Skip signature event building during Cosmos CheckTx/ReCheckTx

app/ante/cosmos_checktx.go

@@ -400,17 +400,22 @@ func CheckSignatures(ctx sdk.Context, txConfig client.TxConfig, tx sdk.Tx, signe
 		return nil, sdkerrors.Wrapf(sdkerrors.ErrUnauthorized, "invalid number of signer;  expected: %d, got %d", len(signerAddrs), len(sigs))
 	}
 	var events sdk.Events
+	// CheckTx and ReCheckTx discard these events (see CosmosCheckTxAnte); building them
+	// still runs SignatureDataToBz + base64 per signer — measurable CPU/alloc on hot path.
+	skipSigEvents := ctx.IsCheckTx() || ctx.IsReCheckTx()
 	for i, sig := range sigs {
-		events = append(events, sdk.NewEvent(sdk.EventTypeTx,
-			sdk.NewAttribute(sdk.AttributeKeyAccountSequence, fmt.Sprintf("%s/%d", signerAddrs[i], sig.Sequence)),
-		))
-		if sigBzs, err := authante.SignatureDataToBz(sig.Data); err != nil {
-			return nil, err
-		} else {
-			for _, sigBz := range sigBzs {
-				events = append(events, sdk.NewEvent(sdk.EventTypeTx,
-					sdk.NewAttribute(sdk.AttributeKeySignature, base64.StdEncoding.EncodeToString(sigBz)),
-				))
+		if !skipSigEvents {
+			events = append(events, sdk.NewEvent(sdk.EventTypeTx,
+				sdk.NewAttribute(sdk.AttributeKeyAccountSequence, fmt.Sprintf("%s/%d", signerAddrs[i], sig.Sequence)),
+			))
+			if sigBzs, err := authante.SignatureDataToBz(sig.Data); err != nil {
+				return nil, err
+			} else {
+				for _, sigBz := range sigBzs {
+					events = append(events, sdk.NewEvent(sdk.EventTypeTx,
+						sdk.NewAttribute(sdk.AttributeKeySignature, base64.StdEncoding.EncodeToString(sigBz)),
+					))
+				}
 			}
 		}
 

app/cosmos_checktx_test.go

@@ -0,0 +1,82 @@
+package app_test
+
+import (
+	"testing"
+	"time"
+
+	"github.com/sei-protocol/sei-chain/app"
+	anteante "github.com/sei-protocol/sei-chain/app/ante"
+	"github.com/sei-protocol/sei-chain/sei-cosmos/client/tx"
+	"github.com/sei-protocol/sei-chain/sei-cosmos/testutil/testdata"
+	sdk "github.com/sei-protocol/sei-chain/sei-cosmos/types"
+	"github.com/sei-protocol/sei-chain/sei-cosmos/types/tx/signing"
+	authsigning "github.com/sei-protocol/sei-chain/sei-cosmos/x/auth/signing"
+	authtypes "github.com/sei-protocol/sei-chain/sei-cosmos/x/auth/types"
+	tmproto "github.com/sei-protocol/sei-chain/sei-tendermint/proto/tendermint/types"
+	"github.com/stretchr/testify/require"
+)
+
+// TestCheckSignaturesSkipsEventsOnCheckTx verifies that signature events
+// (account sequence + signature bytes) are not built during CheckTx or
+// ReCheckTx, but are built during DeliverTx.
+func TestCheckSignaturesSkipsEventsOnCheckTx(t *testing.T) {
+	testApp := app.Setup(t, false, false, false)
+	ctx := testApp.NewContext(false, tmproto.Header{Height: 1, ChainID: "sei-test", Time: time.Now().UTC()})
+
+	encodingConfig := app.MakeEncodingConfig()
+	txConfig := encodingConfig.TxConfig
+
+	privKey, pubKey, addr := testdata.KeyTestPubAddr()
+
+	acc := authtypes.NewBaseAccount(addr, pubKey, 0, 0)
+	signerAccounts := []authtypes.AccountI{acc}
+	authParams := authtypes.DefaultParams()
+
+	// Build and sign a tx.
+	txBuilder := txConfig.NewTxBuilder()
+	err := txBuilder.SetMsgs(testdata.NewTestMsg(addr))
+	require.NoError(t, err)
+	txBuilder.SetFeeAmount(testdata.NewTestFeeAmount())
+	txBuilder.SetGasLimit(testdata.NewTestGasLimit())
+
+	// First pass: set empty sigs so signer info is populated.
+	sigsV2 := []signing.SignatureV2{{
+		PubKey: pubKey,
+		Data: &signing.SingleSignatureData{
+			SignMode:  txConfig.SignModeHandler().DefaultMode(),
+			Signature: nil,
+		},
+		Sequence: 0,
+	}}
+	require.NoError(t, txBuilder.SetSignatures(sigsV2...))
+
+	// Second pass: real signature.
+	signerData := authsigning.SignerData{ChainID: "sei-test", AccountNumber: 0, Sequence: 0}
+	sigV2, err := tx.SignWithPrivKey(txConfig.SignModeHandler().DefaultMode(), signerData, txBuilder, privKey, txConfig, 0)
+	require.NoError(t, err)
+	require.NoError(t, txBuilder.SetSignatures(sigV2))
+
+	signedTx := txBuilder.GetTx()
+
+	// Use an infinite gas meter so signature verification gas consumption doesn't
+	// cause a panic when the context has no real store behind it.
+	gasCtx := ctx.WithGasMeter(sdk.NewInfiniteGasMeter(1, 1))
+
+	// DeliverTx context: both flags false → events must be populated.
+	deliverCtx := gasCtx.WithIsCheckTx(false)
+	events, err := anteante.CheckSignatures(deliverCtx, txConfig, signedTx, signerAccounts, authParams)
+	require.NoError(t, err)
+	require.NotEmpty(t, events, "expected signature events in DeliverTx context")
+
+	// CheckTx context → events must be empty.
+	checkCtx := gasCtx.WithIsCheckTx(true)
+	events, err = anteante.CheckSignatures(checkCtx, txConfig, signedTx, signerAccounts, authParams)
+	require.NoError(t, err)
+	require.Empty(t, events, "expected no signature events in CheckTx context")
+
+	// ReCheckTx context → events must be empty.
+	recheckCtx := gasCtx.WithIsCheckTx(false).WithIsReCheckTx(true)
+	events, err = anteante.CheckSignatures(recheckCtx, txConfig, signedTx, signerAccounts, authParams)
+	require.NoError(t, err)
+	require.Empty(t, events, "expected no signature events in ReCheckTx context")
+}