PAYMENTS SIGNAL REFERENCE ARCHITECTURE · SYNTHETIC / TRAINING ONLY

CBDC, stablecoin, tokenised-deposit, FX, payment-versus-payment, CLS, trade-finance, and alternative cross-border architecture

Compare the claim, ledger, access, interoperability, foreign-exchange, delivery-versus-payment, and redemption boundaries before calling a token transfer settlement.

Payments Signal reference architecture v1 · reviewed 2026-07-23

Reference architecture—not a scheme mandate. This blueprint compares architectural questions across foreign-exchange settlement, central-bank digital currency, tokenised deposits, stablecoins, tokenised assets, and trade obligations. It does not say these instruments are equivalent, authorised, interoperable, final, backed, redeemable, or suitable for production.

Audience and purpose

Payment and digital-money architects, central-bank and commercial-bank teams, treasury, foreign-exchange, trade-finance, risk, legal, and business-analysis teams.

Components

Customer, institution, or market participant

Holds a legal claim or authorised access and initiates payment, exchange, redemption, or trade settlement.

Kind
actor
Owner
Participating customer or institution
Responsibilities
  • Prove authority over the relevant account, wallet, asset, or obligation
  • Understand which entity owes the claim
Inputs
  • Authorised business instruction and correlated state
Outputs
  • Versioned result, status, and audit evidence
Controls
  • Participant eligibility
  • Identity and entitlement
  • Jurisdiction and product rules
Failure modes
  • Wrong participant or wallet
  • Unauthorised transfer
  • Claim misunderstood
Recovery
  • Stop the instruction
  • Restore authority and correct ownership records under the governing arrangement
Non-functional requirements
  • Durable correlation through stable business and technical identifiers
  • Capacity and availability matched to the service-level objective
  • Auditable state changes, configuration, and operator actions

Access, wallet, custody, and participant gateway

Protects keys or account access, validates participant eligibility, and submits signed or authenticated instructions.

Kind
gateway
Owner
Wallet, custodian, bank, or infrastructure participant
Responsibilities
  • Separate customer authority from operator authority
  • Protect key, account, and transaction context
Inputs
  • Authorised business instruction and correlated state
Outputs
  • Versioned result, status, and audit evidence
Controls
  • Identity and entitlement
  • Key or credential lifecycle
  • Transaction integrity
  • Replay prevention
Failure modes
  • Lost key
  • Custody outage
  • Compromised participant
Recovery
  • Suspend access without destroying the underlying claim
  • Recover through the arrangement's authorised process
Non-functional requirements
  • Durable correlation through stable business and technical identifiers
  • Capacity and availability matched to the service-level objective
  • Auditable state changes, configuration, and operator actions

Money or settlement-asset issuer

Defines the claim, issuance, redemption, backing, liability, and holder rights for central-bank money, tokenised deposits, or stablecoins.

Kind
external-network
Owner
Central bank, commercial bank, or arrangement issuer
Responsibilities
  • Issue and redeem only under governing rules
  • Keep liability, backing, and holder claim explicit
Inputs
  • Authorised business instruction and correlated state
Outputs
  • Versioned result, status, and audit evidence
Controls
  • Issuance authority
  • Backing or reserve control
  • Reconciliation and attestation
  • Redemption terms
Failure modes
  • Unbacked issuance
  • Redemption suspended
  • Issuer and ledger records diverge
Recovery
  • Stop issuance
  • Reconcile liabilities and backing
  • Apply resolution and holder-protection arrangements
Non-functional requirements
  • Durable correlation through stable business and technical identifiers
  • Capacity and availability matched to the service-level objective
  • Auditable state changes, configuration, and operator actions

Token, account, or settlement ledger

Records ownership or account balances and the state transition that the arrangement recognises.

Kind
ledger
Owner
Ledger or settlement-system operator
Responsibilities
  • Apply an authorised state transition once
  • Record ordering, finality condition, and reversal or correction authority
Inputs
  • Authorised business instruction and correlated state
Outputs
  • Versioned result, status, and audit evidence
Controls
  • Consensus or central ordering
  • No double spend
  • Balance conservation
  • Finality rule
Failure modes
  • Fork or inconsistent state
  • Duplicate transfer
  • Finality ambiguity
Recovery
  • Pause unsafe finalisation
  • Recover from an agreed checkpoint
  • Reconcile participant and issuer records
Non-functional requirements
  • Durable correlation through stable business and technical identifiers
  • Capacity and availability matched to the service-level objective
  • Auditable state changes, configuration, and operator actions

Interoperability and bridge boundary

Moves an instruction or representation between ledgers, account systems, jurisdictions, or technology stacks without pretending the two assets are the same.

Kind
gateway
Owner
Arrangement operators and participants
Responsibilities
  • Name lock, burn, mint, escrow, prefunding, messaging, and legal mechanisms precisely
  • Prevent value creation from inconsistent cross-system state
Inputs
  • Authorised business instruction and correlated state
Outputs
  • Versioned result, status, and audit evidence
Controls
  • Two-sided state proof
  • Supply conservation
  • Timeout and rollback
  • Operator and legal responsibility
Failure modes
  • Source locked but target not issued
  • Bridge compromise
  • Duplicate representation
Recovery
  • Stop bridge processing
  • Prove both sides before release
  • Use governed compensation or redemption
Non-functional requirements
  • Durable correlation through stable business and technical identifiers
  • Capacity and availability matched to the service-level objective
  • Auditable state changes, configuration, and operator actions

Foreign-exchange matching and payment-versus-payment control

Links two currency legs so final transfer of one occurs only with final transfer of the other under the arrangement.

Kind
control
Owner
FX settlement system or linked operators
Responsibilities
  • Match both legs and participants
  • Enforce payment-versus-payment rather than merely simultaneous message submission
Inputs
  • Authorised business instruction and correlated state
Outputs
  • Versioned result, status, and audit evidence
Controls
  • Trade and instruction match
  • Currency-leg readiness
  • Liquidity and cut-off
  • Atomic or conditional finality
Failure modes
  • One leg ready and the other missing
  • Liquidity shortfall
  • Cut-off missed
Recovery
  • Keep both legs unsettled where the model permits
  • Resolve liquidity or cancel under the governing rules
Non-functional requirements
  • Durable correlation through stable business and technical identifiers
  • Capacity and availability matched to the service-level objective
  • Auditable state changes, configuration, and operator actions

Asset, document, or trade obligation

Represents the security, commodity, invoice, document, or trade obligation exchanged against payment.

Kind
ledger
Owner
Market infrastructure, custodian, registry, or trade platform
Responsibilities
  • Prove entitlement and transfer conditions
  • Link delivery state to the cash leg where delivery-versus-payment is intended
Inputs
  • Authorised business instruction and correlated state
Outputs
  • Versioned result, status, and audit evidence
Controls
  • Asset authenticity
  • Transfer restriction
  • Delivery-versus-payment condition
  • Document and title control
Failure modes
  • Asset unavailable
  • Document discrepancy
  • Cash and asset states diverge
Recovery
  • Hold both legs when possible
  • Open an exception with legal and operational ownership
Non-functional requirements
  • Durable correlation through stable business and technical identifiers
  • Capacity and availability matched to the service-level objective
  • Auditable state changes, configuration, and operator actions

Policy, compliance, risk, and privacy controls

Applies participation, financial-crime, data, monetary, prudential, consumer, and market rules appropriate to the arrangement.

Kind
control
Owner
Issuer, participant, operator, compliance, legal, and risk owners
Responsibilities
  • Apply controls to the actual parties, claims, assets, and jurisdictions
  • Keep privacy and audit requirements compatible
Inputs
  • Authorised business instruction and correlated state
Outputs
  • Versioned result, status, and audit evidence
Controls
  • Sanctions and anti-money-laundering
  • Limits and eligibility
  • Privacy and disclosure
  • Governance and change
Failure modes
  • Pseudonym treated as anonymous
  • Control absent at bridge
  • Rule conflicts across jurisdictions
Recovery
  • Hold or reject under authority
  • Escalate legal conflict
  • Preserve evidence without unnecessary disclosure
Non-functional requirements
  • Durable correlation through stable business and technical identifiers
  • Capacity and availability matched to the service-level objective
  • Auditable state changes, configuration, and operator actions

Liquidity, settlement, reconciliation, and incident operations

Monitors positions, funding, ledger state, bridge state, redemption, both FX legs, asset delivery, and external account evidence.

Kind
operations
Owner
Arrangement and participant operations
Responsibilities
  • Identify the last confirmed state on every ledger and claim
  • Reconcile issuance, backing, settlement, redemption, and external cash
Inputs
  • Authorised business instruction and correlated state
Outputs
  • Versioned result, status, and audit evidence
Controls
  • Multi-ledger reconciliation
  • Liquidity thresholds
  • Incident authority
  • No unsupported replay
Failure modes
  • Token moves but bank cash does not
  • Redemption queue ages
  • One FX leg uncertain
Recovery
  • Freeze affected path
  • Trace every claim and ledger
  • Recover under the arrangement's legal and technical rules
Non-functional requirements
  • Durable correlation through stable business and technical identifiers
  • Capacity and availability matched to the service-level objective
  • Auditable state changes, configuration, and operator actions

Interfaces

Authorised instruction

ev-user → ev-access

Submit payment, exchange, delivery, redemption, or issuance intent.

Contract
api · synchronous
Controls
  • Authentication and authorisation
  • Integrity and replay protection
  • Correlation and audit evidence
Failure treatment
Reject unclear authority or unsupported asset and jurisdiction.

Eligibility and control request

ev-access → ev-compliance

Apply participant, transaction, asset, and jurisdiction controls.

Contract
control · synchronous
Controls
  • Authentication and authorisation
  • Integrity and replay protection
  • Correlation and audit evidence
Failure treatment
Hold when required controls are unavailable or inconclusive.

Controlled ledger instruction

ev-compliance → ev-ledger

Release an authorised state transition.

Contract
control · asynchronous
Controls
  • Authentication and authorisation
  • Integrity and replay protection
  • Correlation and audit evidence
Failure treatment
Preserve rejected, held, and expired states.

Issuance and redemption authority

ev-instrument → ev-ledger

Change instrument supply or liability under governing rules.

Contract
posting · synchronous
Controls
  • Authentication and authorisation
  • Integrity and replay protection
  • Correlation and audit evidence
Failure treatment
Stop supply change when backing, authority, or reconciliation is uncertain.

Source-ledger state proof

ev-ledger → ev-interoperability

Prove lock, burn, final transfer, or other source condition.

Contract
event · asynchronous
Controls
  • Authentication and authorisation
  • Integrity and replay protection
  • Correlation and audit evidence
Failure treatment
Do not create target value from incomplete or unverified source state.

Target-ledger action

ev-interoperability → ev-ledger

Complete the governed cross-system action without duplicating supply.

Contract
posting · asynchronous
Controls
  • Authentication and authorisation
  • Integrity and replay protection
  • Correlation and audit evidence
Failure treatment
Use timeout and compensation rules for incomplete two-sided state.

Currency-leg readiness

ev-ledger → ev-fx-pvp

Make each matched currency leg ready for conditional settlement.

Contract
settlement · asynchronous
Controls
  • Authentication and authorisation
  • Integrity and replay protection
  • Correlation and audit evidence
Failure treatment
Keep the pair unsettled when required readiness or liquidity is missing.

PvP settlement release

ev-fx-pvp → ev-ledger

Finalise both currency legs under the arrangement's PvP rule.

Contract
settlement · synchronous
Controls
  • Authentication and authorisation
  • Integrity and replay protection
  • Correlation and audit evidence
Failure treatment
Record and resolve any residual uncertainty before participant credit.

Delivery-versus-payment condition

ev-ledger → ev-asset-leg

Coordinate cash and asset delivery when the arrangement supports it.

Contract
settlement · synchronous
Controls
  • Authentication and authorisation
  • Integrity and replay protection
  • Correlation and audit evidence
Failure treatment
Keep delivery and payment states visible if atomicity is unavailable.

Ledger, liability, and settlement evidence

ev-ledger → ev-ops

Reconcile instrument supply, claims, transactions, backing, and external settlement.

Contract
event · asynchronous
Controls
  • Authentication and authorisation
  • Integrity and replay protection
  • Correlation and audit evidence
Failure treatment
Stop reopening when ledgers or backing do not reconcile.

Cross-system exception

ev-interoperability → ev-ops

Open a case when two systems disagree or time out.

Contract
event · asynchronous
Controls
  • Authentication and authorisation
  • Integrity and replay protection
  • Correlation and audit evidence
Failure treatment
Keep both states and operator actions immutable.

Authored traces

Two-leg payment-versus-payment exchange

Follow two currency claims from authorised access to matched, conditional final settlement and reconciliation.

  1. Submit the exchange — Two-leg intent created. The participant identifies both currency claims, parties, amounts, and settlement conditions.
  2. Prove authority — Participant and instruction authenticated. The access layer proves who may move each claim.
  3. Apply controls — Instruction eligible. Policy and compliance controls apply to parties, claims, jurisdictions, and arrangement.
  4. Make both legs ready — Currency legs matched and funded. Each ledger or account system records readiness without finalising only one side.
  5. Settle payment versus payment — Both legs final under the arrangement. The control releases one currency leg only with the other.
  6. Record final ownership — Ledger states final. Both settlement records and participant positions now reflect the exchange.
  7. Reconcile claims and settlement — Exchange reconciled. Participants reconcile matched instructions, both ledger outcomes, fees, liquidity, and external evidence.

Stress cases

Only one FX leg is ready

One currency leg lacks liquidity or valid settlement authority.

Last confirmed state
The pair is matched; only one leg is ready.
Settlement
Payment-versus-payment settlement has not completed.
Funds and entries
Neither leg should be treated as final under the illustrated PvP control.
Next owner
FX settlement operations
Safe action
Keep the pair unsettled, resolve liquidity or eligibility, and apply cut-off or cancellation rules.
Evidence required
  • Matched instruction
  • Both ledger states
  • Liquidity position
  • Cut-off and rule
Recovery
  • Fund or correct the missing leg
  • Settle both or expire/cancel under rules
  • Reconcile positions

Cross-ledger bridge stops halfway

Source value is locked or burned but the target action is not confirmed.

Last confirmed state
The source-side condition is recorded; target-side state is uncertain.
Settlement
Cross-system settlement is incomplete.
Funds and entries
The user's usable value may be unavailable on both sides until recovery.
Next owner
Interoperability incident command
Safe action
Freeze the affected path and prove both ledger states before compensation, mint, unlock, or refund.
Evidence required
  • Source proof
  • Target proof
  • Bridge event sequence
  • Operator authority
Recovery
  • Recover target or apply governed compensation
  • Reconcile supply and liabilities
  • Reopen only after two-sided proof

Redemption cannot complete

The token is surrendered but external bank-money payment is delayed or rejected.

Last confirmed state
Redemption request and token state are recorded.
Settlement
External cash settlement is not confirmed.
Funds and entries
The holder's token and issuer liability treatment depends on the governing arrangement.
Next owner
Issuer treasury and redemption operations
Safe action
Do not mark redemption paid; preserve the claim and apply documented retry, reinstatement, or refund treatment.
Evidence required
  • Redemption ID
  • Token burn or lock state
  • Bank payment status
  • Backing and liability records
Recovery
  • Resolve external payment
  • Restore or reissue claim if rules require
  • Reconcile supply, backing, and holder record

Design decisions

What exactly does the holder own or claim?

  • Explicit issuer liability — Makes redemption, insolvency, backing, and reporting questions visible.
  • Technology-only token label — Hides the legal and financial meaning behind a ledger object.

Name issuer, holder claim, settlement asset, governing law, redemption right, backing, and finality before choosing technology.

How should two systems coordinate value?

  • Governed interlink or common platform — Can make two-sided state explicit but concentrates operational, legal, and security dependencies.
  • Uncontrolled representation or bridge — May appear simple but can create duplicate supply and unresolved claims.

Document source and target state, supply conservation, operator authority, timeout, compensation, finality, and incident ownership.

Sources and disclosed synthesis