Reference

Architecture

What the platform is actually made of, package by package, as it stands today.

The system is a workspace of small packages behind one contract. The vocabulary lives in one place and everything conforms to it, vendor and protocol names appear only at the layer that binds to them, and the composition root is a package of its own so that what is wired together is inspectable rather than implied.

The spine

The parts everything else is defined against. If you read only one group, read this one.

surface: The canonical, transport-agnostic contract. The vocabulary lives here and every implementation conforms to it.
core: The governance spine: the deny-first gate and what it reasons over.
gateway: The composition root. What is wired to what is stated here rather than discovered by reading imports.
server: The hosted side, and the only thing with authority to settle.
store: Durable persistence for the money path.
sdk: The embeddable client implementing the same contract.
metamodel: The protocol described as data, with the generators that derive from it.

Authority and identity

Who is asking, what they were permitted to do, and how that permission is proven, narrowed and withdrawn.

agentauth: The protocol layer under agent authentication.
disclosure: A vendor-neutral signed statement of what an actor is and may do.
vc-mandate: A mandate expressed as a verifiable-credential delegation.
erc7710: Delegated authority enforced by contract.
erc8004: A read-only reader for the onchain agent registries. It never writes.
identity-graph: Joins the parallel identity systems into one view and reports how much of it is corroborated. It will not conclude that an identity is verified.
revocation: Identity-scoped revocation over a published status list.
session: The multi-party, composition-safe governance core.
authority-coverage: Whether the authority actually covers what is being attempted.
observe: The split between the right to watch and the right to act.
custody: Hosted signing that keeps settle-separation intact.
challenge: A bonded challenge process, so an enforcement claim can be contested with money at stake.
claims: A typed registry of decision claims with stable meanings.

Limits

The arithmetic a decision is made of.

caps: Adaptive cap inputs.
periodic-limits: Standing spend authority as a control parameter.
irreversible-outlay: The bound on how much of a mandate may be spent unrecoverably.
concentration: A per-counterparty concentration bound.
credit: Underwriting for extending credit to an agent.
stake: Bonded collateral with slashing scaled to blast radius.
insurance: A verifiable risk-pool backstop behind the money layer.
economics: The economic-state plane the above reason over.

Moving money

Rails, and everything that has to be true for value to move correctly across them.

rails: The settlement rails behind the settler.
l402: The Lightning binding.
erc5792: Batched onchain calls that succeed together or not at all.
psp: A vendor-neutral abstraction for the card rail.
compose: Atomic multi-rail composition with deterministic rollback.
settlement-delay: Value-scaled delay that keeps revocation reachable in time.
authhold: Authorise now, capture later.
clearing: The evidence and clearing band between deciding and resolving.
split: One payment in, several parties owed.
metering: Governed metering and streaming.
negotiation: A governed bound on what may be agreed.
dispute: The dispute and remediation lifecycle before a payout.
compelling-evidence: What we hold about a payment, packaged for a dispute, with a verdict that can say it will probably not succeed.
resolve: Counterparty resolution.
service-terms: The counterparty's own signed terms.
commerce: The commerce tier above payment.
bank-rails: ACH and wire: deferred against instant finality, return windows, cutoffs and business days.
discovery: Reads what a merchant publishes about itself and grades it as the self-report it is.
merchant-policy: The seller's side of the decision: which agents it will sell to, and under what conditions.
attribution: Which agent, through which platform, from which referral, as a signed claim bound to the payment.

Protocol bindings

Where vendor and protocol names are allowed to appear, and nowhere else.

a2a: Agent-to-agent tasks, projected onto the contract.
ap2: The Agent Payments Protocol interop boundary.
visa-tap: The Visa Trusted Agent Protocol adapter.
mcp: A curated tool projection for agents.
xmtp: Inbound payment-intent ingest over encrypted messaging.
scitt: Rendering the record into the standard published-record format.

The record

Producing it, publishing it, and proving it without our help.

enforcement: The enforcement record as a first-class object.
audit-verify: Independent verification of an exported chain.
portable-proof: A record that survives on its own.
transparency: An append-only Merkle log.
webhooks: Outbound signed webhooks derived from the same chain.
otel: The tracing edge.
observe: What may be watched, as distinct from what may be done.

Assurance

How we find out we are wrong before you do.

formal: A machine-checked model of the deny-first gate.
conformance: Structural and behavioural self-checks over the whole surface.
spec-test: The event-surface drift gate.
eval: A payment-native evaluation layer.
simulate: Counterfactual replay of a mandate against what actually happened.
scenario-machine: End-to-end demonstrations with machine actors.
validation: Validation supply, and a guard on what is read back.
oversight: Measurement of the human-in-the-loop layer.
throughput: The measured benchmark. It publishes what the decision path actually sustains, including where it does not.

Memory

Because an agent that transacts needs to remember, and a memory that cannot be verified is a liability.

memory: A verifiable, bi-temporal, content-addressed store.
memory-lifecycle: The governed lifecycle over that store.

And outside the platform

The specification is published on its own, and the clients are generated from it: typescript, python, go and rust, plus the operator command line and the agent-facing tool server. That is why the same call has the same shape in every one of them.