Intro

When thinking about security, it is good to start with a specific threat model. Our threat model is the following:
We assume that a thriving ecosystem of Cosmos SDK modules that are easy to compose into a blockchain application will contain faulty or malicious modules.
The Cosmos SDK is designed to address this threat by being the foundation of an object capability system.
The structural properties of object capability systems favor modularity in code design and ensure reliable encapsulation in code implementation. These structural properties facilitate the analysis of some security properties of an object-capability program or operating system. Some of these — in particular, information flow properties — can be analyzed at the level of object references and connectivity, independent of any knowledge or analysis of the code that determines the behavior of the objects. As a consequence, these security properties can be established and maintained in the presence of new objects that contain unknown and possibly malicious code. These structural properties stem from the two rules governing access to existing objects:
  1. An object A can send a message to B only if object A holds a reference to B.
  2. An object A can obtain a reference to C only if object A receives a message containing a reference to C. As a consequence of these two rules, an object can obtain a reference to another object only through a preexisting chain of references. In short, “Only connectivity begets connectivity.”
For an introduction to object-capabilities, see this Wikipedia article.

Ocaps in practice

The idea is to only reveal what is necessary to get the work done. For example, the following code snippet violates the object capabilities principle:
type AppAccount struct {...
}
    account := &AppAccount{
    Address: pub.Address(),
    Coins: sdk.Coins{
    sdk.NewInt64Coin("ATM", 100)
},
}
    sumValue := externalModule.ComputeSumValue(account)
The method ComputeSumValue implies a pure function, yet the implied capability of accepting a pointer value is the capability to modify that value. The preferred method signature should take a copy instead.
sumValue := externalModule.ComputeSumValue(*account)
In the Cosmos SDK, you can see the application of this principle in simapp.
/go:build app_v1

package simapp

import (
    
	"encoding/json"
    "fmt"
    "io"
    "maps"
    "os"

	abci "github.com/cometbft/cometbft/abci/types"
	dbm "github.com/cosmos/cosmos-db"
    "github.com/cosmos/gogoproto/proto"
    "github.com/spf13/cast"

	autocliv1 "cosmossdk.io/api/cosmos/autocli/v1"
	reflectionv1 "cosmossdk.io/api/cosmos/reflection/v1"
    "cosmossdk.io/client/v2/autocli"
	clienthelpers "cosmossdk.io/client/v2/helpers"
    "cosmossdk.io/core/appmodule"
    "cosmossdk.io/log"
	storetypes "cosmossdk.io/store/types"
    "cosmossdk.io/x/circuit"
	circuitkeeper "cosmossdk.io/x/circuit/keeper"
	circuittypes "cosmossdk.io/x/circuit/types"
    "cosmossdk.io/x/evidence"
	evidencekeeper "cosmossdk.io/x/evidence/keeper"
	evidencetypes "cosmossdk.io/x/evidence/types"
    "cosmossdk.io/x/feegrant"
	feegrantkeeper "cosmossdk.io/x/feegrant/keeper"
	feegrantmodule "cosmossdk.io/x/feegrant/module"
    "cosmossdk.io/x/nft"
	nftkeeper "cosmossdk.io/x/nft/keeper"
	nftmodule "cosmossdk.io/x/nft/module"
    "cosmossdk.io/x/tx/signing"
    "cosmossdk.io/x/upgrade"
	upgradekeeper "cosmossdk.io/x/upgrade/keeper"
	upgradetypes "cosmossdk.io/x/upgrade/types"
    "github.com/cosmos/cosmos-sdk/baseapp"
    "github.com/cosmos/cosmos-sdk/client"
    "github.com/cosmos/cosmos-sdk/client/flags"
    "github.com/cosmos/cosmos-sdk/client/grpc/cmtservice"
	nodeservice "github.com/cosmos/cosmos-sdk/client/grpc/node"
    "github.com/cosmos/cosmos-sdk/codec"
    "github.com/cosmos/cosmos-sdk/codec/address"
    "github.com/cosmos/cosmos-sdk/codec/types"
    "github.com/cosmos/cosmos-sdk/runtime"
	runtimeservices "github.com/cosmos/cosmos-sdk/runtime/services"
    "github.com/cosmos/cosmos-sdk/server"
    "github.com/cosmos/cosmos-sdk/server/api"
    "github.com/cosmos/cosmos-sdk/server/config"
	servertypes "github.com/cosmos/cosmos-sdk/server/types"
    "github.com/cosmos/cosmos-sdk/std"
	testdata_pulsar "github.com/cosmos/cosmos-sdk/testutil/testdata/testpb"
	sdk "github.com/cosmos/cosmos-sdk/types"
    "github.com/cosmos/cosmos-sdk/types/module"
    "github.com/cosmos/cosmos-sdk/types/msgservice"
	sigtypes "github.com/cosmos/cosmos-sdk/types/tx/signing"
    "github.com/cosmos/cosmos-sdk/version"
    "github.com/cosmos/cosmos-sdk/x/auth"
    "github.com/cosmos/cosmos-sdk/x/auth/ante"
	authcodec "github.com/cosmos/cosmos-sdk/x/auth/codec"
	authkeeper "github.com/cosmos/cosmos-sdk/x/auth/keeper"
    "github.com/cosmos/cosmos-sdk/x/auth/posthandler"
	authsims "github.com/cosmos/cosmos-sdk/x/auth/simulation"
    "github.com/cosmos/cosmos-sdk/x/auth/tx"
	authtx "github.com/cosmos/cosmos-sdk/x/auth/tx"
	txmodule "github.com/cosmos/cosmos-sdk/x/auth/tx/config"
	authtypes "github.com/cosmos/cosmos-sdk/x/auth/types"
    "github.com/cosmos/cosmos-sdk/x/auth/vesting"
	vestingtypes "github.com/cosmos/cosmos-sdk/x/auth/vesting/types"
    "github.com/cosmos/cosmos-sdk/x/authz"
	authzkeeper "github.com/cosmos/cosmos-sdk/x/authz/keeper"
	authzmodule "github.com/cosmos/cosmos-sdk/x/authz/module"
    "github.com/cosmos/cosmos-sdk/x/bank"
	bankkeeper "github.com/cosmos/cosmos-sdk/x/bank/keeper"
	banktypes "github.com/cosmos/cosmos-sdk/x/bank/types"
	consensus "github.com/cosmos/cosmos-sdk/x/consensus"
	consensusparamkeeper "github.com/cosmos/cosmos-sdk/x/consensus/keeper"
	consensusparamtypes "github.com/cosmos/cosmos-sdk/x/consensus/types"
	distr "github.com/cosmos/cosmos-sdk/x/distribution"
	distrkeeper "github.com/cosmos/cosmos-sdk/x/distribution/keeper"
	distrtypes "github.com/cosmos/cosmos-sdk/x/distribution/types"
    "github.com/cosmos/cosmos-sdk/x/epochs"
	epochskeeper "github.com/cosmos/cosmos-sdk/x/epochs/keeper"
	epochstypes "github.com/cosmos/cosmos-sdk/x/epochs/types"
    "github.com/cosmos/cosmos-sdk/x/genutil"
	genutiltypes "github.com/cosmos/cosmos-sdk/x/genutil/types"
    "github.com/cosmos/cosmos-sdk/x/gov"
	govclient "github.com/cosmos/cosmos-sdk/x/gov/client"
	govkeeper "github.com/cosmos/cosmos-sdk/x/gov/keeper"
	govtypes "github.com/cosmos/cosmos-sdk/x/gov/types"
	govv1beta1 "github.com/cosmos/cosmos-sdk/x/gov/types/v1beta1"
    "github.com/cosmos/cosmos-sdk/x/group"
	groupkeeper "github.com/cosmos/cosmos-sdk/x/group/keeper"
	groupmodule "github.com/cosmos/cosmos-sdk/x/group/module"
    "github.com/cosmos/cosmos-sdk/x/mint"
	mintkeeper "github.com/cosmos/cosmos-sdk/x/mint/keeper"
	minttypes "github.com/cosmos/cosmos-sdk/x/mint/types"
    "github.com/cosmos/cosmos-sdk/x/protocolpool"
	protocolpoolkeeper "github.com/cosmos/cosmos-sdk/x/protocolpool/keeper"
	protocolpooltypes "github.com/cosmos/cosmos-sdk/x/protocolpool/types"
    "github.com/cosmos/cosmos-sdk/x/slashing"
	slashingkeeper "github.com/cosmos/cosmos-sdk/x/slashing/keeper"
	slashingtypes "github.com/cosmos/cosmos-sdk/x/slashing/types"
    "github.com/cosmos/cosmos-sdk/x/staking"
	stakingkeeper "github.com/cosmos/cosmos-sdk/x/staking/keeper"
	stakingtypes "github.com/cosmos/cosmos-sdk/x/staking/types"
)

const appName = "SimApp"

var (
	/ DefaultNodeHome default home directories for the application daemon
	DefaultNodeHome string

	/ module account permissions
	maccPerms = map[string][]string{
    authtypes.FeeCollectorName:                  nil,
		distrtypes.ModuleName:                       nil,
		minttypes.ModuleName:                        {
    authtypes.Minter
},
		stakingtypes.BondedPoolName:                 {
    authtypes.Burner, authtypes.Staking
},
		stakingtypes.NotBondedPoolName:              {
    authtypes.Burner, authtypes.Staking
},
		govtypes.ModuleName:                         {
    authtypes.Burner
},
		nft.ModuleName:                              nil,
		protocolpooltypes.ModuleName:                nil,
		protocolpooltypes.ProtocolPoolEscrowAccount: nil
}
)

var (
	_ runtime.AppI            = (*SimApp)(nil)
	_ servertypes.Application = (*SimApp)(nil)
)

/ SimApp extends an ABCI application, but with most of its parameters exported.
/ They are exported for convenience in creating helper functions, as object
/ capabilities aren't needed for testing.
type SimApp struct {
	*baseapp.BaseApp
	legacyAmino       *codec.LegacyAmino
	appCodec          codec.Codec
	txConfig          client.TxConfig
	interfaceRegistry types.InterfaceRegistry

	/ keys to access the substores
	keys map[string]*storetypes.KVStoreKey

	/ essential keepers
	AccountKeeper         authkeeper.AccountKeeper
	BankKeeper            bankkeeper.BaseKeeper
	StakingKeeper         *stakingkeeper.Keeper
	SlashingKeeper        slashingkeeper.Keeper
	MintKeeper            mintkeeper.Keeper
	DistrKeeper           distrkeeper.Keeper
	GovKeeper             govkeeper.Keeper
	UpgradeKeeper         *upgradekeeper.Keeper
	EvidenceKeeper        evidencekeeper.Keeper
	ConsensusParamsKeeper consensusparamkeeper.Keeper
	CircuitKeeper         circuitkeeper.Keeper

	/ supplementary keepers
	FeeGrantKeeper     feegrantkeeper.Keeper
	GroupKeeper        groupkeeper.Keeper
	AuthzKeeper        authzkeeper.Keeper
	NFTKeeper          nftkeeper.Keeper
	EpochsKeeper       epochskeeper.Keeper
	ProtocolPoolKeeper protocolpoolkeeper.Keeper

	/ the module manager
	ModuleManager      *module.Manager
	BasicModuleManager module.BasicManager

	/ simulation manager
	sm *module.SimulationManager

	/ module configurator
	configurator module.Configurator
}

func init() {
    var err error
	DefaultNodeHome, err = clienthelpers.GetNodeHomeDirectory(".simapp")
    if err != nil {
    panic(err)
}
}

/ NewSimApp returns a reference to an initialized SimApp.
func NewSimApp(
	logger log.Logger,
	db dbm.DB,
	traceStore io.Writer,
	loadLatest bool,
	appOpts servertypes.AppOptions,
	baseAppOptions ...func(*baseapp.BaseApp),
) *SimApp {
    interfaceRegistry, _ := types.NewInterfaceRegistryWithOptions(types.InterfaceRegistryOptions{
    ProtoFiles: proto.HybridResolver,
    SigningOptions: signing.Options{
    AddressCodec: address.Bech32Codec{
    Bech32Prefix: sdk.GetConfig().GetBech32AccountAddrPrefix(),
},
    ValidatorAddressCodec: address.Bech32Codec{
    Bech32Prefix: sdk.GetConfig().GetBech32ValidatorAddrPrefix(),
},
},
})
    appCodec := codec.NewProtoCodec(interfaceRegistry)
    legacyAmino := codec.NewLegacyAmino()
    txConfig := tx.NewTxConfig(appCodec, tx.DefaultSignModes)
    if err := interfaceRegistry.SigningContext().Validate(); err != nil {
    panic(err)
}

std.RegisterLegacyAminoCodec(legacyAmino)

std.RegisterInterfaces(interfaceRegistry)

	/ Below we could construct and set an application specific mempool and
	/ ABCI 1.0 PrepareProposal and ProcessProposal handlers. These defaults are
	/ already set in the SDK's BaseApp, this shows an example of how to override
	/ them.
	/
	/ Example:
	/
	/ bApp := baseapp.NewBaseApp(...)
	/ nonceMempool := mempool.NewSenderNonceMempool()
	/ abciPropHandler := NewDefaultProposalHandler(nonceMempool, bApp)
	/
	/ bApp.SetMempool(nonceMempool)
	/ bApp.SetPrepareProposal(abciPropHandler.PrepareProposalHandler())
	/ bApp.SetProcessProposal(abciPropHandler.ProcessProposalHandler())
	/
	/ Alternatively, you can construct BaseApp options, append those to
	/ baseAppOptions and pass them to NewBaseApp.
	/
	/ Example:
	/
	/ prepareOpt = func(app *baseapp.BaseApp) {
	/ 	abciPropHandler := baseapp.NewDefaultProposalHandler(nonceMempool, app)
	/ 	app.SetPrepareProposal(abciPropHandler.PrepareProposalHandler())
	/
}
	/ baseAppOptions = append(baseAppOptions, prepareOpt)

	/ create and set dummy vote extension handler
    voteExtOp := func(bApp *baseapp.BaseApp) {
    voteExtHandler := NewVoteExtensionHandler()

voteExtHandler.SetHandlers(bApp)
}

baseAppOptions = append(baseAppOptions, voteExtOp, baseapp.SetOptimisticExecution())
    bApp := baseapp.NewBaseApp(appName, logger, db, txConfig.TxDecoder(), baseAppOptions...)

bApp.SetCommitMultiStoreTracer(traceStore)

bApp.SetVersion(version.Version)

bApp.SetInterfaceRegistry(interfaceRegistry)

bApp.SetTxEncoder(txConfig.TxEncoder())
    keys := storetypes.NewKVStoreKeys(
		authtypes.StoreKey,
		banktypes.StoreKey,
		stakingtypes.StoreKey,
		minttypes.StoreKey,
		distrtypes.StoreKey,
		slashingtypes.StoreKey,
		govtypes.StoreKey,
		consensusparamtypes.StoreKey,
		upgradetypes.StoreKey,
		feegrant.StoreKey,
		evidencetypes.StoreKey,
		circuittypes.StoreKey,
		authzkeeper.StoreKey,
		nftkeeper.StoreKey,
		group.StoreKey,
		epochstypes.StoreKey,
		protocolpooltypes.StoreKey,
	)

	/ register streaming services
    if err := bApp.RegisterStreamingServices(appOpts, keys); err != nil {
    panic(err)
}
    app := &SimApp{
    BaseApp:           bApp,
		legacyAmino:       legacyAmino,
		appCodec:          appCodec,
		txConfig:          txConfig,
		interfaceRegistry: interfaceRegistry,
		keys:              keys,
}

	/ set the BaseApp's parameter store
	app.ConsensusParamsKeeper = consensusparamkeeper.NewKeeper(
		appCodec,
		runtime.NewKVStoreService(keys[consensusparamtypes.StoreKey]),
		authtypes.NewModuleAddress(govtypes.ModuleName).String(),
		runtime.EventService{
},
	)

bApp.SetParamStore(app.ConsensusParamsKeeper.ParamsStore)

	/ add keepers
	app.AccountKeeper = authkeeper.NewAccountKeeper(
		appCodec,
		runtime.NewKVStoreService(keys[authtypes.StoreKey]),
		authtypes.ProtoBaseAccount,
		maccPerms,
		authcodec.NewBech32Codec(sdk.Bech32MainPrefix),
		sdk.Bech32MainPrefix,
		authtypes.NewModuleAddress(govtypes.ModuleName).String(),
	)

app.BankKeeper = bankkeeper.NewBaseKeeper(
		appCodec,
		runtime.NewKVStoreService(keys[banktypes.StoreKey]),
		app.AccountKeeper,
		BlockedAddresses(),
		authtypes.NewModuleAddress(govtypes.ModuleName).String(),
		logger,
	)

	/ optional: enable sign mode textual by overwriting the default tx config (after setting the bank keeper)
    enabledSignModes := append(tx.DefaultSignModes, sigtypes.SignMode_SIGN_MODE_TEXTUAL)
    txConfigOpts := tx.ConfigOptions{
    EnabledSignModes:           enabledSignModes,
    TextualCoinMetadataQueryFn: txmodule.NewBankKeeperCoinMetadataQueryFn(app.BankKeeper),
}

txConfig, err := tx.NewTxConfigWithOptions(
		appCodec,
		txConfigOpts,
	)
    if err != nil {
    panic(err)
}

app.txConfig = txConfig

	app.StakingKeeper = stakingkeeper.NewKeeper(
		appCodec,
		runtime.NewKVStoreService(keys[stakingtypes.StoreKey]),
		app.AccountKeeper,
		app.BankKeeper,
		authtypes.NewModuleAddress(govtypes.ModuleName).String(),
		authcodec.NewBech32Codec(sdk.Bech32PrefixValAddr),
		authcodec.NewBech32Codec(sdk.Bech32PrefixConsAddr),
	)

app.MintKeeper = mintkeeper.NewKeeper(
		appCodec,
		runtime.NewKVStoreService(keys[minttypes.StoreKey]),
		app.StakingKeeper,
		app.AccountKeeper,
		app.BankKeeper,
		authtypes.FeeCollectorName,
		authtypes.NewModuleAddress(govtypes.ModuleName).String(),
	)

app.ProtocolPoolKeeper = protocolpoolkeeper.NewKeeper(
		appCodec,
		runtime.NewKVStoreService(keys[protocolpooltypes.StoreKey]),
		app.AccountKeeper,
		app.BankKeeper,
		authtypes.NewModuleAddress(govtypes.ModuleName).String(),
	)

app.DistrKeeper = distrkeeper.NewKeeper(
		appCodec,
		runtime.NewKVStoreService(keys[distrtypes.StoreKey]),
		app.AccountKeeper,
		app.BankKeeper,
		app.StakingKeeper,
		authtypes.FeeCollectorName,
		authtypes.NewModuleAddress(govtypes.ModuleName).String(),
		distrkeeper.WithExternalCommunityPool(app.ProtocolPoolKeeper),
	)

app.SlashingKeeper = slashingkeeper.NewKeeper(
		appCodec,
		legacyAmino,
		runtime.NewKVStoreService(keys[slashingtypes.StoreKey]),
		app.StakingKeeper,
		authtypes.NewModuleAddress(govtypes.ModuleName).String(),
	)

app.FeeGrantKeeper = feegrantkeeper.NewKeeper(
		appCodec,
		runtime.NewKVStoreService(keys[feegrant.StoreKey]),
		app.AccountKeeper,
	)

	/ register the staking hooks
	/ NOTE: stakingKeeper above is passed by reference, so that it will contain these hooks
	app.StakingKeeper.SetHooks(
		stakingtypes.NewMultiStakingHooks(
			app.DistrKeeper.Hooks(),
			app.SlashingKeeper.Hooks(),
		),
	)

app.CircuitKeeper = circuitkeeper.NewKeeper(
		appCodec,
		runtime.NewKVStoreService(keys[circuittypes.StoreKey]),
		authtypes.NewModuleAddress(govtypes.ModuleName).String(),
		app.AccountKeeper.AddressCodec(),
	)

app.BaseApp.SetCircuitBreaker(&app.CircuitKeeper)

app.AuthzKeeper = authzkeeper.NewKeeper(
		runtime.NewKVStoreService(keys[authzkeeper.StoreKey]),
		appCodec,
		app.MsgServiceRouter(),
		app.AccountKeeper,
	)
    groupConfig := group.DefaultConfig()
	/*
		Example of setting group params:
		groupConfig.MaxMetadataLen = 1000
	*/
	app.GroupKeeper = groupkeeper.NewKeeper(
		keys[group.StoreKey],
		appCodec,
		app.MsgServiceRouter(),
		app.AccountKeeper,
		groupConfig,
	)

	/ get skipUpgradeHeights from the app options
    skipUpgradeHeights := map[int64]bool{
}
    for _, h := range cast.ToIntSlice(appOpts.Get(server.FlagUnsafeSkipUpgrades)) {
    skipUpgradeHeights[int64(h)] = true
}
    homePath := cast.ToString(appOpts.Get(flags.FlagHome))
	/ set the governance module account as the authority for conducting upgrades
	app.UpgradeKeeper = upgradekeeper.NewKeeper(
		skipUpgradeHeights,
		runtime.NewKVStoreService(keys[upgradetypes.StoreKey]),
		appCodec,
		homePath,
		app.BaseApp,
		authtypes.NewModuleAddress(govtypes.ModuleName).String(),
	)

	/ Register the proposal types
	/ Deprecated: Avoid adding new handlers, instead use the new proposal flow
	/ by granting the governance module the right to execute the message.
	/ See: https://docs.cosmos.network/main/modules/gov#proposal-messages
    govRouter := govv1beta1.NewRouter()

govRouter.AddRoute(govtypes.RouterKey, govv1beta1.ProposalHandler)
    govConfig := govtypes.DefaultConfig()
	/*
		Example of setting gov params:
		govConfig.MaxMetadataLen = 10000
	*/
    govKeeper := govkeeper.NewKeeper(
		appCodec,
		runtime.NewKVStoreService(keys[govtypes.StoreKey]),
		app.AccountKeeper,
		app.BankKeeper,
		app.StakingKeeper,
		app.DistrKeeper,
		app.MsgServiceRouter(),
		govConfig,
		authtypes.NewModuleAddress(govtypes.ModuleName).String(),
	)

	/ Set legacy router for backwards compatibility with gov v1beta1
	govKeeper.SetLegacyRouter(govRouter)

app.GovKeeper = *govKeeper.SetHooks(
		govtypes.NewMultiGovHooks(
		/ register the governance hooks
		),
	)

app.NFTKeeper = nftkeeper.NewKeeper(
		runtime.NewKVStoreService(keys[nftkeeper.StoreKey]),
		appCodec,
		app.AccountKeeper,
		app.BankKeeper,
	)

	/ create evidence keeper with router
    evidenceKeeper := evidencekeeper.NewKeeper(
		appCodec,
		runtime.NewKVStoreService(keys[evidencetypes.StoreKey]),
		app.StakingKeeper,
		app.SlashingKeeper,
		app.AccountKeeper.AddressCodec(),
		runtime.ProvideCometInfoService(),
	)
	/ If evidence needs to be handled for the app, set routes in router here and seal
	app.EvidenceKeeper = *evidenceKeeper

	app.EpochsKeeper = epochskeeper.NewKeeper(
		runtime.NewKVStoreService(keys[epochstypes.StoreKey]),
		appCodec,
	)

app.EpochsKeeper.SetHooks(
		epochstypes.NewMultiEpochHooks(
		/ insert epoch hooks receivers here
		),
	)

	/****  Module Options ****/

	/ NOTE: Any module instantiated in the module manager that is later modified
	/ must be passed by reference here.
	app.ModuleManager = module.NewManager(
		genutil.NewAppModule(
			app.AccountKeeper, app.StakingKeeper, app,
			txConfig,
		),
		auth.NewAppModule(appCodec, app.AccountKeeper, authsims.RandomGenesisAccounts, nil),
		vesting.NewAppModule(app.AccountKeeper, app.BankKeeper),
		bank.NewAppModule(appCodec, app.BankKeeper, app.AccountKeeper, nil),
		feegrantmodule.NewAppModule(appCodec, app.AccountKeeper, app.BankKeeper, app.FeeGrantKeeper, app.interfaceRegistry),
		gov.NewAppModule(appCodec, &app.GovKeeper, app.AccountKeeper, app.BankKeeper, nil),
		mint.NewAppModule(appCodec, app.MintKeeper, app.AccountKeeper, nil, nil),
		slashing.NewAppModule(appCodec, app.SlashingKeeper, app.AccountKeeper, app.BankKeeper, app.StakingKeeper, nil, app.interfaceRegistry),
		distr.NewAppModule(appCodec, app.DistrKeeper, app.AccountKeeper, app.BankKeeper, app.StakingKeeper, nil),
		staking.NewAppModule(appCodec, app.StakingKeeper, app.AccountKeeper, app.BankKeeper, nil),
		upgrade.NewAppModule(app.UpgradeKeeper, app.AccountKeeper.AddressCodec()),
		evidence.NewAppModule(app.EvidenceKeeper),
		authzmodule.NewAppModule(appCodec, app.AuthzKeeper, app.AccountKeeper, app.BankKeeper, app.interfaceRegistry),
		groupmodule.NewAppModule(appCodec, app.GroupKeeper, app.AccountKeeper, app.BankKeeper, app.interfaceRegistry),
		nftmodule.NewAppModule(appCodec, app.NFTKeeper, app.AccountKeeper, app.BankKeeper, app.interfaceRegistry),
		consensus.NewAppModule(appCodec, app.ConsensusParamsKeeper),
		circuit.NewAppModule(appCodec, app.CircuitKeeper),
		epochs.NewAppModule(appCodec, app.EpochsKeeper),
		protocolpool.NewAppModule(appCodec, app.ProtocolPoolKeeper, app.AccountKeeper, app.BankKeeper),
	)

	/ BasicModuleManager defines the module BasicManager is in charge of setting up basic,
	/ non-dependant module elements, such as codec registration and genesis verification.
	/ By default it is composed of all the module from the module manager.
	/ Additionally, app module basics can be overwritten by passing them as argument.
	app.BasicModuleManager = module.NewBasicManagerFromManager(
		app.ModuleManager,
		map[string]module.AppModuleBasic{
    genutiltypes.ModuleName: genutil.NewAppModuleBasic(genutiltypes.DefaultMessageValidator),
			govtypes.ModuleName: gov.NewAppModuleBasic(
				[]govclient.ProposalHandler{
},
			),
})

app.BasicModuleManager.RegisterLegacyAminoCodec(legacyAmino)

app.BasicModuleManager.RegisterInterfaces(interfaceRegistry)

	/ NOTE: upgrade module is required to be prioritized
	app.ModuleManager.SetOrderPreBlockers(
		upgradetypes.ModuleName,
		authtypes.ModuleName,
	)
	/ During begin block slashing happens after distr.BeginBlocker so that
	/ there is nothing left over in the validator fee pool, so as to keep the
	/ CanWithdrawInvariant invariant.
	/ NOTE: staking module is required if HistoricalEntries param > 0
	app.ModuleManager.SetOrderBeginBlockers(
		minttypes.ModuleName,
		distrtypes.ModuleName,
		protocolpooltypes.ModuleName,
		slashingtypes.ModuleName,
		evidencetypes.ModuleName,
		stakingtypes.ModuleName,
		genutiltypes.ModuleName,
		authz.ModuleName,
		epochstypes.ModuleName,
	)

app.ModuleManager.SetOrderEndBlockers(
		govtypes.ModuleName,
		stakingtypes.ModuleName,
		genutiltypes.ModuleName,
		feegrant.ModuleName,
		group.ModuleName,
		protocolpooltypes.ModuleName,
	)

	/ NOTE: The genutils module must occur after staking so that pools are
	/ properly initialized with tokens from genesis accounts.
	/ NOTE: The genutils module must also occur after auth so that it can access the params from auth.
    genesisModuleOrder := []string{
    authtypes.ModuleName,
		banktypes.ModuleName,
		distrtypes.ModuleName,
		stakingtypes.ModuleName,
		slashingtypes.ModuleName,
		govtypes.ModuleName,
		minttypes.ModuleName,
		genutiltypes.ModuleName,
		evidencetypes.ModuleName,
		authz.ModuleName,
		feegrant.ModuleName,
		nft.ModuleName,
		group.ModuleName,
		upgradetypes.ModuleName,
		vestingtypes.ModuleName,
		consensusparamtypes.ModuleName,
		circuittypes.ModuleName,
		epochstypes.ModuleName,
		protocolpooltypes.ModuleName,
}
    exportModuleOrder := []string{
    consensusparamtypes.ModuleName,
		authtypes.ModuleName,
		protocolpooltypes.ModuleName, / Must be exported before bank
		banktypes.ModuleName,
		distrtypes.ModuleName,
		stakingtypes.ModuleName,
		slashingtypes.ModuleName,
		govtypes.ModuleName,
		minttypes.ModuleName,
		genutiltypes.ModuleName,
		evidencetypes.ModuleName,
		authz.ModuleName,
		feegrant.ModuleName,
		nft.ModuleName,
		group.ModuleName,
		upgradetypes.ModuleName,
		vestingtypes.ModuleName,
		circuittypes.ModuleName,
		epochstypes.ModuleName,
}

app.ModuleManager.SetOrderInitGenesis(genesisModuleOrder...)

app.ModuleManager.SetOrderExportGenesis(exportModuleOrder...)

	/ Uncomment if you want to set a custom migration order here.
	/ app.ModuleManager.SetOrderMigrations(custom order)

app.configurator = module.NewConfigurator(app.appCodec, app.MsgServiceRouter(), app.GRPCQueryRouter())

err = app.ModuleManager.RegisterServices(app.configurator)
    if err != nil {
    panic(err)
}

	/ RegisterUpgradeHandlers is used for registering any on-chain upgrades.
	/ Make sure it's called after `app.ModuleManager` and `app.configurator` are set.
	app.RegisterUpgradeHandlers()

autocliv1.RegisterQueryServer(app.GRPCQueryRouter(), runtimeservices.NewAutoCLIQueryService(app.ModuleManager.Modules))

reflectionSvc, err := runtimeservices.NewReflectionService()
    if err != nil {
    panic(err)
}

reflectionv1.RegisterReflectionServiceServer(app.GRPCQueryRouter(), reflectionSvc)

	/ add test gRPC service for testing gRPC queries in isolation
	testdata_pulsar.RegisterQueryServer(app.GRPCQueryRouter(), testdata_pulsar.QueryImpl{
})

	/ create the simulation manager and define the order of the modules for deterministic simulations
	/
	/ NOTE: this is not required apps that don't use the simulator for fuzz testing
	/ transactions
    overrideModules := map[string]module.AppModuleSimulation{
    authtypes.ModuleName: auth.NewAppModule(app.appCodec, app.AccountKeeper, authsims.RandomGenesisAccounts, nil),
}

app.sm = module.NewSimulationManagerFromAppModules(app.ModuleManager.Modules, overrideModules)

app.sm.RegisterStoreDecoders()

	/ initialize stores
	app.MountKVStores(keys)

	/ initialize BaseApp
	app.SetInitChainer(app.InitChainer)

app.SetPreBlocker(app.PreBlocker)

app.SetBeginBlocker(app.BeginBlocker)

app.SetEndBlocker(app.EndBlocker)

app.setAnteHandler(txConfig)

	/ In v0.46, the SDK introduces _postHandlers_. PostHandlers are like
	/ antehandlers, but are run _after_ the `runMsgs` execution. They are also
	/ defined as a chain, and have the same signature as antehandlers.
	/
	/ In baseapp, postHandlers are run in the same store branch as `runMsgs`,
	/ meaning that both `runMsgs` and `postHandler` state will be committed if
	/ both are successful, and both will be reverted if any of the two fails.
	/
	/ The SDK exposes a default postHandlers chain
	/
	/ Please note that changing any of the anteHandler or postHandler chain is
	/ likely to be a state-machine breaking change, which needs a coordinated
	/ upgrade.
	app.setPostHandler()

	/ At startup, after all modules have been registered, check that all prot
	/ annotations are correct.
	protoFiles, err := proto.MergedRegistry()
    if err != nil {
    panic(err)
}

err = msgservice.ValidateProtoAnnotations(protoFiles)
    if err != nil {
		/ Once we switch to using protoreflect-based antehandlers, we might
		/ want to panic here instead of logging a warning.
		fmt.Fprintln(os.Stderr, err.Error())
}
    if loadLatest {
    if err := app.LoadLatestVersion(); err != nil {
    panic(fmt.Errorf("error loading last version: %w", err))
}
	
}

return app
}

func (app *SimApp)

setAnteHandler(txConfig client.TxConfig) {
    anteHandler, err := NewAnteHandler(
		HandlerOptions{
    ante.HandlerOptions{
    UnorderedNonceManager: app.AccountKeeper,
    AccountKeeper:         app.AccountKeeper,
    BankKeeper:            app.BankKeeper,
    SignModeHandler:       txConfig.SignModeHandler(),
    FeegrantKeeper:        app.FeeGrantKeeper,
    SigGasConsumer:        ante.DefaultSigVerificationGasConsumer,
},
			&app.CircuitKeeper,
},
	)
    if err != nil {
    panic(err)
}

	/ Set the AnteHandler for the app
	app.SetAnteHandler(anteHandler)
}

func (app *SimApp)

setPostHandler() {
    postHandler, err := posthandler.NewPostHandler(
		posthandler.HandlerOptions{
},
	)
    if err != nil {
    panic(err)
}

app.SetPostHandler(postHandler)
}

/ Name returns the name of the App
func (app *SimApp)

Name()

string {
    return app.BaseApp.Name()
}

/ PreBlocker application updates every pre block
func (app *SimApp)

PreBlocker(ctx sdk.Context, _ *abci.RequestFinalizeBlock) (*sdk.ResponsePreBlock, error) {
    return app.ModuleManager.PreBlock(ctx)
}

/ BeginBlocker application updates every begin block
func (app *SimApp)

BeginBlocker(ctx sdk.Context) (sdk.BeginBlock, error) {
    return app.ModuleManager.BeginBlock(ctx)
}

/ EndBlocker application updates every end block
func (app *SimApp)

EndBlocker(ctx sdk.Context) (sdk.EndBlock, error) {
    return app.ModuleManager.EndBlock(ctx)
}

func (a *SimApp)

Configurator()

module.Configurator {
    return a.configurator
}

/ InitChainer application update at chain initialization
func (app *SimApp)

InitChainer(ctx sdk.Context, req *abci.RequestInitChain) (*abci.ResponseInitChain, error) {
    var genesisState GenesisState
    if err := json.Unmarshal(req.AppStateBytes, &genesisState); err != nil {
    panic(err)
}

app.UpgradeKeeper.SetModuleVersionMap(ctx, app.ModuleManager.GetVersionMap())

return app.ModuleManager.InitGenesis(ctx, app.appCodec, genesisState)
}

/ LoadHeight loads a particular height
func (app *SimApp)

LoadHeight(height int64)

error {
    return app.LoadVersion(height)
}

/ LegacyAmino returns SimApp's amino codec.
/
/ NOTE: This is solely to be used for testing purposes as it may be desirable
/ for modules to register their own custom testing types.
func (app *SimApp)

LegacyAmino() *codec.LegacyAmino {
    return app.legacyAmino
}

/ AppCodec returns SimApp's app codec.
/
/ NOTE: This is solely to be used for testing purposes as it may be desirable
/ for modules to register their own custom testing types.
func (app *SimApp)

AppCodec()

codec.Codec {
    return app.appCodec
}

/ InterfaceRegistry returns SimApp's InterfaceRegistry
func (app *SimApp)

InterfaceRegistry()

types.InterfaceRegistry {
    return app.interfaceRegistry
}

/ TxConfig returns SimApp's TxConfig
func (app *SimApp)

TxConfig()

client.TxConfig {
    return app.txConfig
}

/ AutoCliOpts returns the autocli options for the app.
func (app *SimApp)

AutoCliOpts()

autocli.AppOptions {
    modules := make(map[string]appmodule.AppModule, 0)
    for _, m := range app.ModuleManager.Modules {
    if moduleWithName, ok := m.(module.HasName); ok {
    moduleName := moduleWithName.Name()
    if appModule, ok := moduleWithName.(appmodule.AppModule); ok {
    modules[moduleName] = appModule
}
	
}
	
}

return autocli.AppOptions{
    Modules:               modules,
    ModuleOptions:         runtimeservices.ExtractAutoCLIOptions(app.ModuleManager.Modules),
    AddressCodec:          authcodec.NewBech32Codec(sdk.GetConfig().GetBech32AccountAddrPrefix()),
    ValidatorAddressCodec: authcodec.NewBech32Codec(sdk.GetConfig().GetBech32ValidatorAddrPrefix()),
    ConsensusAddressCodec: authcodec.NewBech32Codec(sdk.GetConfig().GetBech32ConsensusAddrPrefix()),
}
}

/ DefaultGenesis returns a default genesis from the registered AppModuleBasic's.
func (a *SimApp)

DefaultGenesis()

map[string]json.RawMessage {
    return a.BasicModuleManager.DefaultGenesis(a.appCodec)
}

/ GetKey returns the KVStoreKey for the provided store key.
/
/ NOTE: This is solely to be used for testing purposes.
func (app *SimApp)

GetKey(storeKey string) *storetypes.KVStoreKey {
    return app.keys[storeKey]
}

/ GetStoreKeys returns all the stored store keys.
func (app *SimApp)

GetStoreKeys() []storetypes.StoreKey {
    keys := make([]storetypes.StoreKey, 0, len(app.keys))
    for _, key := range app.keys {
    keys = append(keys, key)
}

return keys
}

/ SimulationManager implements the SimulationApp interface
func (app *SimApp)

SimulationManager() *module.SimulationManager {
    return app.sm
}

/ RegisterAPIRoutes registers all application module routes with the provided
/ API server.
func (app *SimApp)

RegisterAPIRoutes(apiSvr *api.Server, apiConfig config.APIConfig) {
    clientCtx := apiSvr.ClientCtx
	/ Register new tx routes from grpc-gateway.
	authtx.RegisterGRPCGatewayRoutes(clientCtx, apiSvr.GRPCGatewayRouter)

	/ Register new CometBFT queries routes from grpc-gateway.
	cmtservice.RegisterGRPCGatewayRoutes(clientCtx, apiSvr.GRPCGatewayRouter)

	/ Register node gRPC service for grpc-gateway.
	nodeservice.RegisterGRPCGatewayRoutes(clientCtx, apiSvr.GRPCGatewayRouter)

	/ Register grpc-gateway routes for all modules.
	app.BasicModuleManager.RegisterGRPCGatewayRoutes(clientCtx, apiSvr.GRPCGatewayRouter)

	/ register swagger API from root so that other applications can override easily
    if err := server.RegisterSwaggerAPI(apiSvr.ClientCtx, apiSvr.Router, apiConfig.Swagger); err != nil {
    panic(err)
}
}

/ RegisterTxService implements the Application.RegisterTxService method.
func (app *SimApp)

RegisterTxService(clientCtx client.Context) {
    authtx.RegisterTxService(app.BaseApp.GRPCQueryRouter(), clientCtx, app.BaseApp.Simulate, app.interfaceRegistry)
}

/ RegisterTendermintService implements the Application.RegisterTendermintService method.
func (app *SimApp)

RegisterTendermintService(clientCtx client.Context) {
    cmtApp := server.NewCometABCIWrapper(app)

cmtservice.RegisterTendermintService(
		clientCtx,
		app.BaseApp.GRPCQueryRouter(),
		app.interfaceRegistry,
		cmtApp.Query,
	)
}

func (app *SimApp)

RegisterNodeService(clientCtx client.Context, cfg config.Config) {
    nodeservice.RegisterNodeService(clientCtx, app.GRPCQueryRouter(), cfg)
}

/ GetMaccPerms returns a copy of the module account permissions
/
/ NOTE: This is solely to be used for testing purposes.
func GetMaccPerms()

map[string][]string {
    return maps.Clone(maccPerms)
}

/ BlockedAddresses returns all the app's blocked account addresses.
func BlockedAddresses()

map[string]bool {
    modAccAddrs := make(map[string]bool)
    for acc := range GetMaccPerms() {
    modAccAddrs[authtypes.NewModuleAddress(acc).String()] = true
}

	/ allow the following addresses to receive funds
	delete(modAccAddrs, authtypes.NewModuleAddress(govtypes.ModuleName).String())

return modAccAddrs
}
The following diagram shows the current dependencies between keepers. Keeper dependencies