This section is intended to provide an overview of the SimApp app.go file and is still a work in progress. For now please instead read the tutorials for a deep dive on how to build a chain.

Complete app.go​

simapp/app.go
//go:build app_v1

package simapp

import (
	"encoding/json"
	"fmt"
	"io"
	"os"
	"path/filepath"

	"cosmossdk.io/log"
	"cosmossdk.io/x/tx/signing"

	autocliv1 "cosmossdk.io/api/cosmos/autocli/v1"
	reflectionv1 "cosmossdk.io/api/cosmos/reflection/v1"
	"cosmossdk.io/client/v2/autocli"
	"cosmossdk.io/core/appmodule"

	"github.com/cosmos/cosmos-sdk/codec/address"

	authcodec "github.com/cosmos/cosmos-sdk/x/auth/codec"
	"github.com/cosmos/cosmos-sdk/x/auth/tx"

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

	storetypes "cosmossdk.io/store/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/upgrade"
	upgradekeeper "cosmossdk.io/x/upgrade/keeper"
	upgradetypes "cosmossdk.io/x/upgrade/types"

	"cosmossdk.io/x/circuit"
	circuitkeeper "cosmossdk.io/x/circuit/keeper"
	circuittypes "cosmossdk.io/x/circuit/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/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"
	"github.com/cosmos/cosmos-sdk/version"
	"github.com/cosmos/cosmos-sdk/x/auth"
	"github.com/cosmos/cosmos-sdk/x/auth/ante"
	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"
	authtx "github.com/cosmos/cosmos-sdk/x/auth/tx"
	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"
	"github.com/cosmos/cosmos-sdk/x/crisis"
	crisiskeeper "github.com/cosmos/cosmos-sdk/x/crisis/keeper"
	crisistypes "github.com/cosmos/cosmos-sdk/x/crisis/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/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/params"
	paramsclient "github.com/cosmos/cosmos-sdk/x/params/client"
	paramskeeper "github.com/cosmos/cosmos-sdk/x/params/keeper"
	paramstypes "github.com/cosmos/cosmos-sdk/x/params/types"
	paramproposal "github.com/cosmos/cosmos-sdk/x/params/types/proposal"
	"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,
	}
)

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

// stdAccAddressCodec is a temporary address codec that we will use until we
// can populate it with the correct bech32 prefixes without depending on the global.
type stdAccAddressCodec struct{}

func (g stdAccAddressCodec) StringToBytes(text string) ([]byte, error) {
	if text == "" {
		return nil, nil
	}
	return sdk.AccAddressFromBech32(text)
}

func (g stdAccAddressCodec) BytesToString(bz []byte) (string, error) {
	if bz == nil {
		return "", nil
	}
	return sdk.AccAddress(bz).String(), nil
}

// stdValAddressCodec is a temporary address codec that we will use until we
// can populate it with the correct bech32 prefixes without depending on the global.
type stdValAddressCodec struct{}

func (g stdValAddressCodec) StringToBytes(text string) ([]byte, error) {
	return sdk.ValAddressFromBech32(text)
}

func (g stdValAddressCodec) BytesToString(bz []byte) (string, error) {
	return sdk.ValAddress(bz).String(), 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
	tkeys map[string]*storetypes.TransientStoreKey

	// keepers
	AccountKeeper         authkeeper.AccountKeeper
	BankKeeper            bankkeeper.Keeper
	StakingKeeper         *stakingkeeper.Keeper
	SlashingKeeper        slashingkeeper.Keeper
	MintKeeper            mintkeeper.Keeper
	DistrKeeper           distrkeeper.Keeper
	GovKeeper             govkeeper.Keeper
	CrisisKeeper          *crisiskeeper.Keeper
	UpgradeKeeper         *upgradekeeper.Keeper
	ParamsKeeper          paramskeeper.Keeper
	AuthzKeeper           authzkeeper.Keeper
	EvidenceKeeper        evidencekeeper.Keeper
	FeeGrantKeeper        feegrantkeeper.Keeper
	GroupKeeper           groupkeeper.Keeper
	NFTKeeper             nftkeeper.Keeper
	ConsensusParamsKeeper consensusparamkeeper.Keeper
	CircuitKeeper         circuitkeeper.Keeper

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

	// simulation manager
	sm *module.SimulationManager

	// module configurator
	configurator module.Configurator
}

func init() {
	userHomeDir, err := os.UserHomeDir()
	if err != nil {
		panic(err)
	}

	DefaultNodeHome = filepath.Join(userHomeDir, ".simapp")
}

// 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)

	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)

	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, crisistypes.StoreKey,
		minttypes.StoreKey, distrtypes.StoreKey, slashingtypes.StoreKey,
		govtypes.StoreKey, paramstypes.StoreKey, consensusparamtypes.StoreKey, upgradetypes.StoreKey, feegrant.StoreKey,
		evidencetypes.StoreKey, circuittypes.StoreKey,
		authzkeeper.StoreKey, nftkeeper.StoreKey, group.StoreKey,
	)

	// register streaming services
	if err := bApp.RegisterStreamingServices(appOpts, keys); err != nil {
		panic(err)
	}

	tkeys := storetypes.NewTransientStoreKeys(paramstypes.TStoreKey)
	app := &SimApp{
		BaseApp:           bApp,
		legacyAmino:       legacyAmino,
		appCodec:          appCodec,
		txConfig:          txConfig,
		interfaceRegistry: interfaceRegistry,
		keys:              keys,
		tkeys:             tkeys,
	}

	app.ParamsKeeper = initParamsKeeper(appCodec, legacyAmino, keys[paramstypes.StoreKey], tkeys[paramstypes.TStoreKey])

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

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

	invCheckPeriod := cast.ToUint(appOpts.Get(server.FlagInvCheckPeriod))
	app.CrisisKeeper = crisiskeeper.NewKeeper(appCodec, runtime.NewKVStoreService(keys[crisistypes.StoreKey]), invCheckPeriod,
		app.BankKeeper, authtypes.FeeCollectorName, authtypes.NewModuleAddress(govtypes.ModuleName).String(), app.AccountKeeper.AddressCodec())

	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).
		AddRoute(paramproposal.RouterKey, params.NewParamChangeProposalHandler(app.ParamsKeeper)).
		AddRoute(upgradetypes.RouterKey, upgrade.NewSoftwareUpgradeProposalHandler(app.UpgradeKeeper))
	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

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

	// NOTE: we may consider parsing `appOpts` inside module constructors. For the moment
	// we prefer to be more strict in what arguments the modules expect.
	skipGenesisInvariants := cast.ToBool(appOpts.Get(crisis.FlagSkipGenesisInvariants))

	// 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, app.GetSubspace(authtypes.ModuleName)),
		vesting.NewAppModule(app.AccountKeeper, app.BankKeeper),
		bank.NewAppModule(appCodec, app.BankKeeper, app.AccountKeeper, app.GetSubspace(banktypes.ModuleName)),
		crisis.NewAppModule(app.CrisisKeeper, skipGenesisInvariants, app.GetSubspace(crisistypes.ModuleName)),
		feegrantmodule.NewAppModule(appCodec, app.AccountKeeper, app.BankKeeper, app.FeeGrantKeeper, app.interfaceRegistry),
		gov.NewAppModule(appCodec, &app.GovKeeper, app.AccountKeeper, app.BankKeeper, app.GetSubspace(govtypes.ModuleName)),
		mint.NewAppModule(appCodec, app.MintKeeper, app.AccountKeeper, nil, app.GetSubspace(minttypes.ModuleName)),
		slashing.NewAppModule(appCodec, app.SlashingKeeper, app.AccountKeeper, app.BankKeeper, app.StakingKeeper, app.GetSubspace(slashingtypes.ModuleName), app.interfaceRegistry),
		distr.NewAppModule(appCodec, app.DistrKeeper, app.AccountKeeper, app.BankKeeper, app.StakingKeeper, app.GetSubspace(distrtypes.ModuleName)),
		staking.NewAppModule(appCodec, app.StakingKeeper, app.AccountKeeper, app.BankKeeper, app.GetSubspace(stakingtypes.ModuleName)),
		upgrade.NewAppModule(app.UpgradeKeeper, app.AccountKeeper.AddressCodec()),
		evidence.NewAppModule(app.EvidenceKeeper),
		params.NewAppModule(app.ParamsKeeper),
		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),
	)

	// 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{
					paramsclient.ProposalHandler,
				},
			),
		})
	app.BasicModuleManager.RegisterLegacyAminoCodec(legacyAmino)
	app.BasicModuleManager.RegisterInterfaces(interfaceRegistry)

	// 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(
		upgradetypes.ModuleName,
		minttypes.ModuleName,
		distrtypes.ModuleName,
		slashingtypes.ModuleName,
		evidencetypes.ModuleName,
		stakingtypes.ModuleName,
		genutiltypes.ModuleName,
		authz.ModuleName,
	)
	app.ModuleManager.SetOrderEndBlockers(
		crisistypes.ModuleName,
		govtypes.ModuleName,
		stakingtypes.ModuleName,
		genutiltypes.ModuleName,
		feegrant.ModuleName,
		group.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, crisistypes.ModuleName, genutiltypes.ModuleName, evidencetypes.ModuleName, authz.ModuleName,
		feegrant.ModuleName, nft.ModuleName, group.ModuleName, paramstypes.ModuleName, upgradetypes.ModuleName,
		vestingtypes.ModuleName, consensusparamtypes.ModuleName, circuittypes.ModuleName,
	}
	app.ModuleManager.SetOrderInitGenesis(genesisModuleOrder...)
	app.ModuleManager.SetOrderExportGenesis(genesisModuleOrder...)

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

	app.ModuleManager.RegisterInvariants(app.CrisisKeeper)
	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, app.GetSubspace(authtypes.ModuleName)),
	}
	app.sm = module.NewSimulationManagerFromAppModules(app.ModuleManager.Modules, overrideModules)

	app.sm.RegisterStoreDecoders()

	// initialize stores
	app.MountKVStores(keys)
	app.MountTransientStores(tkeys)

	// initialize BaseApp
	app.SetInitChainer(app.InitChainer)
	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, which comprises of only
	// one decorator: the Transaction Tips decorator. However, some chains do
	// not need it by default, so feel free to comment the next line if you do
	// not need tips.
	// To read more about tips:
	// https://docs.cosmos.network/main/core/tips.html
	//
	// 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{
				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() }

// 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,
		AddressCodec: authcodec.NewBech32Codec(sdk.GetConfig().GetBech32AccountAddrPrefix()),
	}
}

// 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, len(app.keys))
	for _, key := range app.keys {
		keys = append(keys, key)
	}

	return keys
}

// GetSubspace returns a param subspace for a given module name.
//
// NOTE: This is solely to be used for testing purposes.
func (app *SimApp) GetSubspace(moduleName string) paramstypes.Subspace {
	subspace, _ := app.ParamsKeeper.GetSubspace(moduleName)
	return subspace
}

// 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 {
	dupMaccPerms := make(map[string][]string)
	for k, v := range maccPerms {
		dupMaccPerms[k] = v
	}

	return dupMaccPerms
}

// 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
}

// initParamsKeeper init params keeper and its subspaces
func initParamsKeeper(appCodec codec.BinaryCodec, legacyAmino *codec.LegacyAmino, key, tkey storetypes.StoreKey) paramskeeper.Keeper {
	paramsKeeper := paramskeeper.NewKeeper(appCodec, legacyAmino, key, tkey)

	paramsKeeper.Subspace(authtypes.ModuleName)
	paramsKeeper.Subspace(banktypes.ModuleName)
	paramsKeeper.Subspace(stakingtypes.ModuleName)
	paramsKeeper.Subspace(minttypes.ModuleName)
	paramsKeeper.Subspace(distrtypes.ModuleName)
	paramsKeeper.Subspace(slashingtypes.ModuleName)
	paramsKeeper.Subspace(govtypes.ModuleName)
	paramsKeeper.Subspace(crisistypes.ModuleName)

	return paramsKeeper
}
See full example on GitHub