Roadmap
In place
The core behaviour set (press, including latching, pulse, hinge, dial, slide, grab in poseOnly and native modes, tossScore); gaze, both required gating and dwell-to-press; targeting, with provider hints beating the core's own hit-testing; capability negotiation with a visible behaviourDisabled outcome; events as the only outbound pathway; feedback intents with the two opt-in routing helpers; per-source velocity tracking; presence control on three.js, Babylon and IWSDK; the standalone three.js adapter, including a desktop mouse fallback and optional three-mesh-bvh acceleration; the Meta IWSDK adapter's one-call registerInteractions and native grab fulfilment; and the interaction playground demo.
Experimental or not yet run
The Babylon adapter is written against the documented Babylon 7 API and covered by structural fakes only; it has not yet been exercised against a real Babylon runtime. The Google XR Blocks adapter is marked experimental: the upstream API may still move. It is structurally typed against xrblocks v0.20.0, and has no haptics and no presence control, because the upstream package offers neither.
Deliberately not planned
Physics and ballistics stay with the app. A grab behaviour only ever reports a poseOnly carry or mirrors an engine's own native transitions; a throw's flight afterwards is the app's own code, demonstrated in the playground's own ballistics. Portable scene and content building beyond the shared InteractionDescriptor is not a current promise. Scene meshes, prefabs and placement remain the app's job, and a broader shared content descriptor is only under consideration once a second host actually needs one.
Also worth knowing
InteractionRuntime.onSourcesSampled is deprecated in favour of onSample; the two deliver an identical stream since Input 0.1.1 added velocity fields to every snapshot. It still works and will only be removed in a later major release.