> ## Documentation Index
> Fetch the complete documentation index at: https://docs.cosmos.network/llms.txt
> Use this file to discover all available pages before exploring further.

# CheckTx

> CheckTx is called by the BaseApp when comet receives a transaction from a client, over the p2p network or RPC. The CheckTx method is responsible for validating the transaction and returning an error if the transaction is invalid.

CheckTx is called by the `BaseApp` when CometBFT receives a transaction from a client, over the p2p network or RPC. The CheckTx method is responsible for validating the transaction and returning an error if the transaction is invalid.

```mermaid theme={"theme":{"light":"github-light-high-contrast","dark":"github-dark-high-contrast"}}
graph TD
    subgraph SDK[Cosmos SDK]
        B[BaseApp]
        A[AnteHandlers]
        B <-->|Validate TX| A
    end
    C[CometBFT] <-->|CheckTx|SDK
    U((User)) -->|Submit TX| C
    N[P2P] -->|Receive TX| C
```

```go expandable theme={"theme":{"light":"github-light-high-contrast","dark":"github-dark-high-contrast"}}
package baseapp

import (
    
	"context"
    "errors"
    "fmt"
    "sort"
    "strings"
    "time"

	abcitypes "github.com/cometbft/cometbft/abci/types"
	abci "github.com/cometbft/cometbft/api/cometbft/abci/v1"
	cmtproto "github.com/cometbft/cometbft/api/cometbft/types/v1"
    "github.com/cosmos/gogoproto/proto"
    "google.golang.org/grpc/codes"
	grpcstatus "google.golang.org/grpc/status"

	corecomet "cosmossdk.io/core/comet"
	coreheader "cosmossdk.io/core/header"
	errorsmod "cosmossdk.io/errors"
    "cosmossdk.io/store/rootmulti"
	snapshottypes "cosmossdk.io/store/snapshots/types"
	storetypes "cosmossdk.io/store/types"
    "github.com/cosmos/cosmos-sdk/codec"
    "github.com/cosmos/cosmos-sdk/telemetry"
	sdk "github.com/cosmos/cosmos-sdk/types"
	sdkerrors "github.com/cosmos/cosmos-sdk/types/errors"
)

// Supported ABCI Query prefixes and paths
const (
	QueryPathApp    = "app"
	QueryPathCustom = "custom"
	QueryPathP2P    = "p2p"
	QueryPathStore  = "store"

	QueryPathBroadcastTx = "/cosmos.tx.v1beta1.Service/BroadcastTx"
)

// InitChain implements the ABCI interface. It initializes the application's state
// and sets up the initial validator set.
func (app *BaseApp)

InitChain(req *abci.InitChainRequest) (*abci.InitChainResponse, error) {
    if req.ChainId != app.chainID {
    return nil, fmt.Errorf("invalid chain-id on InitChain; expected: %s, got: %s", app.chainID, req.ChainId)
}

	// On a new chain, we consider the init chain block height as 0, even though
	// req.InitialHeight is 1 by default.
    initHeader := cmtproto.Header{
    ChainID: req.ChainId,
    Time: req.Time
}

app.logger.Info("InitChain", "initialHeight", req.InitialHeight, "chainID", req.ChainId)

	// Set the initial height, which will be used to determine if we are proposing
	// or processing the first block or not.
	app.initialHeight = req.InitialHeight
    if app.initialHeight == 0 { // If initial height is 0, set it to 1
		app.initialHeight = 1
}

	// if req.InitialHeight is > 1, then we set the initial version on all stores
    if req.InitialHeight > 1 {
    initHeader.Height = req.InitialHeight
    if err := app.cms.SetInitialVersion(req.InitialHeight); err != nil {
    return nil, err
}
	
}

	// initialize states with a correct header
	app.setState(execModeFinalize, initHeader)

app.setState(execModeCheck, initHeader)

	// Store the consensus params in the BaseApp's param store. Note, this must be
	// done after the finalizeBlockState and context have been set as it's persisted
	// to state.
    if req.ConsensusParams != nil {
    err := app.StoreConsensusParams(app.finalizeBlockState.Context(), *req.ConsensusParams)
    if err != nil {
    return nil, err
}
	
}

defer func() {
		// InitChain represents the state of the application BEFORE the first block,
		// i.e. the genesis block. This means that when processing the app's InitChain
		// handler, the block height is zero by default. However, after Commit is called
		// the height needs to reflect the true block height.
		initHeader.Height = req.InitialHeight
		app.checkState.SetContext(app.checkState.Context().WithBlockHeader(initHeader).
			WithHeaderInfo(coreheader.Info{
    ChainID: req.ChainId,
    Height:  req.InitialHeight,
    Time:    req.Time,
}))

app.finalizeBlockState.SetContext(app.finalizeBlockState.Context().WithBlockHeader(initHeader).
			WithHeaderInfo(coreheader.Info{
    ChainID: req.ChainId,
    Height:  req.InitialHeight,
    Time:    req.Time,
}))
}()
    if app.initChainer == nil {
    return &abci.InitChainResponse{
}, nil
}

	// add block gas meter for any genesis transactions (allow infinite gas)

app.finalizeBlockState.SetContext(app.finalizeBlockState.Context().WithBlockGasMeter(storetypes.NewInfiniteGasMeter()))

res, err := app.initChainer(app.finalizeBlockState.Context(), req)
    if err != nil {
    return nil, err
}
    if len(req.Validators) > 0 {
    if len(req.Validators) != len(res.Validators) {
    return nil, fmt.Errorf(
				"len(RequestInitChain.Validators) != len(GenesisValidators) (%d != %d)",
				len(req.Validators), len(res.Validators),
			)
}

sort.Sort(abcitypes.ValidatorUpdates(req.Validators))
    for i := range res.Validators {
    if !proto.Equal(&res.Validators[i], &req.Validators[i]) {
    return nil, fmt.Errorf("genesisValidators[%d] != req.Validators[%d] ", i, i)
}
	
}
	
}

	// NOTE: We don't commit, but FinalizeBlock for block InitialHeight starts from
	// this FinalizeBlockState.
	return &abci.InitChainResponse{
    ConsensusParams: res.ConsensusParams,
    Validators:      res.Validators,
    AppHash:         app.LastCommitID().Hash,
}, nil
}

// Info implements the ABCI interface. It returns information about the application.
func (app *BaseApp)

Info(_ *abci.InfoRequest) (*abci.InfoResponse, error) {
    lastCommitID := app.cms.LastCommitID()
    appVersion := InitialAppVersion
    if lastCommitID.Version > 0 {
    ctx, err := app.CreateQueryContext(lastCommitID.Version, false)
    if err != nil {
    return nil, fmt.Errorf("failed creating query context: %w", err)
}

appVersion, err = app.AppVersion(ctx)
    if err != nil {
    return nil, fmt.Errorf("failed getting app version: %w", err)
}
	
}

return &abci.InfoResponse{
    Data:             app.name,
    Version:          app.version,
    AppVersion:       appVersion,
    LastBlockHeight:  lastCommitID.Version,
    LastBlockAppHash: lastCommitID.Hash,
}, nil
}

// Query implements the ABCI interface. It delegates to CommitMultiStore if it
// implements Queryable.
func (app *BaseApp)

Query(_ context.Context, req *abci.QueryRequest) (resp *abci.QueryResponse, err error) {
	// add panic recovery for all queries
	//
	// Ref: https://github.com/cosmos/cosmos-sdk/pull/8039
	defer func() {
    if r := recover(); r != nil {
    resp = queryResult(errorsmod.Wrapf(sdkerrors.ErrPanic, "%v", r), app.trace)
}
	
}()

	// when a client did not provide a query height, manually inject the latest
    if req.Height == 0 {
    req.Height = app.LastBlockHeight()
}

telemetry.IncrCounter(1, "query", "count")

telemetry.IncrCounter(1, "query", req.Path)
    start := telemetry.Now()

defer telemetry.MeasureSince(start, req.Path)
    if req.Path == QueryPathBroadcastTx {
    return queryResult(errorsmod.Wrap(sdkerrors.ErrInvalidRequest, "can't route a broadcast tx message"), app.trace), nil
}

	// handle gRPC routes first rather than calling splitPath because '/' characters
	// are used as part of gRPC paths
    if grpcHandler := app.grpcQueryRouter.Route(req.Path); grpcHandler != nil {
    return app.handleQueryGRPC(grpcHandler, req), nil
}
    path := SplitABCIQueryPath(req.Path)
    if len(path) == 0 {
    return queryResult(errorsmod.Wrap(sdkerrors.ErrUnknownRequest, "no query path provided"), app.trace), nil
}
    switch path[0] {
    case QueryPathApp:
		// "/app" prefix for special application queries
		resp = handleQueryApp(app, path, req)
    case QueryPathStore:
		resp = handleQueryStore(app, path, *req)
    case QueryPathP2P:
		resp = handleQueryP2P(app, path)

default:
		resp = queryResult(errorsmod.Wrap(sdkerrors.ErrUnknownRequest, "unknown query path"), app.trace)
}

return resp, nil
}

// ListSnapshots implements the ABCI interface. It delegates to app.snapshotManager if set.
func (app *BaseApp)

ListSnapshots(req *abci.ListSnapshotsRequest) (*abci.ListSnapshotsResponse, error) {
    resp := &abci.ListSnapshotsResponse{
    Snapshots: []*abci.Snapshot{
}}
    if app.snapshotManager == nil {
    return resp, nil
}

snapshots, err := app.snapshotManager.List()
    if err != nil {
    app.logger.Error("failed to list snapshots", "err", err)

return nil, err
}
    for _, snapshot := range snapshots {
    abciSnapshot, err := snapshot.ToABCI()
    if err != nil {
    app.logger.Error("failed to convert ABCI snapshots", "err", err)

return nil, err
}

resp.Snapshots = append(resp.Snapshots, &abciSnapshot)
}

return resp, nil
}

// LoadSnapshotChunk implements the ABCI interface. It delegates to app.snapshotManager if set.
func (app *BaseApp)

LoadSnapshotChunk(req *abci.LoadSnapshotChunkRequest) (*abci.LoadSnapshotChunkResponse, error) {
    if app.snapshotManager == nil {
    return &abci.LoadSnapshotChunkResponse{
}, nil
}

chunk, err := app.snapshotManager.LoadChunk(req.Height, req.Format, req.Chunk)
    if err != nil {
    app.logger.Error(
			"failed to load snapshot chunk",
			"height", req.Height,
			"format", req.Format,
			"chunk", req.Chunk,
			"err", err,
		)

return nil, err
}

return &abci.LoadSnapshotChunkResponse{
    Chunk: chunk
}, nil
}

// OfferSnapshot implements the ABCI interface. It delegates to app.snapshotManager if set.
func (app *BaseApp)

OfferSnapshot(req *abci.OfferSnapshotRequest) (*abci.OfferSnapshotResponse, error) {
    if app.snapshotManager == nil {
    app.logger.Error("snapshot manager not configured")

return &abci.OfferSnapshotResponse{
    Result: abci.OFFER_SNAPSHOT_RESULT_ABORT
}, nil
}
    if req.Snapshot == nil {
    app.logger.Error("received nil snapshot")

return &abci.OfferSnapshotResponse{
    Result: abci.OFFER_SNAPSHOT_RESULT_REJECT
}, nil
}

snapshot, err := snapshottypes.SnapshotFromABCI(req.Snapshot)
    if err != nil {
    app.logger.Error("failed to decode snapshot metadata", "err", err)

return &abci.OfferSnapshotResponse{
    Result: abci.OFFER_SNAPSHOT_RESULT_REJECT
}, nil
}

err = app.snapshotManager.Restore(snapshot)
    switch {
    case err == nil:
		return &abci.OfferSnapshotResponse{
    Result: abci.OFFER_SNAPSHOT_RESULT_ACCEPT
}, nil
    case errors.Is(err, snapshottypes.ErrUnknownFormat):
		return &abci.OfferSnapshotResponse{
    Result: abci.OFFER_SNAPSHOT_RESULT_REJECT_FORMAT
}, nil
    case errors.Is(err, snapshottypes.ErrInvalidMetadata):
		app.logger.Error(
			"rejecting invalid snapshot",
			"height", req.Snapshot.Height,
			"format", req.Snapshot.Format,
			"err", err,
		)

return &abci.OfferSnapshotResponse{
    Result: abci.OFFER_SNAPSHOT_RESULT_REJECT
}, nil

	default:
		// CometBFT errors are defined here: https://github.com/cometbft/cometbft/blob/main/statesync/syncer.go
		// It may happen that in case of a CometBFT error, such as a timeout (which occurs after two minutes),
		// the process is aborted. This is done intentionally because deleting the database programmatically
		// can lead to more complicated situations.
		app.logger.Error(
			"failed to restore snapshot",
			"height", req.Snapshot.Height,
			"format", req.Snapshot.Format,
			"err", err,
		)

		// We currently don't support resetting the IAVL stores and retrying a
		// different snapshot, so we ask CometBFT to abort all snapshot restoration.
		return &abci.OfferSnapshotResponse{
    Result: abci.OFFER_SNAPSHOT_RESULT_ABORT
}, nil
}
}

// ApplySnapshotChunk implements the ABCI interface. It delegates to app.snapshotManager if set.
func (app *BaseApp)

ApplySnapshotChunk(req *abci.ApplySnapshotChunkRequest) (*abci.ApplySnapshotChunkResponse, error) {
    if app.snapshotManager == nil {
    app.logger.Error("snapshot manager not configured")

return &abci.ApplySnapshotChunkResponse{
    Result: abci.APPLY_SNAPSHOT_CHUNK_RESULT_ABORT
}, nil
}

	_, err := app.snapshotManager.RestoreChunk(req.Chunk)
    switch {
    case err == nil:
		return &abci.ApplySnapshotChunkResponse{
    Result: abci.APPLY_SNAPSHOT_CHUNK_RESULT_ACCEPT
}, nil
    case errors.Is(err, snapshottypes.ErrChunkHashMismatch):
		app.logger.Error(
			"chunk checksum mismatch; rejecting sender and requesting refetch",
			"chunk", req.Index,
			"sender", req.Sender,
			"err", err,
		)

return &abci.ApplySnapshotChunkResponse{
    Result:        abci.APPLY_SNAPSHOT_CHUNK_RESULT_RETRY,
    RefetchChunks: []uint32{
    req.Index
},
    RejectSenders: []string{
    req.Sender
},
}, nil

	default:
		app.logger.Error("failed to restore snapshot", "err", err)

return &abci.ApplySnapshotChunkResponse{
    Result: abci.APPLY_SNAPSHOT_CHUNK_RESULT_ABORT
}, nil
}
}

// CheckTx implements the ABCI interface and executes a tx in CheckTx mode. In
// CheckTx mode, messages are not executed. This means messages are only validated
// and only the AnteHandler is executed. State is persisted to the BaseApp's
// internal CheckTx state if the AnteHandler passes. Otherwise, the ResponseCheckTx
// will contain relevant error information. Regardless of tx execution outcome,
// the ResponseCheckTx will contain relevant gas execution context.
func (app *BaseApp)

CheckTx(req *abci.CheckTxRequest) (*abci.CheckTxResponse, error) {
    var mode execMode
    switch {
    case req.Type == abci.CHECK_TX_TYPE_CHECK:
		mode = execModeCheck
    case req.Type == abci.CHECK_TX_TYPE_RECHECK:
		mode = execModeReCheck

	default:
		return nil, fmt.Errorf("unknown RequestCheckTx type: %s", req.Type)
}
    if app.checkTxHandler == nil {
    gInfo, result, anteEvents, err := app.runTx(mode, req.Tx, nil)
    if err != nil {
    return responseCheckTxWithEvents(err, gInfo.GasWanted, gInfo.GasUsed, anteEvents, app.trace), nil
}

return &abci.CheckTxResponse{
    GasWanted: int64(gInfo.GasWanted), // TODO: Should type accept unsigned ints?
			GasUsed:   int64(gInfo.GasUsed),   // TODO: Should type accept unsigned ints?
			Log:       result.Log,
    Data:      result.Data,
    Events:    sdk.MarkEventsToIndex(result.Events, app.indexEvents),
}, nil
}

return app.checkTxHandler(app.runTx, req)
}

// PrepareProposal implements the PrepareProposal ABCI method and returns a
// ResponsePrepareProposal object to the client. The PrepareProposal method is
// responsible for allowing the block proposer to perform application-dependent
// work in a block before proposing it.
//
// Transactions can be modified, removed, or added by the application. Since the
// application maintains its own local mempool, it will ignore the transactions
// provided to it in RequestPrepareProposal. Instead, it will determine which
// transactions to return based on the mempool's semantics and the MaxTxBytes
// provided by the client's request.
//
// Ref: https://github.com/cosmos/cosmos-sdk/blob/main/docs/architecture/adr-060-abci-1.0.md
// Ref: https://github.com/cometbft/cometbft/blob/main/spec/abci/abci%2B%2B_basic_concepts.md
func (app *BaseApp)

PrepareProposal(req *abci.PrepareProposalRequest) (resp *abci.PrepareProposalResponse, err error) {
    if app.prepareProposal == nil {
    return nil, errors.New("PrepareProposal handler not set")
}

	// Always reset state given that PrepareProposal can timeout and be called
	// again in a subsequent round.
    header := cmtproto.Header{
    ChainID:            app.chainID,
    Height:             req.Height,
    Time:               req.Time,
    ProposerAddress:    req.ProposerAddress,
    NextValidatorsHash: req.NextValidatorsHash,
    AppHash:            app.LastCommitID().Hash,
}

app.setState(execModePrepareProposal, header)

	// CometBFT must never call PrepareProposal with a height of 0.
	//
	// Ref: https://github.com/cometbft/cometbft/blob/059798a4f5b0c9f52aa8655fa619054a0154088c/spec/core/state.md?plain=1#L37-L38
    if req.Height < 1 {
    return nil, errors.New("PrepareProposal called with invalid height")
}

app.prepareProposalState.SetContext(app.getContextForProposal(app.prepareProposalState.Context(), req.Height).
		WithVoteInfos(toVoteInfo(req.LocalLastCommit.Votes)). // this is a set of votes that are not finalized yet, wait for commit
		WithBlockHeight(req.Height).
		WithProposer(req.ProposerAddress).
		WithExecMode(sdk.ExecModePrepareProposal).
		WithCometInfo(corecomet.Info{
    Evidence:        sdk.ToSDKEvidence(req.Misbehavior),
    ValidatorsHash:  req.NextValidatorsHash,
    ProposerAddress: req.ProposerAddress,
    LastCommit:      sdk.ToSDKExtendedCommitInfo(req.LocalLastCommit),
}).
		WithHeaderInfo(coreheader.Info{
    ChainID: app.chainID,
    Height:  req.Height,
    Time:    req.Time,
}))

app.prepareProposalState.SetContext(app.prepareProposalState.Context().
		WithConsensusParams(app.GetConsensusParams(app.prepareProposalState.Context())).
		WithBlockGasMeter(app.getBlockGasMeter(app.prepareProposalState.Context())))

defer func() {
    if err := recover(); err != nil {
    app.logger.Error(
				"panic recovered in PrepareProposal",
				"height", req.Height,
				"time", req.Time,
				"panic", err,
			)

resp = &abci.PrepareProposalResponse{
    Txs: req.Txs
}
	
}
	
}()

resp, err = app.prepareProposal(app.prepareProposalState.Context(), req)
    if err != nil {
    app.logger.Error("failed to prepare proposal", "height", req.Height, "time", req.Time, "err", err)

return &abci.PrepareProposalResponse{
    Txs: req.Txs
}, nil
}

return resp, nil
}

// ProcessProposal implements the ProcessProposal ABCI method and returns a
// ResponseProcessProposal object to the client. The ProcessProposal method is
// responsible for allowing execution of application-dependent work in a proposed
// block. Note, the application defines the exact implementation details of
// ProcessProposal. In general, the application must at the very least ensure
// that all transactions are valid. If all transactions are valid, then we inform
// CometBFT that the Status is ACCEPT. However, the application is also able
// to implement optimizations such as executing the entire proposed block
// immediately.
//
// If a panic is detected during execution of an application's ProcessProposal
// handler, it will be recovered and we will reject the proposal.
//
// Ref: https://github.com/cosmos/cosmos-sdk/blob/main/docs/architecture/adr-060-abci-1.0.md
// Ref: https://github.com/cometbft/cometbft/blob/main/spec/abci/abci%2B%2B_basic_concepts.md
func (app *BaseApp)

ProcessProposal(req *abci.ProcessProposalRequest) (resp *abci.ProcessProposalResponse, err error) {
    if app.processProposal == nil {
    return nil, errors.New("ProcessProposal handler not set")
}

	// CometBFT must never call ProcessProposal with a height of 0.
	// Ref: https://github.com/cometbft/cometbft/blob/059798a4f5b0c9f52aa8655fa619054a0154088c/spec/core/state.md?plain=1#L37-L38
    if req.Height < 1 {
    return nil, errors.New("ProcessProposal called with invalid height")
}

	// Always reset state given that ProcessProposal can timeout and be called
	// again in a subsequent round.
    header := cmtproto.Header{
    ChainID:            app.chainID,
    Height:             req.Height,
    Time:               req.Time,
    ProposerAddress:    req.ProposerAddress,
    NextValidatorsHash: req.NextValidatorsHash,
    AppHash:            app.LastCommitID().Hash,
}

app.setState(execModeProcessProposal, header)

	// Since the application can get access to FinalizeBlock state and write to it,
	// we must be sure to reset it in case ProcessProposal timeouts and is called
	// again in a subsequent round. However, we only want to do this after we've
	// processed the first block, as we want to avoid overwriting the finalizeState
	// after state changes during InitChain.
    if req.Height > app.initialHeight {
		// abort any running OE
		app.optimisticExec.Abort()

app.setState(execModeFinalize, header)
}

app.processProposalState.SetContext(app.getContextForProposal(app.processProposalState.Context(), req.Height).
		WithVoteInfos(req.ProposedLastCommit.Votes). // this is a set of votes that are not finalized yet, wait for commit
		WithBlockHeight(req.Height).
		WithHeaderHash(req.Hash).
		WithProposer(req.ProposerAddress).
		WithCometInfo(corecomet.Info{
    ProposerAddress: req.ProposerAddress,
    ValidatorsHash:  req.NextValidatorsHash,
    Evidence:        sdk.ToSDKEvidence(req.Misbehavior),
    LastCommit:      sdk.ToSDKCommitInfo(req.ProposedLastCommit),
},
		).
		WithExecMode(sdk.ExecModeProcessProposal).
		WithHeaderInfo(coreheader.Info{
    ChainID: app.chainID,
    Height:  req.Height,
    Time:    req.Time,
}))

app.processProposalState.SetContext(app.processProposalState.Context().
		WithConsensusParams(app.GetConsensusParams(app.processProposalState.Context())).
		WithBlockGasMeter(app.getBlockGasMeter(app.processProposalState.Context())))

defer func() {
    if err := recover(); err != nil {
    app.logger.Error(
				"panic recovered in ProcessProposal",
				"height", req.Height,
				"time", req.Time,
				"hash", fmt.Sprintf("%X", req.Hash),
				"panic", err,
			)

resp = &abci.ProcessProposalResponse{
    Status: abci.PROCESS_PROPOSAL_STATUS_REJECT
}
	
}
	
}()

resp, err = app.processProposal(app.processProposalState.Context(), req)
    if err != nil {
    app.logger.Error("failed to process proposal", "height", req.Height, "time", req.Time, "hash", fmt.Sprintf("%X", req.Hash), "err", err)

return &abci.ProcessProposalResponse{
    Status: abci.PROCESS_PROPOSAL_STATUS_REJECT
}, nil
}

	// Only execute optimistic execution if the proposal is accepted, OE is
	// enabled and the block height is greater than the initial height. During
	// the first block we'll be carrying state from InitChain, so it would be
	// impossible for us to easily revert.
	// After the first block has been processed, the next blocks will get executed
	// optimistically, so that when the ABCI client calls `FinalizeBlock` the app
	// can have a response ready.
    if resp.Status == abci.PROCESS_PROPOSAL_STATUS_ACCEPT &&
		app.optimisticExec.Enabled() &&
		req.Height > app.initialHeight {
    app.optimisticExec.Execute(req)
}

return resp, nil
}

// ExtendVote implements the ExtendVote ABCI method and returns a ResponseExtendVote.
// It calls the application's ExtendVote handler which is responsible for performing
// application-specific business logic when sending a pre-commit for the NEXT
// block height. The extensions response may be non-deterministic but must always
// be returned, even if empty.
//
// Agreed upon vote extensions are made available to the proposer of the next
// height and are committed in the subsequent height, i.e. H+2. An error is
// returned if vote extensions are not enabled or if extendVote fails or panics.
func (app *BaseApp)

ExtendVote(_ context.Context, req *abci.ExtendVoteRequest) (resp *abci.ExtendVoteResponse, err error) {
	// Always reset state given that ExtendVote and VerifyVoteExtension can timeout
	// and be called again in a subsequent round.
	var ctx sdk.Context

	// If we're extending the vote for the initial height, we need to use the
	// finalizeBlockState context, otherwise we don't get the uncommitted data
	// from InitChain.
    if req.Height == app.initialHeight {
    ctx, _ = app.finalizeBlockState.Context().CacheContext()
}

else {
    ms := app.cms.CacheMultiStore()

ctx = sdk.NewContext(ms, false, app.logger).WithStreamingManager(app.streamingManager).WithChainID(app.chainID).WithBlockHeight(req.Height)
}
    if app.extendVote == nil {
    return nil, errors.New("application ExtendVote handler not set")
}

	// If vote extensions are not enabled, as a safety precaution, we return an
	// error.
    cp := app.GetConsensusParams(ctx)

	// Note: In this case, we do want to extend vote if the height is equal or
	// greater than VoteExtensionsEnableHeight. This differs from the check done
	// in ValidateVoteExtensions and PrepareProposal in which we'll check for
	// vote extensions on VoteExtensionsEnableHeight+1.
    extsEnabled := cp.Feature != nil && req.Height >= cp.Feature.VoteExtensionsEnableHeight.Value && cp.Feature.VoteExtensionsEnableHeight.Value != 0
    if !extsEnabled {
		// check abci params
		extsEnabled = cp.Abci != nil && req.Height >= cp.Abci.VoteExtensionsEnableHeight && cp.Abci.VoteExtensionsEnableHeight != 0
    if !extsEnabled {
    return nil, fmt.Errorf("vote extensions are not enabled; unexpected call to ExtendVote at height %d", req.Height)
}
	
}

ctx = ctx.
		WithConsensusParams(cp).
		WithBlockGasMeter(storetypes.NewInfiniteGasMeter()).
		WithBlockHeight(req.Height).
		WithHeaderHash(req.Hash).
		WithExecMode(sdk.ExecModeVoteExtension).
		WithHeaderInfo(coreheader.Info{
    ChainID: app.chainID,
    Height:  req.Height,
    Hash:    req.Hash,
})

	// add a deferred recover handler in case extendVote panics
	defer func() {
    if r := recover(); r != nil {
    app.logger.Error(
				"panic recovered in ExtendVote",
				"height", req.Height,
				"hash", fmt.Sprintf("%X", req.Hash),
				"panic", err,
			)

err = fmt.Errorf("recovered application panic in ExtendVote: %v", r)
}
	
}()

resp, err = app.extendVote(ctx, req)
    if err != nil {
    app.logger.Error("failed to extend vote", "height", req.Height, "hash", fmt.Sprintf("%X", req.Hash), "err", err)

return &abci.ExtendVoteResponse{
    VoteExtension: []byte{
}}, nil
}

return resp, err
}

// VerifyVoteExtension implements the VerifyVoteExtension ABCI method and returns
// a ResponseVerifyVoteExtension. It calls the applications' VerifyVoteExtension
// handler which is responsible for performing application-specific business
// logic in verifying a vote extension from another validator during the pre-commit
// phase. The response MUST be deterministic. An error is returned if vote
// extensions are not enabled or if verifyVoteExt fails or panics.
// We highly recommend a size validation due to performance degradation,
// see more here /cometbft/v0.38/docs/qa/CometBFT-QA-38#vote-extensions-testbed
func (app *BaseApp)

VerifyVoteExtension(req *abci.VerifyVoteExtensionRequest) (resp *abci.VerifyVoteExtensionResponse, err error) {
    if app.verifyVoteExt == nil {
    return nil, errors.New("application VerifyVoteExtension handler not set")
}

var ctx sdk.Context

	// If we're verifying the vote for the initial height, we need to use the
	// finalizeBlockState context, otherwise we don't get the uncommitted data
	// from InitChain.
    if req.Height == app.initialHeight {
    ctx, _ = app.finalizeBlockState.Context().CacheContext()
}

else {
    ms := app.cms.CacheMultiStore()

ctx = sdk.NewContext(ms, false, app.logger).WithStreamingManager(app.streamingManager).WithChainID(app.chainID).WithBlockHeight(req.Height)
}

	// If vote extensions are not enabled, as a safety precaution, we return an
	// error.
    cp := app.GetConsensusParams(ctx)

	// Note: we verify vote extensions on VoteExtensionsEnableHeight+1. Check
	// comment in ExtendVote and ValidateVoteExtensions for more details.
    extsEnabled := cp.Feature.VoteExtensionsEnableHeight != nil && req.Height >= cp.Feature.VoteExtensionsEnableHeight.Value && cp.Feature.VoteExtensionsEnableHeight.Value != 0
    if !extsEnabled {
		// check abci params
		extsEnabled = cp.Abci != nil && req.Height >= cp.Abci.VoteExtensionsEnableHeight && cp.Abci.VoteExtensionsEnableHeight != 0
    if !extsEnabled {
    return nil, fmt.Errorf("vote extensions are not enabled; unexpected call to VerifyVoteExtension at height %d", req.Height)
}
	
}

	// add a deferred recover handler in case verifyVoteExt panics
	defer func() {
    if r := recover(); r != nil {
    app.logger.Error(
				"panic recovered in VerifyVoteExtension",
				"height", req.Height,
				"hash", fmt.Sprintf("%X", req.Hash),
				"validator", fmt.Sprintf("%X", req.ValidatorAddress),
				"panic", r,
			)

err = fmt.Errorf("recovered application panic in VerifyVoteExtension: %v", r)
}
	
}()

ctx = ctx.
		WithConsensusParams(cp).
		WithBlockGasMeter(storetypes.NewInfiniteGasMeter()).
		WithBlockHeight(req.Height).
		WithHeaderHash(req.Hash).
		WithExecMode(sdk.ExecModeVerifyVoteExtension).
		WithHeaderInfo(coreheader.Info{
    ChainID: app.chainID,
    Height:  req.Height,
    Hash:    req.Hash,
})

resp, err = app.verifyVoteExt(ctx, req)
    if err != nil {
    app.logger.Error("failed to verify vote extension", "height", req.Height, "err", err)

return &abci.VerifyVoteExtensionResponse{
    Status: abci.VERIFY_VOTE_EXTENSION_STATUS_REJECT
}, nil
}

return resp, err
}

// internalFinalizeBlock executes the block, called by the Optimistic
// Execution flow or by the FinalizeBlock ABCI method. The context received is
// only used to handle early cancellation, for anything related to state app.finalizeBlockState.Context()
// must be used.
func (app *BaseApp)

internalFinalizeBlock(ctx context.Context, req *abci.FinalizeBlockRequest) (*abci.FinalizeBlockResponse, error) {
    var events []abci.Event
    if err := app.checkHalt(req.Height, req.Time); err != nil {
    return nil, err
}
    if err := app.validateFinalizeBlockHeight(req); err != nil {
    return nil, err
}
    if app.cms.TracingEnabled() {
    app.cms.SetTracingContext(storetypes.TraceContext(
			map[string]any{"blockHeight": req.Height
},
		))
}
    header := cmtproto.Header{
    ChainID:            app.chainID,
    Height:             req.Height,
    Time:               req.Time,
    ProposerAddress:    req.ProposerAddress,
    NextValidatorsHash: req.NextValidatorsHash,
    AppHash:            app.LastCommitID().Hash,
}

	// finalizeBlockState should be set on InitChain or ProcessProposal. If it is
	// nil, it means we are replaying this block and we need to set the state here
	// given that during block replay ProcessProposal is not executed by CometBFT.
    if app.finalizeBlockState == nil {
    app.setState(execModeFinalize, header)
}

	// Context is now updated with Header information.
	app.finalizeBlockState.SetContext(app.finalizeBlockState.Context().
		WithBlockHeader(header).
		WithHeaderHash(req.Hash).
		WithHeaderInfo(coreheader.Info{
    ChainID: app.chainID,
    Height:  req.Height,
    Time:    req.Time,
    Hash:    req.Hash,
    AppHash: app.LastCommitID().Hash,
}).
		WithConsensusParams(app.GetConsensusParams(app.finalizeBlockState.Context())).
		WithVoteInfos(req.DecidedLastCommit.Votes).
		WithExecMode(sdk.ExecModeFinalize).
		WithCometInfo(corecomet.Info{
    Evidence:        sdk.ToSDKEvidence(req.Misbehavior),
    ValidatorsHash:  req.NextValidatorsHash,
    ProposerAddress: req.ProposerAddress,
    LastCommit:      sdk.ToSDKCommitInfo(req.DecidedLastCommit),
}))

	// GasMeter must be set after we get a context with updated consensus params.
    gasMeter := app.getBlockGasMeter(app.finalizeBlockState.Context())

app.finalizeBlockState.SetContext(app.finalizeBlockState.Context().WithBlockGasMeter(gasMeter))
    if app.checkState != nil {
    app.checkState.SetContext(app.checkState.Context().
			WithBlockGasMeter(gasMeter).
			WithHeaderHash(req.Hash))
}

preblockEvents, err := app.preBlock(req)
    if err != nil {
    return nil, err
}

events = append(events, preblockEvents...)

beginBlock, err := app.beginBlock(req)
    if err != nil {
    return nil, err
}

	// First check for an abort signal after beginBlock, as it's the first place
	// we spend any significant amount of time.
	select {
    case <-ctx.Done():
		return nil, ctx.Err()

default:
		// continue
}

events = append(events, beginBlock.Events...)

	// Reset the gas meter so that the AnteHandlers aren't required to
	gasMeter = app.getBlockGasMeter(app.finalizeBlockState.Context())

app.finalizeBlockState.SetContext(app.finalizeBlockState.Context().WithBlockGasMeter(gasMeter))

	// Iterate over all raw transactions in the proposal and attempt to execute
	// them, gathering the execution results.
	//
	// NOTE: Not all raw transactions may adhere to the sdk.Tx interface, e.g.
	// vote extensions, so skip those.
    txResults := make([]*abci.ExecTxResult, 0, len(req.Txs))
    for _, rawTx := range req.Txs {
    response := app.deliverTx(rawTx)

		// check after every tx if we should abort
		select {
    case <-ctx.Done():
			return nil, ctx.Err()

default:
			// continue
}

txResults = append(txResults, response)
}
    if app.finalizeBlockState.ms.TracingEnabled() {
    app.finalizeBlockState.ms = app.finalizeBlockState.ms.SetTracingContext(nil).(storetypes.CacheMultiStore)
}

endBlock, err := app.endBlock(app.finalizeBlockState.Context())
    if err != nil {
    return nil, err
}

	// check after endBlock if we should abort, to avoid propagating the result
	select {
    case <-ctx.Done():
		return nil, ctx.Err()

default:
		// continue
}

events = append(events, endBlock.Events...)
    cp := app.GetConsensusParams(app.finalizeBlockState.Context())

return &abci.FinalizeBlockResponse{
    Events:                events,
    TxResults:             txResults,
    ValidatorUpdates:      endBlock.ValidatorUpdates,
    ConsensusParamUpdates: &cp,
}, nil
}

// FinalizeBlock will execute the block proposal provided by RequestFinalizeBlock.
// Specifically, it will execute an application's BeginBlock (if defined), followed
// by the transactions in the proposal, finally followed by the application's
// EndBlock (if defined).
//
// For each raw transaction, i.e. a byte slice, BaseApp will only execute it if
// it adheres to the sdk.Tx interface. Otherwise, the raw transaction will be
// skipped. This is to support compatibility with proposers injecting vote
// extensions into the proposal, which should not themselves be executed in cases
// where they adhere to the sdk.Tx interface.
func (app *BaseApp)

FinalizeBlock(req *abci.FinalizeBlockRequest) (res *abci.FinalizeBlockResponse, err error) {
    defer func() {
		// call the streaming service hooks with the FinalizeBlock messages
    for _, streamingListener := range app.streamingManager.ABCIListeners {
    if err := streamingListener.ListenFinalizeBlock(app.finalizeBlockState.Context(), *req, *res); err != nil {
    app.logger.Error("ListenFinalizeBlock listening hook failed", "height", req.Height, "err", err)
}
	
}
	
}()
    if app.optimisticExec.Initialized() {
		// check if the hash we got is the same as the one we are executing
    aborted := app.optimisticExec.AbortIfNeeded(req.Hash)
		// Wait for the OE to finish, regardless of whether it was aborted or not
		res, err = app.optimisticExec.WaitResult()

		// only return if we are not aborting
    if !aborted {
    if res != nil {
    res.AppHash = app.workingHash()
}

return res, err
}

		// if it was aborted, we need to reset the state
		app.finalizeBlockState = nil
		app.optimisticExec.Reset()
}

	// if no OE is running, just run the block (this is either a block replay or a OE that got aborted)

res, err = app.internalFinalizeBlock(context.Background(), req)
    if res != nil {
    res.AppHash = app.workingHash()
}

return res, err
}

// checkHalt checks if height or time exceeds halt-height or halt-time respectively.
func (app *BaseApp)

checkHalt(height int64, time time.Time)

error {
    var halt bool
    switch {
    case app.haltHeight > 0 && uint64(height) >= app.haltHeight:
		halt = true
    case app.haltTime > 0 && time.Unix() >= int64(app.haltTime):
		halt = true
}
    if halt {
    return fmt.Errorf("halt per configuration height %d time %d", app.haltHeight, app.haltTime)
}

return nil
}

// Commit implements the ABCI interface. It will commit all state that exists in
// the deliver state's multi-store and includes the resulting commit ID in the
// returned abci.ResponseCommit. Commit will set the check state based on the
// latest header and reset the deliver state. Also, if a non-zero halt height is
// defined in config, Commit will execute a deferred function call to check
// against that height and gracefully halt if it matches the latest committed
// height.
func (app *BaseApp)

Commit() (*abci.CommitResponse, error) {
    header := app.finalizeBlockState.Context().BlockHeader()
    retainHeight := app.GetBlockRetentionHeight(header.Height)
    if app.precommiter != nil {
    app.precommiter(app.finalizeBlockState.Context())
}

rms, ok := app.cms.(*rootmulti.Store)
    if ok {
    rms.SetCommitHeader(header)
}

app.cms.Commit()
    resp := &abci.CommitResponse{
    RetainHeight: retainHeight,
}
    abciListeners := app.streamingManager.ABCIListeners
    if len(abciListeners) > 0 {
    ctx := app.finalizeBlockState.Context()
    blockHeight := ctx.BlockHeight()
    changeSet := app.cms.PopStateCache()
    for _, abciListener := range abciListeners {
    if err := abciListener.ListenCommit(ctx, *resp, changeSet); err != nil {
    app.logger.Error("Commit listening hook failed", "height", blockHeight, "err", err)
}
	
}
	
}

	// Reset the CheckTx state to the latest committed.
	//
	// NOTE: This is safe because CometBFT holds a lock on the mempool for
	// Commit. Use the header from this latest block.
	app.setState(execModeCheck, header)

app.finalizeBlockState = nil
    if app.prepareCheckStater != nil {
    app.prepareCheckStater(app.checkState.Context())
}

	// The SnapshotIfApplicable method will create the snapshot by starting the goroutine
	app.snapshotManager.SnapshotIfApplicable(header.Height)

return resp, nil
}

// workingHash gets the apphash that will be finalized in commit.
// These writes will be persisted to the root multi-store (app.cms)

and flushed to
// disk in the Commit phase. This means when the ABCI client requests Commit(), the application
// state transitions will be flushed to disk and as a result, but we already have
// an application Merkle root.
func (app *BaseApp)

workingHash() []byte {
	// Write the FinalizeBlock state into branched storage and commit the MultiStore.
	// The write to the FinalizeBlock state writes all state transitions to the root
	// MultiStore (app.cms)

so when Commit()

is called it persists those values.
	app.finalizeBlockState.ms.Write()

	// Get the hash of all writes in order to return the apphash to CometBFT in finalizeBlock.
    commitHash := app.cms.WorkingHash()

app.logger.Debug("hash of all writes", "workingHash", fmt.Sprintf("%X", commitHash))

return commitHash
}

func handleQueryApp(app *BaseApp, path []string, req *abci.QueryRequest) *abci.QueryResponse {
    if len(path) >= 2 {
    switch path[1] {
    case "simulate":
    txBytes := req.Data

			gInfo, res, err := app.Simulate(txBytes)
    if err != nil {
    return queryResult(errorsmod.Wrap(err, "failed to simulate tx"), app.trace)
}
    simRes := &sdk.SimulationResponse{
    GasInfo: gInfo,
    Result:  res,
}

bz, err := codec.ProtoMarshalJSON(simRes, app.interfaceRegistry)
    if err != nil {
    return queryResult(errorsmod.Wrap(err, "failed to JSON encode simulation response"), app.trace)
}

return &abci.QueryResponse{
    Codespace: sdkerrors.RootCodespace,
    Height:    req.Height,
    Value:     bz,
}
    case "version":
			return &abci.QueryResponse{
    Codespace: sdkerrors.RootCodespace,
    Height:    req.Height,
    Value:     []byte(app.version),
}

default:
			return queryResult(errorsmod.Wrapf(sdkerrors.ErrUnknownRequest, "unknown query: %s", path), app.trace)
}
	
}

return queryResult(
		errorsmod.Wrap(
			sdkerrors.ErrUnknownRequest,
			"expected second parameter to be either 'simulate' or 'version', neither was present",
		), app.trace)
}

func handleQueryStore(app *BaseApp, path []string, req abci.QueryRequest) *abci.QueryResponse {
	// "/store" prefix for store queries
	queryable, ok := app.cms.(storetypes.Queryable)
    if !ok {
    return queryResult(errorsmod.Wrap(sdkerrors.ErrUnknownRequest, "multi-store does not support queries"), app.trace)
}

req.Path = "/" + strings.Join(path[1:], "/")
    if req.Height <= 1 && req.Prove {
    return queryResult(
			errorsmod.Wrap(
				sdkerrors.ErrInvalidRequest,
				"cannot query with proof when height <= 1; please provide a valid height",
			), app.trace)
}
    sdkReq := storetypes.RequestQuery(req)

resp, err := queryable.Query(&sdkReq)
    if err != nil {
    return queryResult(err, app.trace)
}

resp.Height = req.Height
    abciResp := abci.QueryResponse(*resp)

return &abciResp
}

func handleQueryP2P(app *BaseApp, path []string) *abci.QueryResponse {
	// "/p2p" prefix for p2p queries
    if len(path) < 4 {
    return queryResult(errorsmod.Wrap(sdkerrors.ErrUnknownRequest, "path should be p2p filter <addr|id> <parameter>"), app.trace)
}

var resp *abci.QueryResponse

	cmd, typ, arg := path[1], path[2], path[3]
    switch cmd {
    case "filter":
    switch typ {
    case "addr":
			resp = app.FilterPeerByAddrPort(arg)
    case "id":
			resp = app.FilterPeerByID(arg)
}

default:
		resp = queryResult(errorsmod.Wrap(sdkerrors.ErrUnknownRequest, "expected second parameter to be 'filter'"), app.trace)
}

return resp
}

// SplitABCIQueryPath splits a string path using the delimiter '/'.
//
// e.g. "this/is/funny" becomes []string{"this", "is", "funny"}


func SplitABCIQueryPath(requestPath string) (path []string) {
    path = strings.Split(requestPath, "/")

	// first element is empty string
    if len(path) > 0 && path[0] == "" {
    path = path[1:]
}

return path
}

// FilterPeerByAddrPort filters peers by address/port.
func (app *BaseApp)

FilterPeerByAddrPort(info string) *abci.QueryResponse {
    if app.addrPeerFilter != nil {
    return app.addrPeerFilter(info)
}

return &abci.QueryResponse{
}
}

// FilterPeerByID filters peers by node ID.
func (app *BaseApp)

FilterPeerByID(info string) *abci.QueryResponse {
    if app.idPeerFilter != nil {
    return app.idPeerFilter(info)
}

return &abci.QueryResponse{
}
}

// getContextForProposal returns the correct Context for PrepareProposal and
// ProcessProposal. We use finalizeBlockState on the first block to be able to
// access any state changes made in InitChain.
func (app *BaseApp)

getContextForProposal(ctx sdk.Context, height int64)

sdk.Context {
    if height == app.initialHeight {
    ctx, _ = app.finalizeBlockState.Context().CacheContext()

		// clear all context data set during InitChain to avoid inconsistent behavior
		ctx = ctx.WithHeaderInfo(coreheader.Info{
}).WithBlockHeader(cmtproto.Header{
})

return ctx
}

return ctx
}

func (app *BaseApp)

handleQueryGRPC(handler GRPCQueryHandler, req *abci.QueryRequest) *abci.QueryResponse {
    ctx, err := app.CreateQueryContext(req.Height, req.Prove)
    if err != nil {
    return queryResult(err, app.trace)
}

resp, err := handler(ctx, req)
    if err != nil {
    resp = queryResult(gRPCErrorToSDKError(err), app.trace)

resp.Height = req.Height
		return resp
}

return resp
}

func gRPCErrorToSDKError(err error)

error {
    status, ok := grpcstatus.FromError(err)
    if !ok {
    return errorsmod.Wrap(sdkerrors.ErrInvalidRequest, err.Error())
}
    switch status.Code() {
    case codes.NotFound:
		return errorsmod.Wrap(sdkerrors.ErrKeyNotFound, err.Error())
    case codes.InvalidArgument:
		return errorsmod.Wrap(sdkerrors.ErrInvalidRequest, err.Error())
    case codes.FailedPrecondition:
		return errorsmod.Wrap(sdkerrors.ErrInvalidRequest, err.Error())
    case codes.Unauthenticated:
		return errorsmod.Wrap(sdkerrors.ErrUnauthorized, err.Error())

default:
		return errorsmod.Wrap(sdkerrors.ErrUnknownRequest, err.Error())
}
}

func checkNegativeHeight(height int64)

error {
    if height < 0 {
    return errorsmod.Wrap(sdkerrors.ErrInvalidRequest, "cannot query with height < 0; please provide a valid height")
}

return nil
}

// CreateQueryContext creates a new sdk.Context for a query, taking as args
// the block height and whether the query needs a proof or not.
func (app *BaseApp)

CreateQueryContext(height int64, prove bool) (sdk.Context, error) {
    if err := checkNegativeHeight(height); err != nil {
    return sdk.Context{
}, err
}

	// use custom query multi-store if provided
    qms := app.qms
    if qms == nil {
    qms = app.cms.(storetypes.MultiStore)
}
    lastBlockHeight := qms.LatestVersion()
    if lastBlockHeight == 0 {
    return sdk.Context{
}, errorsmod.Wrapf(sdkerrors.ErrInvalidHeight, "%s is not ready; please wait for first block", app.Name())
}
    if height > lastBlockHeight {
    return sdk.Context{
},
			errorsmod.Wrap(
				sdkerrors.ErrInvalidHeight,
				"cannot query with height in the future; please provide a valid height",
			)
}

	// when a client did not provide a query height, manually inject the latest
    if height == 0 {
    height = lastBlockHeight
}
    if height <= 1 && prove {
    return sdk.Context{
},
			errorsmod.Wrap(
				sdkerrors.ErrInvalidRequest,
				"cannot query with proof when height <= 1; please provide a valid height",
			)
}

cacheMS, err := qms.CacheMultiStoreWithVersion(height)
    if err != nil {
    return sdk.Context{
},
			errorsmod.Wrapf(
				sdkerrors.ErrNotFound,
				"failed to load state at height %d; %s (latest height: %d)", height, err, lastBlockHeight,
			)
}

	// branch the commit multi-store for safety
    ctx := sdk.NewContext(cacheMS, true, app.logger).
		WithMinGasPrices(app.minGasPrices).
		WithGasMeter(storetypes.NewGasMeter(app.queryGasLimit)).
		WithHeaderInfo(coreheader.Info{
    ChainID: app.chainID,
    Height:  height,
}).
		WithBlockHeader(app.checkState.Context().BlockHeader()).
		WithBlockHeight(height)
    if height != lastBlockHeight {
    rms, ok := app.cms.(*rootmulti.Store)
    if ok {
    cInfo, err := rms.GetCommitInfo(height)
    if cInfo != nil && err == nil {
    ctx = ctx.WithHeaderInfo(coreheader.Info{
    Height: height,
    Time: cInfo.Timestamp
})
}
	
}
	
}

return ctx, nil
}

// GetBlockRetentionHeight returns the height for which all blocks below this height
// are pruned from CometBFT. Given a commitment height and a non-zero local
// minRetainBlocks configuration, the retentionHeight is the smallest height that
// satisfies:
//
// - Unbonding (safety threshold)

time: The block interval in which validators
// can be economically punished for misbehavior. Blocks in this interval must be
// auditable e.g. by the light client.
//
// - Logical store snapshot interval: The block interval at which the underlying
// logical store database is persisted to disk, e.g. every 10000 heights. Blocks
// since the last IAVL snapshot must be available for replay on application restart.
//
// - State sync snapshots: Blocks since the oldest available snapshot must be
// available for state sync nodes to catch up (oldest because a node may be
// restoring an old snapshot while a new snapshot was taken).
//
// - Local (minRetainBlocks)

config: Archive nodes may want to retain more or
// all blocks, e.g. via a local config option min-retain-blocks. There may also
// be a need to vary retention for other nodes, e.g. sentry nodes which do not
// need historical blocks.
func (app *BaseApp)

GetBlockRetentionHeight(commitHeight int64)

int64 {
	// pruning is disabled if minRetainBlocks is zero
    if app.minRetainBlocks == 0 {
    return 0
}
    minNonZero := func(x, y int64)

int64 {
    switch {
    case x == 0:
			return y
    case y == 0:
			return x
    case x < y:
			return x

		default:
			return y
}
	
}

	// Define retentionHeight as the minimum value that satisfies all non-zero
	// constraints. All blocks below (commitHeight-retentionHeight)

are pruned
	// from CometBFT.
	var retentionHeight int64

	// Define the number of blocks needed to protect against misbehaving validators
	// which allows light clients to operate safely. Note, we piggyback on the
	// evidence parameters instead of computing an estimated number of blocks based
	// on the unbonding period and block commitment time as the two should be
	// equivalent.
    cp := app.GetConsensusParams(app.finalizeBlockState.Context())
    if cp.Evidence != nil && cp.Evidence.MaxAgeNumBlocks > 0 {
    retentionHeight = commitHeight - cp.Evidence.MaxAgeNumBlocks
}
    if app.snapshotManager != nil {
    snapshotRetentionHeights := app.snapshotManager.GetSnapshotBlockRetentionHeights()
    if snapshotRetentionHeights > 0 {
    retentionHeight = minNonZero(retentionHeight, commitHeight-snapshotRetentionHeights)
}
	
}
    v := commitHeight - int64(app.minRetainBlocks)

retentionHeight = minNonZero(retentionHeight, v)
    if retentionHeight <= 0 {
		// prune nothing in the case of a non-positive height
		return 0
}

return retentionHeight
}

// toVoteInfo converts the new ExtendedVoteInfo to VoteInfo.
func toVoteInfo(votes []abci.ExtendedVoteInfo) []abci.VoteInfo {
    legacyVotes := make([]abci.VoteInfo, len(votes))
    for i, vote := range votes {
    legacyVotes[i] = abci.VoteInfo{
    Validator: abci.Validator{
    Address: vote.Validator.Address,
    Power:   vote.Validator.Power,
},
    BlockIdFlag: vote.BlockIdFlag,
}
	
}

return legacyVotes
}
```

## CheckTx Handler

`CheckTxHandler` allows users to extend the logic of `CheckTx`. `CheckTxHandler` is called by passing context and the transaction bytes received through ABCI. It is required that the handler returns deterministic results given the same transaction bytes.

<Note>
  we return the raw decoded transaction here to avoid decoding it twice.
</Note>

```go theme={"theme":{"light":"github-light-high-contrast","dark":"github-dark-high-contrast"}}
type CheckTxHandler func(ctx sdk.Context, tx []byte) (Tx, error)
```

Setting a custom `CheckTxHandler` is optional. It can be done from your app.go file:

```go expandable theme={"theme":{"light":"github-light-high-contrast","dark":"github-dark-high-contrast"}}
func NewSimApp(
	logger log.Logger,
	db corestore.KVStoreWithBatch,
	traceStore io.Writer,
	loadLatest bool,
	appOpts servertypes.AppOptions,
	baseAppOptions ...func(*baseapp.BaseApp),
) *SimApp {
  ...
  // Create CheckTxHandler
    checktxHandler := abci.NewCustomCheckTxHandler(...)

app.SetCheckTxHandler(checktxHandler)
  ...
}
```