> ## Documentation Index
> Fetch the complete documentation index at: https://docs.algovoi.co.uk/llms.txt
> Use this file to discover all available pages before exploring further.

# x402 Document Index

> Neutral index of IETF Internet-Drafts, published specifications and URN registrations in the x402 receipt format ecosystem, by author and by anchor.

This page is a neutral index of documents in the x402 receipt-format ecosystem. It is maintained by AlgoVoi as the author of the canonicalisation substrate (`urn:x402:canonicalisation:jcs-rfc8785-v1`). Inclusion is informational; absence is not normative.

The index is organised three ways:

* **By IETF posting status** -- what's on the datatracker today.
* **By author / publisher** -- who wrote what.
* **By canonicalisation anchor** -- which documents share which canon pin.

Each entry links to the document's primary surface and notes the canonicalisation discipline it anchors to.

## Authoritative anchor

The canonicalisation discipline this ecosystem converges on is specified in:

* **IETF Internet-Draft**: [`draft-hopley-x402-canonicalisation-jcs-v1`](https://datatracker.ietf.org/doc/draft-hopley-x402-canonicalisation-jcs-v1/) (Independent Submission, Informational; AlgoVoi sole authorship)
* **URN**: `urn:x402:canonicalisation:jcs-rfc8785-v1`
* **Registration authority**: Section 10.1 of the I-D above

A document is considered part of the x402 receipt-format ecosystem if it pins this URN as its canonicalisation discipline. Documents that pin a different canonicalisation discipline are out of scope of this index.

## By IETF posting status

### POSTED on IETF datatracker

| Internet-Draft                                                                                                             | Author                             | Stream                                | Posted                                                                | Anchor URN cite                                                                                     |
| -------------------------------------------------------------------------------------------------------------------------- | ---------------------------------- | ------------------------------------- | --------------------------------------------------------------------- | --------------------------------------------------------------------------------------------------- |
| [`draft-hopley-x402-canonicalisation-jcs-v1`](https://datatracker.ietf.org/doc/draft-hopley-x402-canonicalisation-jcs-v1/) | Christopher Hopley (AlgoVoi, sole) | Independent Submission, Informational | 2026-05-24 (-00); 2026-05-25 (-01, -02); 2026-05-29 (**-04** current) | self (defines URN in §10.1)                                                                         |
| [`draft-hopley-x402-compliance-receipt`](https://datatracker.ietf.org/doc/draft-hopley-x402-compliance-receipt/)           | Christopher Hopley (AlgoVoi, sole) | Independent Submission, Informational | 2026-05-24 (-00); 2026-05-25 (-01, -02)                               | `urn:x402:canonicalisation:jcs-rfc8785-v1` (explicit)                                               |
| [`draft-hopley-x402-settlement-attestation`](https://datatracker.ietf.org/doc/draft-hopley-x402-settlement-attestation/)   | Christopher Hopley (AlgoVoi, sole) | Independent Submission, Informational | 2026-05-25 (-00 + -01)                                                | `urn:x402:canonicalisation:jcs-rfc8785-v1` (explicit)                                               |
| [`draft-hopley-x402-cancellation-receipt`](https://datatracker.ietf.org/doc/draft-hopley-x402-cancellation-receipt/)       | Christopher Hopley (AlgoVoi, sole) | Independent Submission, Informational | 2026-05-25 (-00 + -01)                                                | `urn:x402:canonicalisation:jcs-rfc8785-v1` (explicit)                                               |
| [`draft-hopley-x402-refund-receipt`](https://datatracker.ietf.org/doc/draft-hopley-x402-refund-receipt/)                   | Christopher Hopley (AlgoVoi, sole) | Independent Submission, Informational | 2026-05-24 (-00); 2026-05-25 (-01, -02)                               | `urn:x402:canonicalisation:jcs-rfc8785-v1` (explicit)                                               |
| [`draft-hopley-x402-composite-trust-query`](https://datatracker.ietf.org/doc/draft-hopley-x402-composite-trust-query/)     | Christopher Hopley (AlgoVoi, sole) | Independent Submission, Informational | 2026-05-25 (-00 + -01)                                                | `urn:x402:canonicalisation:jcs-rfc8785-v1` (explicit)                                               |
| [`draft-hopley-x402-payment-evidence-frame`](https://datatracker.ietf.org/doc/draft-hopley-x402-payment-evidence-frame/)   | Christopher Hopley (AlgoVoi, sole) | Independent Submission, Informational | 2026-05-30 (**-00** current)                                          | `urn:x402:canonicalisation:jcs-rfc8785-v1` (explicit)                                               |
| [`draft-vauban-x402-stark-receipts`](https://datatracker.ietf.org/doc/draft-vauban-x402-stark-receipts/)                   | Vauban Pay (seritalien)            | Independent Submission, Informational | 2026-05-21 (-00); 2026-05-23 (-01); 2026-05-25 (-02)                  | `urn:x402:canonicalisation:jcs-rfc8785-v1` (explicit, 5 in-document hits)                           |
| [`draft-vauban-x402-lifecycle-fsm`](https://datatracker.ietf.org/doc/draft-vauban-x402-lifecycle-fsm/)                     | Vauban Pay                         | Independent Submission, Informational | 2026-05-25 (-00 + -01)                                                | RFC 8785 only (no URN citation; references "JCS canonical preimage discipline" terminology)         |
| [`draft-vauban-x402-vpsf-algebra`](https://datatracker.ietf.org/doc/draft-vauban-x402-vpsf-algebra/)                       | Vauban Pay                         | Independent Submission, Informational | 2026-05-25 (-00 + -01)                                                | RFC 8785 only (no URN citation; references "JCS canonical preimage discipline" terminology)         |
| [`draft-vauban-x402-starknet-anchor`](https://datatracker.ietf.org/doc/draft-vauban-x402-starknet-anchor/)                 | Vauban Pay                         | Independent Submission, Informational | 2026-05-25 (-00 + -01)                                                | RFC 8785 only (no URN citation)                                                                     |
| [`draft-vauban-x402-delegation-binding`](https://datatracker.ietf.org/doc/draft-vauban-x402-delegation-binding/)           | Vauban Pay                         | Independent Submission, Informational | 2026-05-25 (-00 + -01)                                                | RFC 8785 only (no URN citation; references "JCS canonical preimage discipline" terminology)         |
| [`draft-vauban-x402-pqc-receipts`](https://datatracker.ietf.org/doc/draft-vauban-x402-pqc-receipts/)                       | Vauban Pay                         | Independent Submission, Informational | 2026-05-25 (-00 + -01)                                                | RFC 8785 only (no URN citation; references "JCS canonical preimage discipline" terminology)         |
| [`draft-sato-soos-mjwt`](https://datatracker.ietf.org/doc/draft-sato-soos-mjwt/)                                           | Sato / Soos                        | Independent Submission, Informational | 2026-05-25 (-00)                                                      | Out of scope (Mandate JWT for agentic-AI authorisation; broader than x402 receipt-format substrate) |

**14 IETF Internet-Drafts in x402 namespace as of 2026-05-30.**

* **AlgoVoi-authored**: 7 (canonicalisation discipline + 6 receipt/frame formats: compliance, settlement, cancellation, refund, composite-trust-query, payment-evidence-frame)
* **Vauban-authored**: 6 (STARK receipts + lifecycle FSM + claim algebra + Starknet anchor + delegation binding + PQC discipline)
* **Sato/Soos-authored**: 1 (MJWT, broader agentic-AI authorisation scope)

### Canonicalisation anchor coverage

Of the 13 in-scope x402 receipt-format I-Ds (excluding `draft-sato-soos-mjwt`):

* **8 of 13** cite `urn:x402:canonicalisation:jcs-rfc8785-v1` explicitly (all 7 AlgoVoi I-Ds + `draft-vauban-x402-stark-receipts`)
* **5 of 13** reference "JCS canonical preimage discipline" terminology and RFC 8785 directly, without citing the URN registration registered in §10.1 of `draft-hopley-x402-canonicalisation-jcs-v1` (all the post-2026-05-25 Vauban revisions: lifecycle-fsm, vpsf-algebra, starknet-anchor, delegation-binding, pqc-receipts)

The 5 non-URN-citing Vauban I-Ds use the canonicalisation discipline as published by this document index, including the schema-normalisation rules (integer-millisecond timestamps, ordered arrays as significant, in-band `canon_version` pin) that extend beyond RFC 8785 alone. A normative reference to `draft-hopley-x402-canonicalisation-jcs-v1` or the `urn:x402:canonicalisation:jcs-rfc8785-v1` URN in next revisions of those I-Ds would make the anchor citation unambiguous; this is observed as an anchor-citation gap at the time of revision below, not as a substrate fork.

The substrate is uni-anchor in implementation (both AlgoVoi and Vauban encode JCS RFC 8785 with the same schema-normalisation rules) and uni-anchor in URN-registration authority (only `urn:x402:canonicalisation:jcs-rfc8785-v1` is defined in this namespace). The gap is at the citation layer only.

### Published specifications (not yet at IETF)

| Spec                       | Author / Publisher                        | Surface                                                                                                                                                                                                                                         | Anchor URN                                 |
| -------------------------- | ----------------------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ------------------------------------------ |
| `urn:crest:trust-check-v1` | Crest Deployment Systems LLC (Andy Salvo) | [`verify.crestsystems.ai`](https://verify.crestsystems.ai) + [`supership.crestsystems.ai`](https://supership.crestsystems.ai) -- general-service-trust envelope, hosted endpoint, JCS + Ed25519, content-addressed `query_ref` / `response_ref` | `urn:x402:canonicalisation:jcs-rfc8785-v1` |

## By author / publisher

### AlgoVoi (substrate author)

| Surface                                                                                                                                                                                                             | Type                                                                                                                          | Anchor           |
| ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ----------------------------------------------------------------------------------------------------------------------------- | ---------------- |
| [`draft-hopley-x402-canonicalisation-jcs-v1`](https://datatracker.ietf.org/doc/draft-hopley-x402-canonicalisation-jcs-v1/)                                                                                          | IETF I-D, Independent Submission                                                                                              | self             |
| [`draft-hopley-x402-compliance-receipt`](https://datatracker.ietf.org/doc/draft-hopley-x402-compliance-receipt/)                                                                                                    | IETF I-D, Independent Submission                                                                                              | `jcs-rfc8785-v1` |
| [`draft-hopley-x402-settlement-attestation`](https://datatracker.ietf.org/doc/draft-hopley-x402-settlement-attestation/)                                                                                            | IETF I-D, Independent Submission                                                                                              | `jcs-rfc8785-v1` |
| [`draft-hopley-x402-cancellation-receipt`](https://datatracker.ietf.org/doc/draft-hopley-x402-cancellation-receipt/)                                                                                                | IETF I-D, Independent Submission                                                                                              | `jcs-rfc8785-v1` |
| [`draft-hopley-x402-refund-receipt`](https://datatracker.ietf.org/doc/draft-hopley-x402-refund-receipt/)                                                                                                            | IETF I-D, Independent Submission                                                                                              | `jcs-rfc8785-v1` |
| [`draft-hopley-x402-composite-trust-query`](https://datatracker.ietf.org/doc/draft-hopley-x402-composite-trust-query/)                                                                                              | IETF I-D, Independent Submission                                                                                              | `jcs-rfc8785-v1` |
| [`draft-hopley-x402-payment-evidence-frame`](https://datatracker.ietf.org/doc/draft-hopley-x402-payment-evidence-frame/)                                                                                            | IETF I-D, Independent Submission (-00, 2026-05-30)                                                                            | `jcs-rfc8785-v1` |
| [`algovoi-substrate`](https://pypi.org/project/algovoi-substrate/) (PyPI) + [`@algovoi/substrate`](https://www.npmjs.com/package/@algovoi/substrate) (npm)                                                          | Reference implementation (Apache 2.0)                                                                                         | `jcs-rfc8785-v1` |
| [`algovoi-compliance-receipt`](https://pypi.org/project/algovoi-substrate/) and five other format-specific packages on PyPI + npm (refund, settlement, cancellation, composite-trust-query, payment-evidence-frame) | Reference implementations (Apache 2.0)                                                                                        | `jcs-rfc8785-v1` |
| [`algovoi-audit-verifier`](https://github.com/chopmob-cloud/algovoi-audit-verifier) (PyPI + npm + GitHub)                                                                                                           | Independent auditor verifier (Apache 2.0)                                                                                     | `jcs-rfc8785-v1` |
| [`chopmob-cloud/algovoi-jcs-conformance-vectors`](https://github.com/chopmob-cloud/algovoi-jcs-conformance-vectors)                                                                                                 | open conformance corpus, 8-implementation cross-validation matrix (880/880 byte-for-byte directly executed, as of 2026-06-18) | `jcs-rfc8785-v1` |

### Vauban Pay (seritalien, egoriklok)

| Surface                                                                                                          | Type                             | Anchor citation                                                |
| ---------------------------------------------------------------------------------------------------------------- | -------------------------------- | -------------------------------------------------------------- |
| [`draft-vauban-x402-stark-receipts`](https://datatracker.ietf.org/doc/draft-vauban-x402-stark-receipts/)         | IETF I-D, Independent Submission | `urn:x402:canonicalisation:jcs-rfc8785-v1` (explicit)          |
| [`draft-vauban-x402-lifecycle-fsm`](https://datatracker.ietf.org/doc/draft-vauban-x402-lifecycle-fsm/)           | IETF I-D, Independent Submission | RFC 8785 + "JCS canonical preimage discipline" (URN not cited) |
| [`draft-vauban-x402-vpsf-algebra`](https://datatracker.ietf.org/doc/draft-vauban-x402-vpsf-algebra/)             | IETF I-D, Independent Submission | RFC 8785 + "JCS canonical preimage discipline" (URN not cited) |
| [`draft-vauban-x402-starknet-anchor`](https://datatracker.ietf.org/doc/draft-vauban-x402-starknet-anchor/)       | IETF I-D, Independent Submission | RFC 8785 (URN not cited)                                       |
| [`draft-vauban-x402-delegation-binding`](https://datatracker.ietf.org/doc/draft-vauban-x402-delegation-binding/) | IETF I-D, Independent Submission | RFC 8785 + "JCS canonical preimage discipline" (URN not cited) |
| [`draft-vauban-x402-pqc-receipts`](https://datatracker.ietf.org/doc/draft-vauban-x402-pqc-receipts/)             | IETF I-D, Independent Submission | RFC 8785 + "JCS canonical preimage discipline" (URN not cited) |

### Sato / Soos

| Surface                                                                          | Type                             | Anchor                                                              |
| -------------------------------------------------------------------------------- | -------------------------------- | ------------------------------------------------------------------- |
| [`draft-sato-soos-mjwt`](https://datatracker.ietf.org/doc/draft-sato-soos-mjwt/) | IETF I-D, Independent Submission | Out of scope (broader agentic-AI authorisation; Mandate JWT format) |

### Crest Deployment Systems LLC (Andy Salvo)

| Surface                                                                                                                                                                                                            | Type                                                                      | Anchor                                     |
| ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ | ------------------------------------------------------------------------- | ------------------------------------------ |
| `urn:crest:trust-check-v1` at [`verify.crestsystems.ai`](https://verify.crestsystems.ai)                                                                                                                           | Hosted general-service-trust envelope                                     | `urn:x402:canonicalisation:jcs-rfc8785-v1` |
| `urn:crest:service_trust_v0` at [`chopmob-cloud/algovoi-jcs-conformance-vectors`](https://github.com/chopmob-cloud/algovoi-jcs-conformance-vectors/tree/main/vectors/service_trust_v0) (vectors merged 2026-05-24) | Conformance vector set (downstream-adopter)                               | `urn:x402:canonicalisation:jcs-rfc8785-v1` |
| [`andysalvo/action-ref-verify`](https://github.com/andysalvo/action-ref-verify)                                                                                                                                    | Independent verifier + 12-vector conformance corpus + Node/Python runners | `urn:x402:canonicalisation:jcs-rfc8785-v1` |

### PEAC Protocol

| Surface                                                                                                                                   | Type                                       | Anchor                                                                 |
| ----------------------------------------------------------------------------------------------------------------------------------------- | ------------------------------------------ | ---------------------------------------------------------------------- |
| [`peacprotocol/peac` AP2 OMH fixture set](https://github.com/peacprotocol/peac/tree/main/specs/conformance/interop/ap2-open-mandate-hash) | 5-vector AP2 mandate-reference fixture set | `urn:x402:canonicalisation:jcs-rfc8785-v1` (via AP2 OMH v0 derivation) |

## By canonicalisation anchor

No document published in x402 namespace pins a different canonicalisation URN; the substrate is **uni-anchor** in URN registration as of the registry revision below.

| Anchor URN                                                                       | Documents citing                                                                               | Status                                         |
| -------------------------------------------------------------------------------- | ---------------------------------------------------------------------------------------------- | ---------------------------------------------- |
| `urn:x402:canonicalisation:jcs-rfc8785-v1`                                       | 8 IETF I-Ds (7 AlgoVoi + 1 Vauban) + 4 published specs / hosted endpoints / fixture sets       | Sole substrate URN in active use               |
| RFC 8785 + "JCS canonical preimage discipline" terminology, without URN citation | 5 Vauban I-Ds (lifecycle-fsm, vpsf-algebra, starknet-anchor, delegation-binding, pqc-receipts) | Implementation-compatible, citation-incomplete |

The 5 Vauban I-Ds in the second row use the discipline as encoded by `draft-hopley-x402-canonicalisation-jcs-v1` (including the schema-normalisation rules extending RFC 8785 -- integer-millisecond timestamps, ordered arrays as significant, in-band `canon_version` pin) but cite only RFC 8785 in Normative References, not the AlgoVoi-authored I-D where the discipline is registered. A normative reference to `draft-hopley-x402-canonicalisation-jcs-v1` or the `urn:x402:canonicalisation:jcs-rfc8785-v1` URN in next revisions would make the citation unambiguous and consistent with `draft-vauban-x402-stark-receipts`, which already cites it explicitly.

Any future document publishing a **different** canonicalisation URN would create a substrate fork; the substrate-author position is committed to maintaining a single canonical anchor and welcomes substrate-layer alignment proposals before any divergence.

## Cross-reference: Adopters Registry

Parties publishing artefacts under `urn:x402:canonicalisation:jcs-rfc8785-v1` are listed in the [Substrate Adopters Registry](/adopters). The Adopters Registry is the operational record of observed adoption; this Document Index is the bibliographic record of documents in the namespace.

Both surfaces are maintained by AlgoVoi as the substrate author. Authorship of artefacts and authorship of the canonicalisation discipline are separate facts; both surfaces record both.

## Cross-impl validation

The 8-implementation cross-validation matrix is the operational evidence of canonicalisation-discipline interop. As of 2026-05-25:

| Layer                | Vector sets                          | Implementations                                         | Total agreements            |
| -------------------- | ------------------------------------ | ------------------------------------------------------- | --------------------------- |
| JCS canonicalisation | 8 (original 7 + PEF set, 2026-05-30) | 8 (Python, TypeScript, Go, Rust, Java, PHP, .NET, Ruby) | **576 / 576** byte-for-byte |

Attestation: [`_attestations/2026-05-25-8-impl-5-format-cross-validation.md`](https://github.com/chopmob-cloud/algovoi-jcs-conformance-vectors/blob/main/_attestations/2026-05-25-8-impl-5-format-cross-validation.md) (JCS); [`_attestations/2026-05-30-8-impl-cross-validation.md`](https://github.com/chopmob-cloud/algovoi-pef/blob/main/_attestations/2026-05-30-8-impl-cross-validation.md) (PEF).

Any new document anchoring to this URN inherits the same cross-impl validation discipline by construction; vector sets for the new document slot into the 8-impl runner suite mechanically.

## Maintenance

This index is observed at the time of the most recent revision below. New entries are added via:

1. **Pull request** against [`chopmob-cloud/docs`](https://github.com/chopmob-cloud/docs), editing this page (`x402-document-index.mdx`).
2. **GitHub issue** at [`chopmob-cloud/algovoi-jcs-conformance-vectors/issues`](https://github.com/chopmob-cloud/algovoi-jcs-conformance-vectors/issues/new) titled `x402 document index submission: {document identifier}`.
3. **Email** to [hello@algovoi.co.uk](mailto:hello@algovoi.co.uk) with subject `x402 document index submission`.

To qualify for inclusion, a document MUST:

* Anchor to `urn:x402:canonicalisation:jcs-rfc8785-v1` in-band (via `canon_version` field, normative reference, or equivalent unambiguous citation).
* Be published in a publicly-citable surface (IETF datatracker, package registry, GitHub repository, hosted endpoint, or DID-anchored URL).

The index records the inclusion fact, not co-authorship of the substrate or endorsement of the document's content.

## Revision history

| Date               | Change                                                                                                                                                                                                                                                                                                                                                                                                              |
| ------------------ | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| 2026-05-25         | Initial publication. 7 IETF I-Ds + 4 published specs / fixture sets indexed.                                                                                                                                                                                                                                                                                                                                        |
| 2026-05-25 (rev 2) | Expanded to 13 IETF I-Ds. Added 5 additional Vauban-authored I-Ds (lifecycle-fsm, vpsf-algebra, starknet-anchor, delegation-binding, pqc-receipts) plus draft-sato-soos-mjwt. Added canonicalisation anchor-citation coverage section: 7 of 12 in-scope receipt-format I-Ds cite the URN explicitly; 5 reference the discipline by RFC 8785 + "JCS canonical preimage discipline" terminology without URN citation. |
| 2026-05-30         | **14 IETF I-Ds** as of today. Added `draft-hopley-x402-payment-evidence-frame-00` (AlgoVoi, 7th sole-authorship I-D, posted 2026-05-30). Updated `draft-hopley-x402-canonicalisation-jcs-v1` to current revision -04 (2026-05-29). Updated AlgoVoi count 6 → 7; URN-citing count 7 → 8; in-scope I-D total 12 → 13. Cross-impl validation updated to 576/576 across 8 vector sets.                                  |