diff --git a/executor/batch/batch.go b/executor/batch/batch.go
index a1c6b43..79b4587 100644
--- a/executor/batch/batch.go
+++ b/executor/batch/batch.go
@@ -13,7 +13,6 @@ import (
 	opchildtypes "github.com/initia-labs/OPinit/x/opchild/types"
 	ophosttypes "github.com/initia-labs/OPinit/x/ophost/types"
 	executortypes "github.com/initia-labs/opinit-bots-go/executor/types"
-	"github.com/initia-labs/opinit-bots-go/merkle"
 	nodetypes "github.com/initia-labs/opinit-bots-go/node/types"
 	"github.com/initia-labs/opinit-bots-go/types"
 	"go.uber.org/zap"
@@ -44,7 +43,6 @@ type BatchSubmitter struct {
 	node *node.Node
 	host hostNode
 	da   executortypes.DANode
-	mk   *merkle.Merkle
 
 	bridgeInfo opchildtypes.BridgeInfo
 
@@ -115,7 +113,7 @@ func (bs *BatchSubmitter) Initialize(host hostNode, da executortypes.DANode, bri
 		if len(bs.batchInfos) == 1 || batchInfo.Output.L2BlockNumber >= bs.node.GetHeight() {
 			break
 		}
-		bs.PopBatchInfo()
+		bs.DequeueBatchInfo()
 	}
 	// TODO: set da and  key that match the current batch info
 	bs.da = da
diff --git a/executor/batch/handler.go b/executor/batch/handler.go
index baa1236..c05438b 100644
--- a/executor/batch/handler.go
+++ b/executor/batch/handler.go
@@ -9,6 +9,8 @@ import (
 	"io"
 	"time"
 
+	"github.com/pkg/errors"
+
 	sdk "github.com/cosmos/cosmos-sdk/types"
 	executortypes "github.com/initia-labs/opinit-bots-go/executor/types"
 	nodetypes "github.com/initia-labs/opinit-bots-go/node/types"
@@ -27,92 +29,115 @@ func (bs *BatchSubmitter) rawBlockHandler(args nodetypes.RawBlockArgs) error {
 	pbb := new(cmtproto.Block)
 	err := proto.Unmarshal(args.BlockBytes, pbb)
 	if err != nil {
-		return err
+		return errors.Wrap(err, "failed to unmarshal block")
 	}
 
 	err = bs.prepareBatch(args.BlockHeight, pbb.Header.Time)
 	if err != nil {
-		return err
+		return errors.Wrap(err, "failed to prepare batch")
 	}
+
 	err = bs.handleBatch(args.BlockBytes)
 	if err != nil {
-		return err
+		return errors.Wrap(err, "failed to handle batch")
 	}
 
 	err = bs.checkBatch(args.BlockHeight, pbb.Header.Time)
 	if err != nil {
-		return err
+		return errors.Wrap(err, "failed to check batch")
 	}
 
+	// store the processed state into db with batch operation
 	batchKVs := make([]types.RawKV, 0)
 	batchKVs = append(batchKVs, bs.node.SyncInfoToRawKV(args.BlockHeight))
-	batchMsgkvs, err := bs.da.ProcessedMsgsToRawKV(bs.processedMsgs, false)
+	batchMsgKVs, err := bs.da.ProcessedMsgsToRawKV(bs.processedMsgs, false)
 	if err != nil {
-		return err
+		return errors.Wrap(err, "failed to convert processed messages to raw key value")
 	}
-	batchKVs = append(batchKVs, batchMsgkvs...)
-	if len(batchMsgkvs) > 0 {
+	batchKVs = append(batchKVs, batchMsgKVs...)
+	if len(batchMsgKVs) > 0 {
 		batchKVs = append(batchKVs, bs.SubmissionInfoToRawKV(pbb.Header.Time.UnixNano()))
 	}
 	err = bs.db.RawBatchSet(batchKVs...)
 	if err != nil {
-		return err
+		return errors.Wrap(err, "failed to set raw batch")
 	}
+
+	// broadcast processed messages
 	for _, processedMsg := range bs.processedMsgs {
 		bs.da.BroadcastMsgs(processedMsg)
 	}
+
+	// clear processed messages
 	bs.processedMsgs = bs.processedMsgs[:0]
+
 	return nil
 }
 
 func (bs *BatchSubmitter) prepareBatch(blockHeight uint64, blockTime time.Time) error {
+
+	// check whether the requested block height is reached to the l2 block number of the next batch info.
 	if nextBatchInfo := bs.NextBatchInfo(); nextBatchInfo != nil && nextBatchInfo.Output.L2BlockNumber < blockHeight {
+
+		// if the next batch info is reached, finalize the current batch and update the batch info.
 		if bs.batchWriter != nil {
 			err := bs.batchWriter.Close()
 			if err != nil {
-				return err
+				return errors.Wrap(err, "failed to close batch writer")
 			}
 		}
 		err := bs.batchFile.Truncate(0)
 		if err != nil {
-			return err
+			return errors.Wrap(err, "failed to truncate batch file")
 		}
 		_, err = bs.batchFile.Seek(0, 0)
 		if err != nil {
-			return err
+			return errors.Wrap(err, "failed to seek batch file")
 		}
+
+		// save sync info
 		err = bs.node.SaveSyncInfo(nextBatchInfo.Output.L2BlockNumber)
 		if err != nil {
-			return err
+			return errors.Wrap(err, "failed to save sync info")
 		}
+
 		// set last processed block height to l2 block number
 		bs.node.SetSyncInfo(nextBatchInfo.Output.L2BlockNumber)
-		bs.PopBatchInfo()
+		bs.DequeueBatchInfo()
 
 		// error will restart block process from nextBatchInfo.Output.L2BlockNumber + 1
 		return fmt.Errorf("batch info updated: reset from %d", nextBatchInfo.Output.L2BlockNumber)
 	}
 
 	if bs.batchHeader != nil {
+		// if the batch header end is not set, it means the batch is not finalized yet.
 		if bs.batchHeader.End == 0 {
 			return nil
 		}
+
 		err := bs.finalizeBatch(blockHeight)
 		if err != nil {
-			return err
+			return errors.Wrap(err, "failed to finalize batch")
 		}
+
+		// update last submission time
 		bs.lastSubmissionTime = blockTime
 	}
-	bs.batchHeader = &executortypes.BatchHeader{}
+
+	// reset batch header
 	var err error
+	bs.batchHeader = &executortypes.BatchHeader{}
+
 	// linux command gzip use level 6 as default
 	bs.batchWriter, err = gzip.NewWriterLevel(bs.batchFile, 6)
 	if err != nil {
 		return err
 	}
+
 	return nil
 }
 
+// write block bytes to batch file
 func (bs *BatchSubmitter) handleBatch(blockBytes []byte) error {
 	encodedBlockBytes := base64.StdEncoding.EncodeToString(blockBytes)
 	_, err := bs.batchWriter.Write(append([]byte(encodedBlockBytes), ','))
@@ -122,23 +147,27 @@ func (bs *BatchSubmitter) handleBatch(blockBytes []byte) error {
 	return nil
 }
 
+// finalize batch and create batch messages
 func (bs *BatchSubmitter) finalizeBatch(blockHeight uint64) error {
+
+	// write last block's commit to batch file
 	rawCommit, err := bs.node.QueryRawCommit(int64(blockHeight))
 	if err != nil {
-		return err
+		return errors.Wrap(err, "failed to query raw commit")
 	}
 	encodedRawCommit := base64.StdEncoding.EncodeToString(rawCommit)
 	_, err = bs.batchWriter.Write([]byte(encodedRawCommit))
 	if err != nil {
-		return err
+		return errors.Wrap(err, "failed to write raw commit")
 	}
 	err = bs.batchWriter.Close()
 	if err != nil {
-		return err
+		return errors.Wrap(err, "failed to close batch writer")
 	}
 
 	batchBuffer := make([]byte, bs.batchCfg.MaxChunkSize)
 	checksums := make([][]byte, 0)
+
 	// room for batch header
 	bs.processedMsgs = append(bs.processedMsgs, nodetypes.ProcessedMsgs{
 		Timestamp: time.Now().UnixNano(),
@@ -152,7 +181,9 @@ func (bs *BatchSubmitter) finalizeBatch(blockHeight uint64) error {
 		} else if readLength == 0 {
 			break
 		}
-		batchBuffer = batchBuffer[:readLength]
+
+		// trim the buffer to the actual read length
+		batchBuffer := batchBuffer[:readLength]
 		msg, err := bs.createBatchMsg(batchBuffer)
 		if err != nil {
 			return err
@@ -168,6 +199,8 @@ func (bs *BatchSubmitter) finalizeBatch(blockHeight uint64) error {
 			break
 		}
 	}
+
+	// update batch header
 	bs.batchHeader.Chunks = checksums
 	headerBytes, err := json.Marshal(bs.batchHeader)
 	if err != nil {
@@ -178,6 +211,8 @@ func (bs *BatchSubmitter) finalizeBatch(blockHeight uint64) error {
 		return err
 	}
 	bs.processedMsgs[0].Msgs = []sdk.Msg{msg}
+
+	// reset batch file
 	err = bs.batchFile.Truncate(0)
 	if err != nil {
 		return err
@@ -186,23 +221,32 @@ func (bs *BatchSubmitter) finalizeBatch(blockHeight uint64) error {
 	if err != nil {
 		return err
 	}
+
 	return nil
 }
 
 func (bs *BatchSubmitter) checkBatch(blockHeight uint64, blockTime time.Time) error {
 	info, err := bs.batchFile.Stat()
 	if err != nil {
-		return err
+		return errors.Wrap(err, "failed to get batch file stat")
 	}
 
+	// if the block time is after the last submission time + submission interval * 2/3
+	// or the block time is after the last submission time + max submission time
+	// or the batch file size is greater than (max chunks - 1) * max chunk size
+	// then finalize the batch
 	if blockTime.After(bs.lastSubmissionTime.Add(bs.bridgeInfo.BridgeConfig.SubmissionInterval*2/3)) ||
 		blockTime.After(bs.lastSubmissionTime.Add(time.Duration(bs.batchCfg.MaxSubmissionTime)*time.Second)) ||
 		info.Size() > (bs.batchCfg.MaxChunks-1)*bs.batchCfg.MaxChunkSize {
+
+		// finalize the batch
 		bs.batchHeader.End = blockHeight
 	}
+
 	return nil
 }
 
+// TODO: support celestia
 func (bs *BatchSubmitter) createBatchMsg(batchBytes []byte) (sdk.Msg, error) {
 	submitter, err := bs.da.GetAddressStr()
 	if err != nil {
@@ -216,6 +260,7 @@ func (bs *BatchSubmitter) createBatchMsg(batchBytes []byte) (sdk.Msg, error) {
 	), nil
 }
 
+// UpdateBatchInfo appends the batch info with the given chain, submitter, output index, and l2 block number
 func (bs *BatchSubmitter) UpdateBatchInfo(chain string, submitter string, outputIndex uint64, l2BlockNumber uint64) {
 	bs.batchInfoMu.Lock()
 	defer bs.batchInfoMu.Unlock()
@@ -231,6 +276,7 @@ func (bs *BatchSubmitter) UpdateBatchInfo(chain string, submitter string, output
 	})
 }
 
+// BatchInfo returns the current batch info
 func (bs *BatchSubmitter) BatchInfo() *ophosttypes.BatchInfoWithOutput {
 	bs.batchInfoMu.Lock()
 	defer bs.batchInfoMu.Unlock()
@@ -238,6 +284,7 @@ func (bs *BatchSubmitter) BatchInfo() *ophosttypes.BatchInfoWithOutput {
 	return &bs.batchInfos[0]
 }
 
+// NextBatchInfo returns the next batch info in the queue
 func (bs *BatchSubmitter) NextBatchInfo() *ophosttypes.BatchInfoWithOutput {
 	bs.batchInfoMu.Lock()
 	defer bs.batchInfoMu.Unlock()
@@ -247,7 +294,8 @@ func (bs *BatchSubmitter) NextBatchInfo() *ophosttypes.BatchInfoWithOutput {
 	return &bs.batchInfos[1]
 }
 
-func (bs *BatchSubmitter) PopBatchInfo() {
+// DequeueBatchInfo removes the first batch info from the queue
+func (bs *BatchSubmitter) DequeueBatchInfo() {
 	bs.batchInfoMu.Lock()
 	defer bs.batchInfoMu.Unlock()
 
diff --git a/executor/executor.go b/executor/executor.go
index 1b3546a..5ad3265 100644
--- a/executor/executor.go
+++ b/executor/executor.go
@@ -53,7 +53,11 @@ func NewExecutor(cfg *executortypes.Config, db types.DB, sv *server.Server, logg
 			db.WithPrefix([]byte(executortypes.ChildNodeName)),
 			logger.Named(executortypes.ChildNodeName), cdc, txConfig,
 		),
-		batch: batch.NewBatchSubmitter(cfg.Version, cfg.DANodeConfig(), cfg.BatchConfig(), db.WithPrefix([]byte(executortypes.BatchNodeName)), logger.Named(executortypes.BatchNodeName), cdc, txConfig, homePath),
+		batch: batch.NewBatchSubmitter(
+			cfg.Version, cfg.DANodeConfig(), cfg.BatchConfig(),
+			db.WithPrefix([]byte(executortypes.BatchNodeName)),
+			logger.Named(executortypes.BatchNodeName), cdc, txConfig, homePath,
+		),
 
 		cfg:    cfg,
 		db:     db,
diff --git a/executor/types/batch.go b/executor/types/batch.go
index 56bf815..9ea92ed 100644
--- a/executor/types/batch.go
+++ b/executor/types/batch.go
@@ -9,7 +9,7 @@ type DANode interface {
 	GetAddressStr() (string, error)
 	HasKey() bool
 	BroadcastMsgs(nodetypes.ProcessedMsgs)
-	ProcessedMsgsToRawKV([]nodetypes.ProcessedMsgs, bool) ([]types.RawKV, error)
+	ProcessedMsgsToRawKV(processedMsgs []nodetypes.ProcessedMsgs, delete bool) ([]types.RawKV, error)
 }
 
 type BatchHeader struct {
diff --git a/executor/types/config.go b/executor/types/config.go
index 2dceffb..ae67e76 100644
--- a/executor/types/config.go
+++ b/executor/types/config.go
@@ -46,8 +46,11 @@ type Config struct {
 	// RelayOracle is the flag to enable the oracle relay feature.
 	RelayOracle bool `json:"relay_oracle"`
 
-	MaxChunks         int64 `json:"max_chunks"`
-	MaxChunkSize      int64 `json:"max_chunk_size"`
+	// MaxChunks is the maximum number of chunks in a batch.
+	MaxChunks int64 `json:"max_chunks"`
+	// MaxChunkSize is the maximum size of a chunk in a batch.
+	MaxChunkSize int64 `json:"max_chunk_size"`
+	// MaxSubmissionTime is the maximum time to submit a batch.
 	MaxSubmissionTime int64 `json:"max_submission_time"` // seconds
 }
 
diff --git a/go.mod b/go.mod
index c9be55b..29ed031 100644
--- a/go.mod
+++ b/go.mod
@@ -178,7 +178,7 @@ require (
 	github.com/oasisprotocol/curve25519-voi v0.0.0-20230904125328-1f23a7beb09a // indirect
 	github.com/pelletier/go-toml/v2 v2.2.2 // indirect
 	github.com/petermattis/goid v0.0.0-20231207134359-e60b3f734c67 // indirect
-	github.com/pkg/errors v0.9.1 // indirect
+	github.com/pkg/errors v0.9.1
 	github.com/pmezard/go-difflib v1.0.1-0.20181226105442-5d4384ee4fb2 // indirect
 	github.com/prometheus/client_golang v1.19.0 // indirect
 	github.com/prometheus/client_model v0.6.1 // indirect
diff --git a/node/query.go b/node/query.go
index 0e1244e..b00996a 100644
--- a/node/query.go
+++ b/node/query.go
@@ -153,12 +153,14 @@ func GetQueryContext(height uint64) (context.Context, context.CancelFunc) {
 	return ctx, cancel
 }
 
+// QueryRawCommit queries the raw commit at a given height.
 func (n *Node) QueryRawCommit(height int64) ([]byte, error) {
 	ctx, cancel := GetQueryContext(uint64(height))
 	defer cancel()
 	return n.RawCommit(ctx, &height)
 }
 
+// QueryBlockBulk queries blocks in bulk.
 func (n *Node) QueryBlockBulk(start uint64, end uint64) ([][]byte, error) {
 	ctx, cancel := GetQueryContext(0)
 	defer cancel()
diff --git a/node/tx.go b/node/tx.go
index 9779101..9d031e3 100644
--- a/node/tx.go
+++ b/node/tx.go
@@ -9,6 +9,8 @@ import (
 	"strings"
 	"time"
 
+	"github.com/pkg/errors"
+
 	sdkerrors "cosmossdk.io/errors"
 	abci "github.com/cometbft/cometbft/abci/types"
 	comettypes "github.com/cometbft/cometbft/types"
@@ -55,7 +57,7 @@ func (n *Node) txBroadcastLooper(ctx context.Context) error {
 			}
 
 			if err != nil {
-				panic(err)
+				return errors.Wrap(err, "failed to handle processed msgs")
 			}
 		}
 	}