algovoi-composite-trust-query

AlgoVoi-authored reference implementation for the composite trust query response format specified in IETF Internet-Draft draft-hopley-x402-composite-trust-query (Independent Submission, Informational).

Verifier-side categorical conclusion over an audit chain composed of compliance, settlement, cancellation, and refund receipts. Closed four-element enumeration {TRUSTED, PROVISIONAL, INSUFFICIENT_EVIDENCE, UNTRUSTED} captures the operationally-distinct four-state decision space: proceed, proceed-with-caution, hold-pending-more-data, halt.

Top-of-stack format above the four AlgoVoi receipt formats under the shared canonicalisation discipline (urn:x402:canonicalisation:jcs-rfc8785-v1).

Python and TypeScript reference implementations, byte-for-byte parity, Apache 2.0.

Lifecycle position

admission     settlement     cancellation    refund (if owed)
compliance -> settlement  -> cancellation -> refund
receipt       attestation    receipt         receipt
                              |
                              v   (chain_ref)
                          CTQ response (TRUSTED | PROVISIONAL | INSUFFICIENT_EVIDENCE | UNTRUSTED)

A verifier walks the audit chain, applies a structured query, and emits a single composite-trust-claim response anchoring the chain by its content-addressed root. Regulators, dashboards, and downstream agents consume one byte-deterministic statement rather than re-walking the underlying chain. The chain remains independently verifiable at the chain_ref content-address.

Packages

Both depend on algovoi-substrate / @algovoi/substrate for the JCS canonicalisation primitive.

Quick start

Python

from algovoi_composite_trust_query import build_ctq_response
from algovoi_substrate import sha256_jcs

r = build_ctq_response(
    trust_outcome="TRUSTED",
    chain_ref="sha256:0dd5d0b76c9b9281fdeb2509ad38ab132b16a17385ca01d976ff9e6e12563a0f",
    query_ref="sha256:8b7df143d91c716ecfa5fc1730022f6b421b05cedee8fd52b1fc65a96030ad52",
    ctq_timestamp_ms=1716494400000,
    verifier_did="did:web:api.algovoi.co.uk",
    jurisdiction_flags=["UK", "EU"],
)
print(sha256_jcs(dict(r)))

TypeScript

import { buildCtqResponse } from "@algovoi/composite-trust-query";
import { sha256Jcs } from "@algovoi/substrate";

const r = buildCtqResponse({
  trust_outcome: "TRUSTED",
  chain_ref:
    "sha256:0dd5d0b76c9b9281fdeb2509ad38ab132b16a17385ca01d976ff9e6e12563a0f",
  query_ref:
    "sha256:8b7df143d91c716ecfa5fc1730022f6b421b05cedee8fd52b1fc65a96030ad52",
  ctq_timestamp_ms: 1716494400000,
  verifier_did: "did:web:api.algovoi.co.uk",
  jurisdiction_flags: ["UK", "EU"],
});
console.log(sha256Jcs(r));

Response format

Seven-field JSON object canonicalised under RFC 8785 (JCS):

Closed enumeration: trust_outcome

The four-value enum is byte-load-bearing under RFC 8785: each value produces a byte-distinct content_hash. Collapsing to three values loses the operationally-distinct INSUFFICIENT_EVIDENCE state ("we couldn't verify either way") from UNTRUSTED ("we verified and the answer is no"), which matters for operator dashboards, regulator reporting, and downstream automated decision-making.

Conformance vectors

8 byte-level reference vectors + 7 pair invariants + 3 chain invariants at vectors/composite_trust_query_v1/.

Companion IETF Internet-Draft

draft-hopley-x402-composite-trust-query (Independent Submission, Informational). AlgoVoi-authored. Normatively references draft-hopley-x402-canonicalisation-jcs-v1. Welcomes downstream-adopter contributions per the Appendix C "Known Adopters" pattern.

What this is NOT

• Not a receipt. Receipts record events that happened; a CTQ response records a verifier's categorical conclusion over an event chain. Receipts are emitted by participants in the event; CTQ responses are emitted by verifiers reading the chain.
• Not the query itself. The query that was asked is identified by query_ref (content-addressed). The query format is opaque to the response format; callers MAY use any structured-question encoding.
• Not a chain-finality model. The verifier applies whatever finality semantics its risk model requires; the response records the verifier's categorical conclusion, not the underlying finality model.

Related AlgoVoi packages

Conformance to the canonicalisation discipline

This package emits composite-trust-query responses pinned to canon_version: jcs-rfc8785-v1 on every emitted response. The pin is in-band; downstream consumers (including algovoi-audit-verifier and any conformant third-party verifier) read the pin to select the canonicalisation rule applied at emission.

The pin is the load-bearing primitive for the Substrate Adopters Registry: adopters anchoring to this discipline pin the same canon_version value in their own publicly-citable artefacts. AlgoVoi maintains the registry as a neutral observer; this package itself is recorded there as the AlgoVoi reference implementation.

Substrate adopters

AlgoVoi is recorded in the Substrate Adopters Registry as the substrate author (v1 and v2). Parties anchoring their own services or specifications to canon_version: jcs-rfc8785-v1 are recorded in the registry via the submission process. AlgoVoi validates submissions against the artefact's canonical bytes and adds qualifying entries.

Licence

Apache 2.0.