Epic: codec standards-adoption architecture (spec 087)

[ignromanov]

Spec: 087-codec-standards-adoption (voidpay-ai ops/specs/087-codec-standards-adoption/spec.md)
Author: kai-cto · Date: 2026-05-28

Goal

A layered, additive-only architecture for adopting external standards over time
without ever touching the LOCKED schema v1 wire format (Constitution IV).

L3 @void-layer/export  — renderers over decoded model (EN16931 / UBL / CII / Factur-X / schema.org)
L2 @void-layer/interop — Hybrid C: pure projections + asCaip() View + EIP derive/receipt
L1 @void-layer/codec   — LOCKED v1, APPEND-ONLY (new dict codes / new even-odd TLV types only)
   flow: wire bytes → decode → canonical raw model → projection / renderer

Plug-in contract: every new standard answers — which layer? input? output (lossy?)?
touches existing artifacts (must not)? Wire additions go through the append-only registry

• dict-lock hash test; interop/export additions are new modules behind a stable interface.

Ratified principle: CAIP / standard strings are API-boundary projections only — the
void-layer wire format never contains them.

Decision matrix → sub-issues

Verdict: 🟢 adopt now · 🟡 gated/scoped · 🔵 defer (mechanism ready) · ⚪ watch

Standard	Layer	Verdict	Pri	Issue
CAIP-2/10/19 projection	L2	🟢	P1	#9
schema.org/Invoice JSON-LD	L3	🟢	P1	#10
ISO 4217 fiat/token metadata	L1 new + L2	🟢	P1	#11
EN 16931 BT annotations (docs)	L3 docs	🟢	P2	#12
EIP-712 receipt + TLV type 33	L2 + L1 append	🟡	P2	#13
EIP-681 derive (opt-in)	L2	🟡	P2	#14
Factur-X (PDF/A-3)	L3	🟡 spike	P3	#15

Deferred / watch (no sub-issue yet — not actionable)

• EN 16931 → UBL/CII renderers (L3, P3) — v1.6 merchant track
• CAIP non-EVM dict codes (Solana solana: / Bitcoin bip122:) (L1 append, P4) — when chain added; mechanism ready
• Peppol BIS Billing 3.0 (L3 transport, P4) — ~2029 (ViDA 2030); needs certified Access Point
• DTI (ISO 24165) (watch) — gated on MiCA CASP-scope legal opinion

Open items (tracked, not blockers)

• Factur-X path decision (pdfium WASM vs pdf-lib low-level vs stateless edge step) — product call on zero-backend strictness
• MiCA CASP scope legal opinion (gates DTI)
• EIP-712 TLV type 33 raw-field set confirmation before allocation
• USDT 3-tier annotation (tether_native / usdt0 / bridge_wrapped) in token dict metadata