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.