The JCS canonicalisation substrate for agentic payments

AlgoVoi authors the open JCS (RFC 8785) canonicalisation discipline and the verifiable, offline-verifiable compliance-receipt formats that let an agent payment be re-derived and checked by anyone — across x402, AP2, A2A and MPP, on one shared substrate, with zero customer PII.

What the substrate defines

If two systems serialise the same JSON differently they hash to different bytes, and a receipt cannot be independently verified. JSON Canonicalization Scheme (RFC 8785) fixes one byte sequence per object; over it, SHA-256 gives a stable, content-addressed reference. That is what makes a receipt checkable by a third party or a regulator, not only by the issuer.

• action_ref — SHA-256(JCS({agent_id, action_type, scope, timestamp_ms})): a content-addressed reference to a payment action, recomputable from the disclosed fields alone.
• Compliance receipt — categorical ALLOW / REFER / DENY screening outcome, signed and no-PII.
• Settlement attestation — binds the on-chain settlement to the same action_ref.
• Retention chain — a self-verifiable audit chain for statutory record-keeping (MiCA / DORA).
• RFC 9421 signing base — the canonical signing input for HTTP message signatures across a proxy chain.

One receipt layer for every protocol

Each protocol answers how an AI agent pays; AlgoVoi answers how you prove the payment was screened, authorised and settled. All four resolve to the same receipt grammar over the same canonical bytes.

What's in a receipt

• Categorical ALLOW / REFER / DENY — the screening outcome as an enumeration, not raw customer data.
• Deterministic & recomputable — canonicalised under JCS (RFC 8785); anyone can re-derive the hash.
• Offline-verifiable — cryptographically signed; verification needs no live call back to AlgoVoi.
• Zero customer PII — audit-grade evidence that the check ran, without exposing the customer.

Verifiable x402 agentic payment receipt

An x402 payment receipt is an offline-verifiable, no-PII record binding the payment execution to the exact authorisation that approved it, recomputable from the receipt alone with JCS (RFC 8785) and SHA-256 and no AlgoVoi software. Three reference pages on the receipt construction and verification:

• Verifiable x402 receipt — receipt format, preimage construction, and Ed25519 signature verification with no AlgoVoi code in the trust base.
• Offline-verifiable receipts — step-by-step offline verification: preimage derivation, Ed25519 signature check, and optional Falcon-1024 post-quantum layer.
• No-PII compliance receipt — how the compliance gate verdict feeds the receipt so a recipient verifies that no personal data was included, recomputable from the receipt alone.

Agentic lifecycle: identity to settlement

The AlgoVoi Keystone is the agentic lifecycle and agentic-payment trust chain -- six content-addressed references in strict composition over JCS (RFC 8785) and SHA-256, from identity through execution to one verifiable verdict:

passport_ref → mandate_ref → policy_bound_ref → decision_ref → execution_ref → trust_query_ref

Each reference is sha256: over JCS of its predecessor; recompute any field and every downstream reference diverges. The agentic lifecycle extends through the full post-decision sequence: settlement binds to the exact execution_ref produced; refund anchors to the same; an audit chain of frames links all three by prev_hash and caps them with one trust_query_ref. Any party recomputes the full lifecycle offline -- JCS (RFC 8785) and SHA-256, no AlgoVoi software in the trust base.

Full lifecycle reference and composition proofs: docs.algovoi.co.uk/keystone

Open, and verifiable yourself

The conformance vectors are published under Apache-2.0 and cross-validated byte-identical across eight independent implementations in eight languages — Python, Node.js, Go, Rust, Java, PHP, .NET and Ruby.

• Conformance vectors & verifier: algovoi-jcs-conformance-vectors
• Receipt verifier: algovoi-receipt-verifier
• RFC 9421 signer · verifier

Adopt the substrate

Building on agentic payments? You do not need to re-derive the canonicalisation, the action references, or the receipt formats. Take the open base, confirm byte-parity, keep the attribution. Three steps:

1. Install the reference implementation: pip install algovoi-substrate or npm i @algovoi/substrate.
2. Verify byte-parity against the published conformance vectors (content-addressed, manifest 0.15.0): confirm your implementation reproduces the pinned digests across the receipt sets.
3. Reference the discipline by its identifier urn:x402:canonicalisation:jcs-rfc8785-v1 and keep the Apache-2.0 NOTICE. Then build your product on top.

That is the whole ask: attribute the L1, import by hash, and your interop stays guaranteed as the substrate evolves. Full guide: Adopt the substrate.

Standards — dated IETF Internet-Drafts

• draft-hopley-x402-canonicalisation-jcs-v1 — the canonicalisation discipline.
• draft-hopley-x402-compliance-receipt — the compliance receipt format.
• draft-hopley-x402-settlement-attestation — settlement evidence.

FAQ

What is the JCS canonicalisation substrate?

AlgoVoi's open discipline that pins JCS (RFC 8785) as the canonical preimage form for agentic-payment receipts, so the same object serialises to identical bytes everywhere and re-verifies years later.

What is action_ref?

SHA-256(JCS({agent_id, action_type, scope, timestamp_ms})) — a content-addressed reference to a payment action, recomputable from the disclosed fields, binding the agent, the action and the settlement.

How are agentic payment receipts verified?

Offline: recompute the canonical bytes and check the signature with the open verifier — no live call to AlgoVoi, no customer PII.

Available for acquisition

AlgoVoi — the open substrate, the published Apache-2.0 packages, the IETF Internet-Drafts, the production multi-chain payment gateway, and the post-quantum, offline-verifiable compliance-evidence application suite — is available for acquisition as a clean asset transfer. Sole ownership, no investors, no debt.

Full asset overview: docs.algovoi.co.uk/acquisition. Direct enquiries, with pricing and the diligence pack under NDA: chopmob@gmail.com.