What is standardized
Fiscal402 defines a verifiable representation of a fiscal event. The public, stable object today is fiscal402.receipt / 1.0.0. Canonicalization, signatures and artifact hashes are part of that contract. Anyone with the receipt, JWKS and bound bytes can check integrity without calling Fiscal402.
Conceptual objects
The execution architecture uses additional types. They are not all public JSON APIs today.
| Object | Status |
|---|---|
| PaymentAdapter | Internal — protocol → PaymentEvidence |
| PaymentEvidence | Internal / north-star — normalized settlement input |
| FiscalEvent | Internal / north-star — payment + parties + supply |
| JurisdictionRouter | Internal — selects an engine |
| FiscalDetermination | OUTPUT of processing FiscalEvent; projected onto the receipt |
| FiscalArtifact | Bound by hash on the receipt |
| fiscal402.receipt/1.0.0 | CURRENT public spec, frozen |
| fiscal402.receipt/2.0.0 | EXPERIMENTAL generic spec |
Current public receipt spec
fiscal402.sorted-json/1— compact JSON, recursive alphabetic keys, UTF-8. Not RFC 8785 / JCS.- SHA-256 of that canonical UTF-8 string.
- Ed25519 over the hex digest string.
kidreceipt-ed25519-v1. - UBL hash: SHA-256 of exact generated UTF-8 bytes. Identifier
sha256-utf8-bytes.
One primitive, over time
One verifiable fiscal event format, independent of how value moved. Today the production path is x402 v2 exact, EU VAT, and fiscal402.receipt/1.0.0. Receipt v2 is experimental. UK VAT is an experimental determination path and does not emit a statutory invoice. Additional rails and engines are future architecture.