open-standards/wai/changes/2026-11-09-conditioned-refinement.md

A refinement conditioned on side information both ends hold: wai.image.int_cond_refine

• One capability registered (SPEC §5, Refinement capabilities): wai.image.int_cond_refine, refinement-only, StandardDefined, with the staged form conditioned residual and the payload WCP1. Its row of Base admission is wai.image.int_refine's. A layer's next stage is three integer steps over the unit's current output and the side planes its refines.side names: the base prediction (the current output, or its up2_predict at the output's size), an integer network carried in the payload that reads the base prediction and the side planes and adds a correction clamped to [0, 255], and a WIR1 residual decoded over that prediction with the identity predictor. Every sink that holds the same side planes computes the same bytes, so the output is as exact as the base and the planes. The base, each side object and the layer are objects of their own, each named by its content hash and covered by its own receipt; the sink composes them and computes the stage, whose stage hash is the digest a signed stage claim states and a presenting sink checks.
• One mechanism, two uses. Over rendered content the side planes are G-buffers both sides hold (depth, normals, albedo), each carried as an exact object of its own, or the frame the sink renders itself from a wai.splat.int_codec object at a pinned pose with wai-splat-render:i1, which costs nothing on the wire. With no side plane, over a base at a lower resolution, the layer is the detail stream of a dual stream: the up2 of the low-resolution reference, and the detail the network reconstructs from it.
• Side planes (staged-delivery §3.1): refines.side, read for the conditioned form and ignored for any other, is absent, null, or 1 to 4 entries, each a content hash or {"object", "renderer": "wai-splat-render:i1", "pose"} with a pose of splat-exact §2; any other value is refines-malformed. A plane is exact when its object was decoded through its manifest's capability, not a fallback, at decode-equivalence. §4.1 step 4 checks each entry in order after base admission: the sink holds its plane (side-absent), and the plane is exact (side-not-exact). The two reasons join §4.2's closed list and the reasons a stage claim names (jwp-receipts §2.4.10). A plane is the sink's, held beside its chains and no part of a chain's state.
• The payload (staged-delivery §6.3, Appendix B): WCP1, a 12-byte header (predictor, n_side, n_layers, act_hi), the network in the layer form of exact-upscale §3.1 (the first layer reads 3·(1 + n_side) channels, the last writes 3), and a WIR1 residual of the RGB8 unit kind with the identity predictor. Its checks run in a stated order with Appendix A.6's codes; n_side must be the count side names. Its declared cost adds the network's working bytes and its multiply-accumulates, which a sink may limit (cost-over-limit, multiply-accumulates).
• Through the integer operator set. The network is one WHG1 graph, lowered by wcp1/1 (integer-operators §11, Appendix B.6 of staged-delivery): concat, rescale, conv, clamp and add, loaded under acc64 with its bounds certificate, which every payload that parses meets. The capability's ops member names the set, acc64, wcp1/1 and E1's modes.
• Carriage. A layer that reads side planes travels as a WAI1 object: a WAI2 refinement component carries no side (SPEC §7.1, refinement-side), and a packer refuses a WAI1 layer that carries one. One with no side plane packs and explodes as any layer.
• Reference implementation. wai-rs: staged::wcp1 (the parse, the cost, the lowering, the decode through the graph, the arithmetic loop by loop, which the encoder holds the graph to, and the encoder), staged::side (SideEntry, SidePose, read, with_side), staged::{is_conditioned, layer_units}, StageSink::{add_side, add_render, set_macs_limit}, StageChain::set_macs_limit, codecs::CAP_IMAGE_INT_COND_REFINE with AppliedForm::Conditioned, the WCP1 framing check, RoleError::RefinementSide; the session claim reads a conditioned layer's units from its WCP1 payload.
• Conformance. staged-conformance/cond/, written and checked by wai_staged_vectors (which now builds with splat_exact): exact side planes; the dual stream; both together, an 8 × 8 render with three 16 × 16 G-buffers; a rendered plane; a plane not held, then held; planes that are not exact (an unpinned decode, a fallback, the render of an unpinned splat set); a plane of another size; a base the row does not admit; side broken each way; each WCP1 check broken once; cost limits on working bytes and on multiply-accumulates; and cond/wai2/. staged_verify.py replays every case with its own WCP1 parser, its own network loop and its own sink, decodes each side object's PNG, and renders each plane with live-conformance/splat_exact_verify.py's renderer.
• Breaking: staged::StageRefusal gains SideAbsent and SideNotExact, so StageRefusal::ALL holds 16 reasons where it held 14, and codecs::AppliedForm gains Conditioned: api:rust:wai::staged::StageRefusal::ALL, api:rust:wai::codecs::AppliedForm::Conditioned. A caller that matches AppliedForm exhaustively adds an arm for the conditioned form; one that reads StageRefusal::ALL as an array of 14 reads its length.