algovoi-substrate v0.4.0 | Apache 2.0 | settlement_action_binding_v1 binds a settlement attestation to the verified agent action it settles

[chopmob-cloud]

We have published algovoi-substrate v0.4.0 as Apache 2.0, adding settlement_action_binding_v1.

A settlement attestation proves a payment happened. On its own it does not prove which verified agent action the payment settles, nor that the correspondence is recorded in a tamper-evident chain. This release closes that gap with one hash, four fields, verifiable offline by any party with SHA-256 and a JSON parser:

binding_ref = "sha256:" + SHA-256(JCS({action_ref, transition_hash, settlement_ref, retention_chain_ref}))

No new hashing primitive is introduced. It composes four already-published substrate artifacts: the verified action identity (action_ref), the COMMITTED lifecycle transition (transition_hash), the settlement attestation content hash (settlement_ref), and the retention chain position (retention_chain_ref). JCS is RFC 8785; the hash is SHA-256.

Spec: draft-hopley-x402-retention-chain, Section 7.6 (Settlement-Action Binding) and Section 8.9 (binding vectors).

pip install algovoi-substrate==0.4.0
npm install @algovoi/substrate@0.4.0

Conformance corpus at chopmob-cloud/algovoi-jcs-conformance-vectors:

settlement_action_binding_v1 provides 6 reference vectors + 5 pair invariants: binding stability, settlement binding, action binding, state binding (only a COMMITTED transition binds), and chain binding.

48 byte-level cross-references: every vector verified independently across 8 implementations (Python, Node, Ruby, PHP, Go, Rust, Java, .NET) against the same canonical bytes. Reference binding_ref: sha256:7dc4a2bf62b3c5eabd10fc875ff7fc10f188666f15838c4a51464cc72e80f6ca.

This is L1 substrate work, maintained and kept stable. Adopters who pin to algovoi-substrate==0.4.0 will see more advancements over the coming weeks, with no breaking changes to the hash construction. Pinned adopters get continuity guarantees that open range installs do not. If you are building L2 on top (mandate lifecycle, settlement flows, receipt families), we are here to support that work, and attributed L2 is taken into account as the L1 substrate evolves.

If you want help verifying your binding_ref output against the canonical vectors, or have questions about composing the binding into your settlement flow, email chopmob@gmail.com. That is a genuine offer, not a pitch.