Adds the "carries whatever it can reconstruct, verifies whatever it
carries" surface on top of the existing neural/codec WAI. All builds
green against this base (wai-rs all-features tests + clippy, wai-web
wasm, wai-spz-gen, wai-relay).
Reconstruct half — each a spec + conformance corpus + in-tab browser
sink that re-derives the corpus hash, over one wai.det.fixed64 floor:
- interactive worlds replay-equivalence (3 sim registrants,
relay multiplayer, session receipts, glTF + real-SPZ assets)
- spatial audio mixdown-equivalence
- haptics sample-equivalence
- state-feeds replay-equivalence (non-physics sim)
- avatars / digital humans pose-equivalence (+ telepresence)
- volumetric / 4D splats frame-state-equivalence (WebGPU EWA render)
Verify half (lever 4):
- asset provenance — signed, energy-accounted lineage for opaque
captured content WAI does not reconstruct; tamper-evident in-tab.
Cross-cutting: per-class JWP receipt profiles; a native energy meter
(IOReport via macmon, no sudo) emitting receipts with real measured
joules. Codecs gated behind a `codecs` feature (default on) so the
world/wasm sinks build without the C codec chain.
Excludes the separately-evolving neural subsystem (semantic path, GLC
rANS, ONNX tooling) to avoid reverting newer origin work.
Co-Authored-By: Claude Opus 4.8 <[email protected]>
3.6 KiB
WAI Extension: Haptics (DRAFT)
Status: PROMOTED 2026-06-13 — canonical copy at
extensions/haptics.md(site mirror). Edit the canonical copy. Reference impl:wai-rshaptic; corpus:haptic-conformance/; live sink: wai.transaction.science/haptics.
Keywords MUST, MUST NOT, SHOULD, MAY are RFC 2119/8174.
1. Scope and model
A wai.haptic.signal object is a per-channel keyframed envelope of
intensity and sharpness (the Core-Haptics-shaped pair every
modern actuator API maps to) that the sink reconstructs to a per-sample
buffer and plays on whatever actuators it has. It is lever 3
(instructions-at-the-sink) for touch — an effect is a few hundred bytes,
not a recorded waveform.
In scope: the container, the deterministic reconstruct contract, the sample-equivalence conformance criterion, the fallback floor, the receipt profile.
Out of scope: a transport; actuator hardware specifics (the channel→actuator binding is the sink's); carrier synthesis (the signal is an amplitude/sharpness envelope, not a modulated waveform — the deterministic floor stays trig-free).
Relationship to the core spec: mirrors interactive-worlds / spatial
audio. The reconstruct runs in the wai.det.fixed64 floor; media
takes the informational value "haptic"; wai.haptic.signal is
authoritative.
2. Container (WHAP)
"WHAP" | u16 n_sections | section table (u8 kind, u32 off, u32 len) | sections
| kind | section | required |
|---|---|---|
0x01 |
contract (canonical JSON) | REQUIRED |
0x02 |
channel signals | REQUIRED |
2.1 Contract
{ "sample_rate": 1000, "numeric": "wai.det.fixed64",
"channels": 1, "duration": 1500 }
Haptic rates are low (≈1 kHz); duration is in samples.
2.2 Channel signals
n_channels u32, then per channel: n_keys u16, then
n × ( pos_sample u64 | intensity i64 Fx | sharpness i64 Fx ).
Both fields are in [0, 1]. Between keyframes they linear-interpolate
in Fx; before the first / after the last key they hold.
3. Reconstruct contract
For each channel, for each sample t ∈ [0, duration):
intensity(t), sharpness(t) = the Fx linear interpolation of the
channel's keyframes at t, each clamped to [0,1] and quantized to a
u8 (round(v · 255), half away from zero, in integer space). The
canonical reconstruction is, per channel, the interleaved
[intensity, sharpness] u8 pairs.
4. Conformance — sample-equivalence
Given the same
wai.haptic.signal, a conforming sink MUST reconstruct the identical canonicalu8buffer, hence the identical BLAKE3 — on every machine, no tolerance parameter.
signal_hash = BLAKE3("wai:haptic-signal\x01" || per-channel u8 pairs)
5. Fallback floor
A sink with no actuators ignores the signal (haptics are
supplementary); there is no perceptual substitute to fall back to, so
fallback is typically null. A sink MAY surface the envelope visually
(a waveform) — presentation, not conformance.
6. Receipt (JWP profile)
signal_hash is the identity; the group's objects are per-channel
reconstruction blocks, Merkle-bound; one Ed25519 signature over
signal_hash + root + work (= duration × channels) + carried
joules_micro; parent_receipt_hash chains — the worlds/audio receipt
shape reused.
Appendix
Sample-equivalence is replay/mixdown-equivalence with the tick replaced
by the haptic sample. The envelope is trig-free by construction
(amplitude + sharpness, not a modulated carrier), so the Fx floor
reconstructs it exactly with +,−,×,÷ alone — the simplest cargo class
to make bit-exact, which is why it's the fast Phase-2 win.