baseapp 实现了 cometBFT定义的接口：
type Application interface {
// Info/Query Connection
Info(RequestInfo) ResponseInfo // Return application info
Query(RequestQuery) ResponseQuery // Query for state
// Mempool Connection
CheckTx(RequestCheckTx) ResponseCheckTx // Validate a tx for the mempool
// Consensus Connection
InitChain(RequestInitChain) ResponseInitChain // Initialize blockchain w validators/other info from CometBFT
PrepareProposal(RequestPrepareProposal) ResponsePrepareProposal
ProcessProposal(RequestProcessProposal) ResponseProcessProposal
BeginBlock(RequestBeginBlock) ResponseBeginBlock // Signals the beginning of a block
DeliverTx(RequestDeliverTx) ResponseDeliverTx // Deliver a tx for full processing
EndBlock(RequestEndBlock) ResponseEndBlock // Signals the end of a block, returns changes to the validator set
Commit() ResponseCommit // Commit the state and return the application Merkle root hash
// State Sync Connection
ListSnapshots(RequestListSnapshots) ResponseListSnapshots // List available snapshots
OfferSnapshot(RequestOfferSnapshot) ResponseOfferSnapshot // Offer a snapshot to the application
LoadSnapshotChunk(RequestLoadSnapshotChunk) ResponseLoadSnapshotChunk // Load a snapshot chunk
ApplySnapshotChunk(RequestApplySnapshotChunk) ResponseApplySnapshotChunk // Apply a shapshot chunk
}baseapp的结构：
type BaseApp struct {
// initialized on creation
logger log.Logger
name string // application name from abci.BlockInfo
db dbm.DB // common DB backend
cms storetypes.CommitMultiStore // Main (uncached) state
qms storetypes.MultiStore // Optional alternative multistore for querying only.
storeLoader StoreLoader // function to handle store loading, may be overridden with SetStoreLoader()
grpcQueryRouter *GRPCQueryRouter // router for redirecting gRPC query calls
msgServiceRouter *MsgServiceRouter // router for redirecting Msg service messages
interfaceRegistry codectypes.InterfaceRegistry
txDecoder sdk.TxDecoder // unmarshal []byte into sdk.Tx
txEncoder sdk.TxEncoder // marshal sdk.Tx into []byte
mempool mempool.Mempool // application side mempool
anteHandler sdk.AnteHandler // ante handler for fee and auth
postHandler sdk.PostHandler // post handler, optional, e.g. for tips
initChainer sdk.InitChainer // initialize state with validators and state blob
beginBlocker sdk.BeginBlocker // logic to run before any txs
processProposal sdk.ProcessProposalHandler // the handler which runs on ABCI ProcessProposal
prepareProposal sdk.PrepareProposalHandler // the handler which runs on ABCI PrepareProposal
endBlocker sdk.EndBlocker // logic to run after all txs, and to determine valset changes
prepareCheckStater sdk.PrepareCheckStater // logic to run during commit using the checkState
precommiter sdk.Precommiter // logic to run during commit using the deliverState
addrPeerFilter sdk.PeerFilter // filter peers by address and port
idPeerFilter sdk.PeerFilter // filter peers by node ID
fauxMerkleMode bool // if true, IAVL MountStores uses MountStoresDB for simulation speed.
// manages snapshots, i.e. dumps of app state at certain intervals
snapshotManager *snapshots.Manager
// volatile states:
//
// checkState is set on InitChain and reset on Commit
// deliverState is set on InitChain and BeginBlock and set to nil on Commit
checkState *state // for CheckTx
deliverState *state // for DeliverTx
processProposalState *state // for ProcessProposal
prepareProposalState *state // for PrepareProposal
// an inter-block write-through cache provided to the context during deliverState
interBlockCache storetypes.MultiStorePersistentCache
// paramStore is used to query for ABCI consensus parameters from an
// application parameter store.
paramStore ParamStore
// The minimum gas prices a validator is willing to accept for processing a
// transaction. This is mainly used for DoS and spam prevention.
minGasPrices sdk.DecCoins
// initialHeight is the initial height at which we start the baseapp
initialHeight int64
// flag for sealing options and parameters to a BaseApp
sealed bool
// block height at which to halt the chain and gracefully shutdown
haltHeight uint64
// minimum block time (in Unix seconds) at which to halt the chain and gracefully shutdown
haltTime uint64
// minRetainBlocks defines the minimum block height offset from the current
// block being committed, such that all blocks past this offset are pruned
// from CometBFT. It is used as part of the process of determining the
// ResponseCommit.RetainHeight value during ABCI Commit. A value of 0 indicates
// that no blocks should be pruned.
//
// Note: CometBFT block pruning is dependant on this parameter in conjunction
// with the unbonding (safety threshold) period, state pruning and state sync
// snapshot parameters to determine the correct minimum value of
// ResponseCommit.RetainHeight.
minRetainBlocks uint64
// application's version string
version string
// application's protocol version that increments on every upgrade
// if BaseApp is passed to the upgrade keeper's NewKeeper method.
appVersion uint64
// recovery handler for app.runTx method
runTxRecoveryMiddleware recoveryMiddleware
// trace set will return full stack traces for errors in ABCI Log field
trace bool
// indexEvents defines the set of events in the form {eventType}.{attributeKey},
// which informs CometBFT what to index. If empty, all events will be indexed.
indexEvents map[string]struct{}
// streamingManager for managing instances and configuration of ABCIListener services
streamingManager storetypes.StreamingManager
chainID string
}