.
• A test that reads inputs from outside the tree skips without them. CI sets WAI_REQUIRE_SOTA_VECTORS=1 where it provides them, and a missing input then fails.
• Falsify every new test once: change the code it guards, show it fails, restore the code through git, and show it passes again.

Vectors

Committed conformance vectors and pinned hashes change only through their generator (the wai_*_vectors gen binaries and the export tools in tools/), never by hand. A test whose comment says its hex must never be edited to make it pass means exactly that.

Corpus content: where it comes from

Corpus content is generated in this repository, by a generator from a seed or a formula, or it is an input whose source and licence are recorded and whose licence permits redistribution. An image, a recording or footage that was not made here and has no such licence is not committed, as content or as training data.

Every corpus states its provenance: each *-conformance/README.md in a line that begins **Provenance.**, and wai-rs/tests/vectors/README.md in a row for each vector directory. The line names the generator and its input, and for an input not generated here, its source and licence. A word such as "synthetic" is not a provenance line. wai-rs/tests/corpus_provenance.rs requires the line in every corpus, and tools/wai_audio_provenance_check.py, which CI runs, fails when a committed audio vector correlates with a reference recording the host has.

A corpus can also keep a licence record for each vector, in a licences.json beside its README: the vector's licence, as an SPDX identifier from a list of licences that permit redistribution; whether its content is generated here or a third-party input; the generator and its input, or the source; and, for a vector whose model was trained, the same of its training data. neural-conformance keeps one. scripts/check-wai-corpus-licences.py, run on every change, fails on a vector of such a corpus that has no record, and on a record whose licence is outside that list or that leaves out what its content needs.

Independent implementations

Conformance is defined by the committed corpora (*-conformance/) and the criteria of SPEC §7, not by agreement with this implementation's own tests. A second implementation in another language is validated against the same corpora; the OER receipt kernel in C (oer-conformance/settle/) is one.

Changes that add files rather than append to shared lines

Many changes are open here at once, and a line two of them edit is a conflict that holds one of them back. So a change adds files of its own where the tree lets it (its changelog entry, and its lists in the conformance workflow), and in a file that stays shared it inserts beside the entry it builds on:

• Its changelog entry is a new file, changes/<yyyy-mm-dd>-<slug>.md, holding the entry as the changelog does (changes/README.md). It does not edit the head of CHANGELOG.md. The repository checks require a change under wai/ to add or edit an entry file directly in changes/ (a release, which renders the files and removes them, passes), or to carry the trailer line Changelog: none, exactly, in the trailer block of one of its commit messages. A pull request opened before the check reached main passes as it is; one opened since that adds its entry to the head of CHANGELOG.md fails.
• A step of the independent verifiers in wai-conformance.yml is a new file, .github/wai-conformance/verifiers/<name>.sh: the step's shell body, run in wai/, under a header of # key: value lines. # step: names it and # order: places it; # features: brings its features into WAI_FEATURES and its lists into the features-alone job; # paths: brings the extension text it reads into the paths the workflow's gate runs on (the trigger takes all of extensions/; a path under none of the trigger's paths still needs a line there, which check names); # bins: and # release-features: cover the rest, and every --test it runs with "$WAI_FEATURES" joins the job's first build. scripts/wai-conformance-lists.py states every key; python3 scripts/wai-conformance-lists.py dry-run prints every list and step the workflow runs, and run --only <name> runs one step.
• A cargo-class corpus is a new file of .github/wai-conformance/corpora/, naming its tool and directory. A test of the fast integer kernels carries the first line // wai-conformance: int-kernels (with int-kernels-amd when the AVX-512 host runs it too, or int-kernels-release alone when only the release step does), and the steps take its required features from Cargo.toml.
• A file every change still shares takes a new entry beside the entry it builds on, never at the end, and is not re-sorted. wai-rs/Cargo.toml's [features], [[bin]] and [[test]] tables, wai-rs/src/lib.rs's mod lines and the tables of wai-rs/src/codecs/registry.rs are grouped by topic, not sorted: a feature goes after the feature it depends on, a target after its sibling's, a module after the module it extends. registry/capabilities.json, the registry table of REGISTRY.md and vocab/v2.* are generated from registry.rs in sorted order, so a new row lands at its sorted place: never edit them by hand, and on a conflict in one take either side and run wai registry export again.
• .gitattributes. A corpus whose bytes must never be converted gives its own directory a .gitattributes (* -text), as pin-conformance/ and live-conformance/scene/ do (a verifier that lists its directory's files must admit that one, as scene_verify.py does), and adds no line to wai/.gitattributes. A pattern only that file can hold goes beside the line it is most like, with its comment, never at the end.
• The corpus table of live-conformance/README.md, and the list of verifier commands under it, take a new row beside the row of the extension it builds on or extends (a delivery record beside its delivery sibling, a live extension beside its live sibling), never at the end. The table is written by hand: its rows name sections, schemes and generators that no file of the corpora states.

Public text

The specification, the extensions, READMEs, research notes, code comments and the CHANGELOG state what WAI does, plainly:

• name no company, vendor, customer or commercial product. Standards, standards bodies, protocols, papers and open-source projects may be named, factually;
• make no comparisons with other products or approaches;
• give no counts that drift (crate counts, test counts, line counts).

Three checks enforce this. scripts/check-no-vanity-metrics.sh (opt-out marker allow-vanity: <reason>) and scripts/check-comparative-prose.sh (opt-out allow-phrase: <reason>, for an identifier or a quotation) run on every change. scripts/check-public-names.sh holds the names of the maintainers' products that their public site names in the script itself, since they are public already, and checks them on every change (--maintainer-products-only). Its other patterns are a private list (the WAI_NAME_DENYLIST secret in CI, given only to the run on a push to main, so a pull request is checked against that list when it lands). A functional identifier — a capability string, a model-hub id a tool defaults to, a repository URL, an OS API name, a security advisory id — is kept and its line marked allow-name: <reason>. Put the marker in a comment of the file's own syntax (<!-- ... -->, // ..., # ...); the reason must contain a letter or a digit. JSON has no comments, so a JSON file carries no such identifier: the codec glossary titles a format by its own name, FourCC, file extension or designation, and never by a company, a product or a person (glossary/SCHEMA.md). The checks fail closed: a pattern that does not compile, or any grep error, fails them, and scripts/test-public-text-checks.sh proves that on every run.

Dated research records are not rewritten: a correction is a dated annotation after the original text, and a name is redacted in place with a dated marker.

Licence

The specification and the reference implementation are Apache-2.0. By contributing, you agree your contribution is licensed under the same terms. Each payload and companion capability carries a licence class (royalty-free, patent-pool, proprietary, non-commercial) for implementing it, recorded in the registry; derivations carry the class codecs::derivation gives them; records carry none. Companion implementations outside this tree keep their own licences.

No CLA. The licence is the agreement.