IMF-支付和結(jié)算的可編程性 Programmability in Payment and Settlement Concepts and Implications 2024

Programmabilityin

PaymentandSettlement

ConceptsandImplications

PreparedbyXavierLavayssièreandNicolasZhangWP/24/177

IMFWorkingPapersdescriberesearchin

progressbytheauthorsandarepublishedtoelicitcommentsandtoencouragedebate.TheviewsexpressedinIMFWorkingPapersare

thoseoftheauthorsanddonotnecessarilyrepresenttheviewsoftheIMF,itsExecutiveBoard,orIMFmanagement.

2024

AUG

NATn

?2024InternationalMonetaryFundWP/24/177

IMFWorkingPaper

InformationTechnologyDepartment

ProgrammabilityinPaymentandSettlement—ConceptsandImplicationsPreparedbyXavierLavayssièreandNicolasZhang1

AuthorizedfordistributionbyHervéTourpeAugust2024

IMFWorkingPapersdescriberesearchinprogressbytheauthorsandarepublishedtoelicit

commentsandtoencouragedebate.TheviewsexpressedinIMFWorkingPapersarethoseoftheauthorsanddonotnecessarilyrepresenttheviewsoftheIMF,itsExecutiveBoard,orIMFmanagement.

ABSTRACT:Programmabilityinpaymentandsettlementhasyettorealizeitspotentialtosupportpolicygoalssuchasefficiency,safety,andinnovation.Thispaperproposesacomprehensiveframeworkforunderstanding

andevaluatingprogrammability.Itexplorestwokeydimensions:externalprogrammaticaccess,whichisthe

abilityforexternalparticipantstoaccessthesystemdataandfunctionswithcode,andinternalprogrammatic

capabilities,theextenttowhichinternalexecutionofprogramsissupportedandguaranteed.Bydeveloping

strategiesbasedonthesedimensions,financialinstitutions,regulators,andrelatedactorscanbetterimprove

resilience,reducecostsandinteroperability,allwhilemanagingassociatedrisks.Theresultinghybridsystems

arecoordinatedeffortsbalancingtheadvantagesofpermissionlessblockchains,suchascomposability,with

regulatoryrequirementsandawiderrangeoftechnologies.Thepaperdescribestheseprogrammaticmodelstoinformandguidethedevelopmentofdigitalfinance,bridgingpolicydiscussionswithtechnicalconsiderations.

RECOMMENDEDCITATION:Lavayssière,Xavier;NicolasZhang(2024).ProgrammabilityinPaymentandSettlement—ConceptsandImplications.WorkingPapersWP/24/177,InternationalMonetaryFund.

JELClassificationNumbers:

E14,L86,F33,G15,O33

Keywords:

Programmability;Tokenization;Automation;Payment;Settlement

Authors’emailaddresses:

XLavayssiere@,

NZhang@

1TheauthorswouldliketothankSonjaDavidovic,ClementBerthou,PaulDesprairies,AndreasVeneris,VeljkoAndrijasevic,Itai

Abraham,GermanVillegas-Bauer,YaizaCabedo,RaunakMittal,AshleyLannquist,ArvinderBharath,VictorBudau,FrankosiligiSolomon,PearlKuebel,andHervéTourpefortheircarefulreviewsandcomments.

WORKINGPAPERS

ProgrammabilityinPaymentandSettlement

ConceptandImplementations

PreparedbyXavierLavayssièreandNicolasZhang

IMFWORKINGPAPERSProgrammabilityinPaymentandSettlement

INTERNATIONALMONETARYFUND4

Contents

Contents 4

Glossary 6

Introduction 8

ExternalProgrammaticAccessinClosedSystems 11

BenefitsofOpeningProgrammability 11

ImplementationChallengesinClosedSystems 12

InternalProgrammaticCapabilitiesofOpenSystems 15

AStandardizedandTransparentEnvironment 15

FromAdvancedProgrammingFeaturestoComposability 18

StrategiesforImprovingProgrammability 19

HybridSystems 21

Trade-offsofEnhancingProgrammability 24

Conclusion 28

Appendi

x 29

References 30

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BOXES

Box1.CategoriesofSmartContracts 18

Box2.ChallengesofProgrammingMoney 27

FIGURES

Figure1.SimplifiedMatrixoftheTwoDimensionsofProgrammability 9

Figure2.ExternalProgramsAccessthePaymentandSettlementSystemthroughAPIs 11

Figure3.RepresentationofaClosedSystemwithOneLedger 13

Figure4.ExternalandInternalCommunicationinPermissionlessBlockchains 16

Figure5.ExampleofaDeFiProtocolCombiningSmartContracts 18

Figure6.HybridModelscanbeEvaluatedalongtheTwoDimensionsofProgrammability 21

Figure7.ExampleofConnectingPermissionedBlockchainswithLegacyInfrastructures 23

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Glossary

ApplicationProgrammingInterface(API):Adigitalinterfaceenablingprogramstointeractwithadigitalplatforminastandardized,secure,andreliablemanner.

AssetSmartContract:Aprogramrunningonablockchaininfrastructurerepresentinganassetdigitally.Itcontainsdataonownership,andoperationfunctions.

Atomicity:Indivisibilityofadigitaloperation.AtomicityisemployedtoguaranteethemutualconditionalityofbothlegsofsettlementmechanismssuchasDvPorPvP.

ConditionalPayment:Apaymentcategorytransmittedwithinstructionstosettleoncespecificconditionsaremet.Suchaconditioncouldbeadelayortheconfirmationoftheotherlegofatrade.

Composability:Thecapacitytoprogrammaticallycombineoperations.Forexample,atokenizeddebtcanserve

ascollateralinotherautomatedoperations.Composabilityreliesonsharedinterfaces,trust-minimization,andconnectedinfrastructures.

Deliveryvs.Payment(DvP):Asettlementmechanismensuringthemutualconditionalityofthetransferofafinancialinstrument,anditscorrespondingpayment.

DistributedSystem:Asoftwaresolutionimplementedovermultipleagents,processes,orcomputers.Properlydesigneddistributedsystemsenhancescalability,availability,andresilienceofdigitalplatforms.

DistributedLedgerTechnology(DLT):AstatemanagementdistributedsysteminspiredbyBitcoin’s

blockchain.DLTsareprimarilyusedinfinancetomaintainasharedledgeracrossvariousentities.

FastPaymentSystem(FPS):Adigitalinfrastructureenablingimmediateornear-real-timetransferandsettlementoffundsbetweenparties.

Ledger:Registeroffinancialassetsownership.Itcandenotedebt,money,orfinancialinstruments.

NativeDigitalAsset:Afinancialassetdirectlyissuedonadigitalplatform.Inthecontextofpermissionless

blockchains,itrefersmorespecificallytotheunderlyingdigitalassetusedtopayforthenetwork’ssecurity(e.g.,BitcoinorEtherontheirrespectiveplatforms).

Open-loopvs.Closed-loop:Anopen-looppaymentsystemisaccessibletodifferentpaymentcompanies(e.g.,cardnetworks),whileaclosed-looppaymentsystemisgenerallylimitedtoonecompany(e.g.,

transportationcardsorvouchercards).

Oracles:Servicesprovidingexternaldatatosmartcontractsonblockchains.Oraclesprovidedata,suchasstockpricesorinterestrates,inadecentralizedorcentralizedmanner.

Partitioning:Processofdividingadatabaseintosmallerlogicalpartitions.Eachpartitioncanbestoredondistinctserverswhilemanagedasaunifieddatabase.

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PaymentandSettlementSystem:arrangements,infrastructuresandschemesthatfacilitatefinancial

transactionsbetweeninstitutions.Theyincludesystemsprovidedbybanks,FintechfirmsandcentralbankssuchasFastPaymentSystemsandFinancialMarketInfrastructures.

Paymentvs.Payment(PvP):Asettlementmechanismensuringthemutualconditioningoftwoparties’payments.Itreducessettlementriskinforeignexchangetransactions.

Permissionlessblockchain:Sharedledgermaintainedbyadistributednetworkwhereanyonecanparticipatetothevalidationaccordingtoconsensusrules.

Primitive:Basicfunctionsofaplatformaccessibletointernal,andexternalprograms.Programsusethemtofetchdataandtriggeractions.

ProgrammableFinancialPlatform:Digitalplatformenablingcode-basedfinancialoperationsthroughinterfaceslikeAPIs,smartcontractsdeployments,orothercode-basedtools.

ProgrammedAsset:Afinancialassetwithcode-definedpropertiesthatmaintainitsintegrityandcontainitsusage.Onablockchain,itusesan“AssetSmartContract.”

SecureElement:Ahardwarecomponentthatguaranteessecurecodeexecutionandsensitivedatastorage.A

secureelementcanconsistofadedicatedchiporasecureenclavewithinamicroprocessor.Secureelementsarecommonlyusedinpaymentcardsandelectronicdevicesforsecurity.

SmartContract:Aprogramrunninginatrust-minimizedmanneronapublicblockchainoraDLTnetwork.Smartcontractscanbeusedtorepresentassets,createatomicoperations,orimplement

DecentralizedFinance(DeFi)protocols.

Tokenization:Processofissuingafinancialassetonashared,programmable,andtrust-minimizedplatform.Thisprocessinvolveslegalandtechnicaloperations.

TrustMinimizingTechnologies(TMT):Technologicaltoolsandmethodsemployedtominimizetheneedfortrustamongpartiesofafinancialtransaction,e.g.,cryptographicsignaturesandsecureelements.

Zero-KnowledgeProof:Acryptographicmethodallowingoneparty(theprover)toproveastatement's

validitytoanother(theverifier)withoutrevealingextrainformation.Theycanbeusedtoensurethatfinancialtransactionshavebeenexecutedaccordingtocodedruleswithoutrevealingtheirdetails.

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Introduction

Programmabilityinpaymentsandsettlementhasyettofullyrealizeitspotentialtosupportpolicygoalssuchasfosteringinnovation,enhancingefficiency,improvingsafetyandreducingfragmentation.2Activeexperimentations,suchasCentralBankDigitalCurrencies(CBDC)andassettokenization,3andevenlive

implementationsareemerginginthefinancialsector.However,technical,regulatory,andfinancialrisks

introducedbynewcapabilitieslikesmartscontractsneedtobeunderstoodandaddressed.Thispaperaimstoexplorethesepointsandidentifyanoptimalbalancebetweenwell-controlledsystemsandmoreinnovative

approaches.

Inthecontextofpaymentsandsettlements,programmabilityisthecapabilitytoperformfinancial

operationsthroughlogicimplementedincomputerprograms.4Theseprogramscanreadbalances,triggerpayments,orinteractwithmoreadvancedfeaturesonbehalfofusers(Figure2).Forillustration,programmableaccesstoaccountinformationattheretaillevelcanenablethecreationofavisualdashboardconsolidating

assetsofanindividualacrossmultiplefinancialinstitutions.Atthewholesalelevel,programscansafelyexecuteoperationssuchasDelivery-vs-Payment(DvP)5settlementmechanisms.

Inpractice,paymentsandsettlementsareexecutedbysystemsoperatedbyfinancialinstitutions,

technologyfirmsandcentralbanks.Thesepaymentandsettlementsystems6provideservicesthatfacilitatefinancialtransactions,servingbothdirectparticipantssuchasbanksandFintechcompanies,and,indirectly,

theirclientssuchasbusinessesandconsumers.Asaresult,thedevelopmentofprogrammabilityinthecontextofpaymentsandsettlementprimarilyaffectsthefinancialindustry,withpotentialbroadereffects.

Anincompleteunderstandingoftheinnovationsthatprogrammabilitycanbringhasoccasionally

resultedinsetbacksandmissedopportunities.Poorprojectandriskmanagementhaveledtothefailureofsomedigitalfinanceinitiatives.7Misunderstandingshavesparkeddebatesoverthebenefitsandrisksof

programmability.8

2Onthepotentialofprogrammabilitytoreducetechnicalandfinancialfragmentation,seeBanquedeFrance(2023).

3Tokenizationistheissuanceoffinancialassetsonaledgerthatpresentscertaincharacteristics,suchasbeingsharedbyseveralparticipantsandprovidingtrust.SeeAdrianetal.(2023),Lavayssière(2023)andAbrahametal.(2024).

4Incomputerscience,aprogramisasetofinstructionswrittenincodethatcanbeexecutedbyacomputer.

5Settlementmechanismensuringthemutualconditioningofthetransferofafinancialinstrumentanditscorrespondingpayment.

6Paymentandsettlementsystemsarearrangements,infrastructuresandschemesthatfacilitatefinancialtransactions.Theyincludecardnetworks,FastPaymentSystems,Real-TimeGrossSettlementSystems,andFinancialMarketInfrastructures.

7AnearlyexampleisprojectTaurus,commissionedbytheLondonStockExchangein1983aimedatunifyingdataenvironmentandexecutionsystemforLondon’ssharesettlementprocedures.Despiteinvestmentofalmost500millionBPD,theprojectultimatelyfailedduetovestedinterests,regulatorychallenges,andmanagementissues(SeeDrummond1996).SeebelowforadescriptionofthemorerecentDLTCHESSproject.

8SeeboxChallengesofProgrammingMoney.

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Thispaperproposesasimpleframeworktounderstandprogrammabilityinthecontextofpaymentandsettlementsystemsthroughtwodimensions.1)How,andthroughwhichprogramorinterfaces,cansystemsbeaccessedandbywhom;2)andwhattasksandfunctionscanthesystemexecuteandsupportandwithwhatguarantees.Weelaborateonthisframeworkthroughoutthepaper,referringtothesedimensionsasexternal

programmaticaccess—theabilityforexternalparticipantstoaccessdataandfunctionsviaprograms—andinternalprogrammaticcapabilities—howasystemsupportsprogramsthatofferexecutionguarantees.Anexampleofsuchinternalprogrammaticcapabilityistheautomaticexecutionofprogramsbasedonother

changesthathappenedwithinthesystem.

Toillustrateprogrammability,digitalsystemscouldbecomparedtomusicboxesandsoundsystemsinthe20thcentury.Amechanicalmusicboxplaysamelodyengravedinitsinternalcylinder.Themelodyis

predefinedandcannotbechanged.Onlythespeedcanbecontrolledbyrotatinganexternalcrank.Incontrast,ananalogicsoundsystemoffersgreaterflexibilityinternallyandexternally.High-qualityaudiotrackscanbe

playedandeasilychangedbyswappingthevinylrecord.Moreover,differentcontrols,speakers,andamplifiersfromvariousmanufacturerscanbeconnectedtoaturntabletoofferawiderangeofexperiences.

Figure1.SimplifiedMatrixoftheTwoDimensionsofProgrammability

Bothclosedandopensystemscanbeadaptedtoachievebetterpolicytrade-offs

Externalprogrammaticaccessandinternalprogrammaticcapabilitiesdefineamatrixtoclassifyprogrammablesystems.Toillustratethismatrix,wedescribetwodesignoptionsatoppositecorners:

programmaticallyclosedsystemswithlowaccessandlowledgercapabilities,suchassomelegacysystems,andopensystemswithmaximumaccessandextensivecapabilities,suchaspermissionlessprogrammable

IMFWORKINGPAPERSProgrammabilityinPaymentandSettlement

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blockchains9(Figure1).Betweentheseextremesliehybridsystemswithvaryingdegreesofprogrammabilitywhichwewillexplorefurther,suchasOpenBankingframeworks,modernFastPaymentSystems(FPS),or

permissionedDistributedLedgerTechnologies(DLT)arrangements.

Thispaperexploresthesedimensionstoproposeastructuredapproachaimedatinformingandguidingthedevelopmentofprogrammablefinance.Thefirstsectiondiscusseshowexternalprogrammaticaccesscan

beadverselyimpactedinclosedpaymentandsettlementsystemsbycharacteristicssuchasnon-standardizedinterfaces,opaqueinternalsystems,anddisjointedservices.Thesecondsectiondescribeshowenhanced

internalprogrammaticcapabilities,throughstandardizedtechnologystacks,distributedcomputing,delegationofservicesandroles,canofferrobustandsophisticatedexecution.Thelastsectionusesthesetwodimensionstoshowhowdifferentstrategiescanbecombined.Byimprovinguponoppositemodelsandmitigatingtheir

respectivedrawbacks,hybridmodelsofprogrammabilitycanpotentiallyachievebetterpolicyandcompliancetrade-offs.

Thisframeworkcontributestothediscussiononprogrammabilityrequirementsforpaymentand

settlementsystems.Theadoptionofcommonconceptsisnecessaryfordesigningandregulatingthenext

generationoffinancialinfrastructures.Asinfrastructuresfortokenization,retail,andwholesaleCBDCsarebeingdeveloped,thispapercontributestobridgepolicydiscussionswithtechnicalconsiderations.Theinsights

providedinthispapersetthefoundationforfurtherresearchanddiscussiononprogrammability,includingtransitionmanagementandriskmitigation.

9Wedefinepermissionlessprogrammableblockchainsasblockchainswhichcanbeaccessedandvalidatedbyanyoneandthatofferadvancedinternalprogrammaticcapabilities.However,thetwopropertiesarenotnecessarilysynonymous,seesectionInternalProgrammaticCapabilitiesofOpenSystems.

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ExternalProgrammaticAccessinClosedSystems

Paymentandsettlementsystemsalreadysupportfinancialoperationsthatcanbetriggeredbycode.Forinstance,thesesystemscanofferfunctionssuchastheabilitytoreadbalanceinquiries,ortosendpayment

instructions.10Wedefineexternalaccessasthecapabilitytoaccessdataandtotriggerfunctionswithinthepaymentandsettlementsystem,byexternalparticipants.11

BenefitsofOpeningProgrammability

ThankstoApplicationProgrammingInterfaces(APIs),functionsofasystemcanbeaccessedbyexternalparticipants.12APIsarecollectionsofproceduresandfunctionsthatenableauthorizedexternalpartiesto

accessdigitalresources.AnAPIgatewayhandlesexternalrequestsandauthorizations(Figure2).Intheanalogyofasoundsystem,externalcomponentssuchasamicrophoneorspeakersexchangeaudiosignalviainputandoutputsockets(orports)oftheturntable.ThesesocketsaretheinterfaceforaudiosignalslikeanAPIisthe

interfaceforprograms.

Figure2.ExternalProgramsAccessthePaymentandSettlementSystemthroughAPIs

ExternalprogramsinteractwiththepaymentandsettlementsystemviatheAPI(ingreen)onbehalfofinstitutionalandretailusers.

Thissimplemodelofprogrammabilityfacilitatesautomation,interoperability,andinnovationacrosssystems.Forexample,merchantscanconnecttheirsystemstofunctionssuchaspayments,rewards,and

additionalfinancialservices.Facilitatingpaymentsisevenacentralpartofsomebusinessmodels,suchas

10Thebasicfunctionsavailablearesometimescalled“primitives.”SeeDeutscheBundesbank(2020)onthenotionoftriggersolutionandLavayssière(2024).Moreadvancedfeaturesareavailableinrestrictedenvironments,seesectionHybridSystems.

11ExternalprogrammaticaccessenableswhatHojoandHatogai(2022)call“externalprogrammingapproaches”andTohetal.

(2004)“client-sideprogrammability”(asopposedto“banksideprogrammability”).

12Whiletheterm"API"isgeneric,itcommonlyreferstoaparticulartypeofinterface:standardwebAPI,whichtypicallyemploys

REST(RepresentationalStateTransfer)architecturalstyles,standardizedURLs(UniformResourceLocator),andHTTPprotocols.

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freelancingplatforms.13Fintechcompaniesbuildtheirentirebusinessmodelsonofferingserviceslayeredon

existingcorebankingfunctions,usingbank-providedAPIs.Asaresult,businesses14andconsumersmaybe

offeredachoicetousenewfinancialservices,andinnovativefeaturesdevelopedontopoflegacysystems.

Moreover,otherpaymentandsettlementsystemscanbothconsume,andofferAPIstofacilitateinteroperabilityacrosspreviouslyisolatedsystems.

Asaresult,advancedfeaturescanbebuiltontopofsimpleinterfaces.Whilepowerful,themodel

describedsofarisrelativelysimple.Itcorrespondstothefirstofthreelevelsofprogrammabilitydefinedin

Lavayssière(2024)as“programmaticallyactionable”:basicoperationscanbetriggeredviaAPIsprovidedbythesystem,suchasapaymentplatform.Despiteitssimplicity,financialserviceproviderscandevelopsome

powerfulandinnovativeservicesbyaggregatingAPIsfromdifferentexternalsystems,offeringadvancedfunctionalitiestoasecondorthirdtierofactors.15

ImplementationChallengesinClosedSystems

Closedpaymentandsettlementsystemshavelimitedoptionsforprogrammabilityastheydonotprovidesuchaccessinterfacesnatively.Thesesystemsconsistofeitherclosed-looppaymentsystemsmanagedbyasingleentityormultipleledgersmanagedbyseparatelegalentities,withcommunicationfacilitatedbyproprietarymessagesandcommoninfrastructures.Accesstodataortheabilitytotriggerpaymentsislimitedduetolegalortechnicalconstraints.Forexample,centralbankstypicallylimitdirectparticipationtotheirpaymentandsettlementinfrastructurestosomecategoriesofregulatedfinancialinstitutions.

Legalconstraintscansignificantlyimpedeexternalaccess.Financialinstitutionsmaylimitaccesstoexternaldevelopersduetoregulatoryconstraints,suchasthepreservationofpersonaldata,tomitigateoperational

risks16or,forstrategiccommercialconsiderations.17Openingaccesstofacilitateintegrationscanraisequestionsofmarketstructureandliabilityasillustratedbythe2024bankruptcyofSynapseFinancialTechnologies.18

13E.g.,Embeddedpaymentsinplatformbusinessmodels(Uber,Mercari,Malt)andlargertechnologyecosystems(Tencent,Antgroup,Apple,Amazon).

14BusinessesmaydirectlyuseAPIstoautomateprocesses,potentiallyreducinghumanerrorsandloweringoperationalcosts,suchasintegrationswithEnterpriseResourcePlanning(ERP)forbetterreconciliationwithinvoicingandaccounting,optimizingB2Bpaymentroutes,andimprovingoncashflowmanagement.

15E.g.,merchantscanofferdirectlyontheirwebsiteBuyNowPayLater(BNPL)totheircustomersviatheintegrationtoapaymentprocessingplatform(e.g.,StripeorAyden)oracomprehensivesolution(e.g.,Shopify)thatwillsolicitaFintechcompany(e.g.,KlarnaorRatePay)orBankingasaservicesolution(BAAS,e.g.,BBVAorFinastra)toofferaloan.

16N.B.,eachbankhasaspecificriskprofilethatdeterminesitscybersecurityposture.

17E.g.,regulatorycaptureandsecurityconcernsoftenleadtolimitedthird-partyaccessandoperatinghours.SeePetry(2021).

18SynapseFinancialTechnologiesisaUnitedStates-basedcompanyproviding“BankingasaService”tootherFintechfirms.Itsfilingforbankruptcyin2024resultedinuncertaintyregardingmillionsofdollarsdepositedbycustomers.Thecourtcaseshighlight

thefragilityoftherelationshipsbetweenSynapse,itsservicingbankandFintechclients.

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Restrictionsareoftenreflectedwithinthetermsandconditionsofcontractsbetweenparticipantsorestablishedbyspecificregulations.19

Interfacequalityandlackofstandardizationpresentmajoroperationalchallenges.Theperformanceofapplicationsdependsonthequalityofinterfacesandcanfallshortofmeetingexpectationsregardinglatency,failurerate,andavailability.Moreover,thelackofstandardizationacrosssystemsleadstohighintegration

costs.Forexample,ifseveralbanksofferanopenAPItoaccesstheirserviceswithslightdifferencesintermsofformatandresponsetime,uniformservicedeliveryacrossbanksbecomesimpracticalandcostly.

Theinternalarchitectureofclosedsystemsisoftencomplexandnotconducivetoenablingnew

programmaticcapabilities.Overtime,thesesystemshaveevolvedbyaddingandsometimesduplicatingdatabasesorothercomponents,leadingtoacomplexandfragmentedstructurethatrequirescareful

reconciliation.Thecomplexityarisesfrommultiplefactors,includinglegacycomponents,disparate

technologies,andinconsistentinterfaces(Figure3).Enhancingprogrammabilityinsuchlegacyinfrastructuresischallengingandoftenincurshighcostsandextendedtimelines,particularlywhenmultipleentitiesareinvolved,suchasinthecaseofmultilateralplatformsandFinancialMarketInfrastructures(FMIs).

Figure3.RepresentationofaClosedSystemwithOneLedger

TheorangeshapesillustratethedifferentinternalAPIsthatcanbeinvolvedwhentriggeringservices.

Regulatoryeffortshavebeeninsufficientinaddressingthesechallenges.Despitethepushtowards

regulatoryframeworkssuchasOpenbanking20toimproveexternalprogrammaticaccess,theseeffortshaveremainedlimitedinscopeandeffectiveness.21Thelackofstrongtechnicalandregulatorystandards,andthe

19Foranexampleofrestrictingconditionstoaccessa