From 94d6cee64a0694a78911f0cf74d66ab6616f2561 Mon Sep 17 00:00:00 2001
From: DimitrisJim <d.f.hilliard@gmail.com>
Date: Wed, 5 Jun 2024 14:41:19 +0300
Subject: [PATCH 1/4] feat(transfer): move denom trace to internal folder.

---
 .../transfer/internal/types/denomtrace.pb.go  | 376 ++++++++++++++++++
 .../{ => internal}/types/legacy_denomtrace.go |   9 +-
 .../internal/types/legacy_denomtrace_test.go  |  27 ++
 modules/apps/transfer/keeper/export_test.go   |  11 +-
 modules/apps/transfer/keeper/migrations.go    |  17 +-
 .../apps/transfer/keeper/migrations_test.go   |  39 +-
 modules/apps/transfer/keeper/relay_test.go    |   9 +-
 modules/apps/transfer/simulation/decoder.go   |   3 +-
 .../apps/transfer/simulation/decoder_test.go  |   3 +-
 .../types/legacy_denomtrace_responses.go      |   8 +
 .../transfer/types/legacy_denomtrace_test.go  |  27 --
 modules/apps/transfer/types/transfer.pb.go    | 260 +-----------
 .../applications/transfer/v1/denomtrace.proto |  15 +
 .../applications/transfer/v1/transfer.proto   |  10 -
 scripts/protocgen.sh                          |   3 +
 15 files changed, 491 insertions(+), 326 deletions(-)
 create mode 100644 modules/apps/transfer/internal/types/denomtrace.pb.go
 rename modules/apps/transfer/{ => internal}/types/legacy_denomtrace.go (79%)
 create mode 100644 modules/apps/transfer/internal/types/legacy_denomtrace_test.go
 create mode 100644 modules/apps/transfer/types/legacy_denomtrace_responses.go
 delete mode 100644 modules/apps/transfer/types/legacy_denomtrace_test.go
 create mode 100644 proto/ibc/applications/transfer/v1/denomtrace.proto

diff --git a/modules/apps/transfer/internal/types/denomtrace.pb.go b/modules/apps/transfer/internal/types/denomtrace.pb.go
new file mode 100644
index 00000000000..4aed671f205
--- /dev/null
+++ b/modules/apps/transfer/internal/types/denomtrace.pb.go
@@ -0,0 +1,376 @@
+// Code generated by protoc-gen-gogo. DO NOT EDIT.
+// source: ibc/applications/transfer/v1/denomtrace.proto
+
+package types
+
+import (
+	fmt "fmt"
+	proto "github.com/cosmos/gogoproto/proto"
+	io "io"
+	math "math"
+	math_bits "math/bits"
+)
+
+// Reference imports to suppress errors if they are not otherwise used.
+var _ = proto.Marshal
+var _ = fmt.Errorf
+var _ = math.Inf
+
+// This is a compile-time assertion to ensure that this generated file
+// is compatible with the proto package it is being compiled against.
+// A compilation error at this line likely means your copy of the
+// proto package needs to be updated.
+const _ = proto.GoGoProtoPackageIsVersion3 // please upgrade the proto package
+
+// DenomTrace contains the base denomination for ICS20 fungible tokens and the
+// source tracing information path.
+type DenomTrace struct {
+	// path defines the chain of port/channel identifiers used for tracing the
+	// source of the fungible token.
+	Path string `protobuf:"bytes,1,opt,name=path,proto3" json:"path,omitempty"`
+	// base denomination of the relayed fungible token.
+	BaseDenom string `protobuf:"bytes,2,opt,name=base_denom,json=baseDenom,proto3" json:"base_denom,omitempty"`
+}
+
+func (m *DenomTrace) Reset()         { *m = DenomTrace{} }
+func (m *DenomTrace) String() string { return proto.CompactTextString(m) }
+func (*DenomTrace) ProtoMessage()    {}
+func (*DenomTrace) Descriptor() ([]byte, []int) {
+	return fileDescriptor_c400148599bf8bc8, []int{0}
+}
+func (m *DenomTrace) XXX_Unmarshal(b []byte) error {
+	return m.Unmarshal(b)
+}
+func (m *DenomTrace) XXX_Marshal(b []byte, deterministic bool) ([]byte, error) {
+	if deterministic {
+		return xxx_messageInfo_DenomTrace.Marshal(b, m, deterministic)
+	} else {
+		b = b[:cap(b)]
+		n, err := m.MarshalToSizedBuffer(b)
+		if err != nil {
+			return nil, err
+		}
+		return b[:n], nil
+	}
+}
+func (m *DenomTrace) XXX_Merge(src proto.Message) {
+	xxx_messageInfo_DenomTrace.Merge(m, src)
+}
+func (m *DenomTrace) XXX_Size() int {
+	return m.Size()
+}
+func (m *DenomTrace) XXX_DiscardUnknown() {
+	xxx_messageInfo_DenomTrace.DiscardUnknown(m)
+}
+
+var xxx_messageInfo_DenomTrace proto.InternalMessageInfo
+
+func (m *DenomTrace) GetPath() string {
+	if m != nil {
+		return m.Path
+	}
+	return ""
+}
+
+func (m *DenomTrace) GetBaseDenom() string {
+	if m != nil {
+		return m.BaseDenom
+	}
+	return ""
+}
+
+func init() {
+	proto.RegisterType((*DenomTrace)(nil), "ibc.applications.transfer.v1.DenomTrace")
+}
+
+func init() {
+	proto.RegisterFile("ibc/applications/transfer/v1/denomtrace.proto", fileDescriptor_c400148599bf8bc8)
+}
+
+var fileDescriptor_c400148599bf8bc8 = []byte{
+	// 211 bytes of a gzipped FileDescriptorProto
+	0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0xff, 0xe2, 0xd2, 0xcd, 0x4c, 0x4a, 0xd6,
+	0x4f, 0x2c, 0x28, 0xc8, 0xc9, 0x4c, 0x4e, 0x2c, 0xc9, 0xcc, 0xcf, 0x2b, 0xd6, 0x2f, 0x29, 0x4a,
+	0xcc, 0x2b, 0x4e, 0x4b, 0x2d, 0xd2, 0x2f, 0x33, 0xd4, 0x4f, 0x49, 0xcd, 0xcb, 0xcf, 0x2d, 0x29,
+	0x4a, 0x4c, 0x4e, 0xd5, 0x2b, 0x28, 0xca, 0x2f, 0xc9, 0x17, 0x92, 0xc9, 0x4c, 0x4a, 0xd6, 0x43,
+	0x56, 0xae, 0x07, 0x53, 0xae, 0x57, 0x66, 0xa8, 0x64, 0xcf, 0xc5, 0xe5, 0x02, 0xd2, 0x11, 0x02,
+	0xd2, 0x21, 0x24, 0xc4, 0xc5, 0x52, 0x90, 0x58, 0x92, 0x21, 0xc1, 0xa8, 0xc0, 0xa8, 0xc1, 0x19,
+	0x04, 0x66, 0x0b, 0xc9, 0x72, 0x71, 0x25, 0x25, 0x16, 0xa7, 0xc6, 0x83, 0x0d, 0x96, 0x60, 0x02,
+	0xcb, 0x70, 0x82, 0x44, 0xc0, 0xfa, 0x9c, 0x02, 0x4f, 0x3c, 0x92, 0x63, 0xbc, 0xf0, 0x48, 0x8e,
+	0xf1, 0xc1, 0x23, 0x39, 0xc6, 0x09, 0x8f, 0xe5, 0x18, 0x2e, 0x3c, 0x96, 0x63, 0xb8, 0xf1, 0x58,
+	0x8e, 0x21, 0xca, 0x3c, 0x3d, 0xb3, 0x24, 0xa3, 0x34, 0x49, 0x2f, 0x39, 0x3f, 0x57, 0x3f, 0x39,
+	0xbf, 0x38, 0x37, 0xbf, 0x58, 0x3f, 0x33, 0x29, 0x59, 0x37, 0x3d, 0x5f, 0xbf, 0xcc, 0x42, 0x3f,
+	0x37, 0x3f, 0xa5, 0x34, 0x27, 0xb5, 0x18, 0xe4, 0x0f, 0x24, 0xf7, 0x97, 0x54, 0x16, 0xa4, 0x16,
+	0x27, 0xb1, 0x81, 0x1d, 0x6e, 0x0c, 0x08, 0x00, 0x00, 0xff, 0xff, 0xa6, 0xd5, 0xd9, 0xdc, 0xe9,
+	0x00, 0x00, 0x00,
+}
+
+func (m *DenomTrace) Marshal() (dAtA []byte, err error) {
+	size := m.Size()
+	dAtA = make([]byte, size)
+	n, err := m.MarshalToSizedBuffer(dAtA[:size])
+	if err != nil {
+		return nil, err
+	}
+	return dAtA[:n], nil
+}
+
+func (m *DenomTrace) MarshalTo(dAtA []byte) (int, error) {
+	size := m.Size()
+	return m.MarshalToSizedBuffer(dAtA[:size])
+}
+
+func (m *DenomTrace) MarshalToSizedBuffer(dAtA []byte) (int, error) {
+	i := len(dAtA)
+	_ = i
+	var l int
+	_ = l
+	if len(m.BaseDenom) > 0 {
+		i -= len(m.BaseDenom)
+		copy(dAtA[i:], m.BaseDenom)
+		i = encodeVarintDenomtrace(dAtA, i, uint64(len(m.BaseDenom)))
+		i--
+		dAtA[i] = 0x12
+	}
+	if len(m.Path) > 0 {
+		i -= len(m.Path)
+		copy(dAtA[i:], m.Path)
+		i = encodeVarintDenomtrace(dAtA, i, uint64(len(m.Path)))
+		i--
+		dAtA[i] = 0xa
+	}
+	return len(dAtA) - i, nil
+}
+
+func encodeVarintDenomtrace(dAtA []byte, offset int, v uint64) int {
+	offset -= sovDenomtrace(v)
+	base := offset
+	for v >= 1<<7 {
+		dAtA[offset] = uint8(v&0x7f | 0x80)
+		v >>= 7
+		offset++
+	}
+	dAtA[offset] = uint8(v)
+	return base
+}
+func (m *DenomTrace) Size() (n int) {
+	if m == nil {
+		return 0
+	}
+	var l int
+	_ = l
+	l = len(m.Path)
+	if l > 0 {
+		n += 1 + l + sovDenomtrace(uint64(l))
+	}
+	l = len(m.BaseDenom)
+	if l > 0 {
+		n += 1 + l + sovDenomtrace(uint64(l))
+	}
+	return n
+}
+
+func sovDenomtrace(x uint64) (n int) {
+	return (math_bits.Len64(x|1) + 6) / 7
+}
+func sozDenomtrace(x uint64) (n int) {
+	return sovDenomtrace(uint64((x << 1) ^ uint64((int64(x) >> 63))))
+}
+func (m *DenomTrace) Unmarshal(dAtA []byte) error {
+	l := len(dAtA)
+	iNdEx := 0
+	for iNdEx < l {
+		preIndex := iNdEx
+		var wire uint64
+		for shift := uint(0); ; shift += 7 {
+			if shift >= 64 {
+				return ErrIntOverflowDenomtrace
+			}
+			if iNdEx >= l {
+				return io.ErrUnexpectedEOF
+			}
+			b := dAtA[iNdEx]
+			iNdEx++
+			wire |= uint64(b&0x7F) << shift
+			if b < 0x80 {
+				break
+			}
+		}
+		fieldNum := int32(wire >> 3)
+		wireType := int(wire & 0x7)
+		if wireType == 4 {
+			return fmt.Errorf("proto: DenomTrace: wiretype end group for non-group")
+		}
+		if fieldNum <= 0 {
+			return fmt.Errorf("proto: DenomTrace: illegal tag %d (wire type %d)", fieldNum, wire)
+		}
+		switch fieldNum {
+		case 1:
+			if wireType != 2 {
+				return fmt.Errorf("proto: wrong wireType = %d for field Path", wireType)
+			}
+			var stringLen uint64
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return ErrIntOverflowDenomtrace
+				}
+				if iNdEx >= l {
+					return io.ErrUnexpectedEOF
+				}
+				b := dAtA[iNdEx]
+				iNdEx++
+				stringLen |= uint64(b&0x7F) << shift
+				if b < 0x80 {
+					break
+				}
+			}
+			intStringLen := int(stringLen)
+			if intStringLen < 0 {
+				return ErrInvalidLengthDenomtrace
+			}
+			postIndex := iNdEx + intStringLen
+			if postIndex < 0 {
+				return ErrInvalidLengthDenomtrace
+			}
+			if postIndex > l {
+				return io.ErrUnexpectedEOF
+			}
+			m.Path = string(dAtA[iNdEx:postIndex])
+			iNdEx = postIndex
+		case 2:
+			if wireType != 2 {
+				return fmt.Errorf("proto: wrong wireType = %d for field BaseDenom", wireType)
+			}
+			var stringLen uint64
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return ErrIntOverflowDenomtrace
+				}
+				if iNdEx >= l {
+					return io.ErrUnexpectedEOF
+				}
+				b := dAtA[iNdEx]
+				iNdEx++
+				stringLen |= uint64(b&0x7F) << shift
+				if b < 0x80 {
+					break
+				}
+			}
+			intStringLen := int(stringLen)
+			if intStringLen < 0 {
+				return ErrInvalidLengthDenomtrace
+			}
+			postIndex := iNdEx + intStringLen
+			if postIndex < 0 {
+				return ErrInvalidLengthDenomtrace
+			}
+			if postIndex > l {
+				return io.ErrUnexpectedEOF
+			}
+			m.BaseDenom = string(dAtA[iNdEx:postIndex])
+			iNdEx = postIndex
+		default:
+			iNdEx = preIndex
+			skippy, err := skipDenomtrace(dAtA[iNdEx:])
+			if err != nil {
+				return err
+			}
+			if (skippy < 0) || (iNdEx+skippy) < 0 {
+				return ErrInvalidLengthDenomtrace
+			}
+			if (iNdEx + skippy) > l {
+				return io.ErrUnexpectedEOF
+			}
+			iNdEx += skippy
+		}
+	}
+
+	if iNdEx > l {
+		return io.ErrUnexpectedEOF
+	}
+	return nil
+}
+func skipDenomtrace(dAtA []byte) (n int, err error) {
+	l := len(dAtA)
+	iNdEx := 0
+	depth := 0
+	for iNdEx < l {
+		var wire uint64
+		for shift := uint(0); ; shift += 7 {
+			if shift >= 64 {
+				return 0, ErrIntOverflowDenomtrace
+			}
+			if iNdEx >= l {
+				return 0, io.ErrUnexpectedEOF
+			}
+			b := dAtA[iNdEx]
+			iNdEx++
+			wire |= (uint64(b) & 0x7F) << shift
+			if b < 0x80 {
+				break
+			}
+		}
+		wireType := int(wire & 0x7)
+		switch wireType {
+		case 0:
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return 0, ErrIntOverflowDenomtrace
+				}
+				if iNdEx >= l {
+					return 0, io.ErrUnexpectedEOF
+				}
+				iNdEx++
+				if dAtA[iNdEx-1] < 0x80 {
+					break
+				}
+			}
+		case 1:
+			iNdEx += 8
+		case 2:
+			var length int
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return 0, ErrIntOverflowDenomtrace
+				}
+				if iNdEx >= l {
+					return 0, io.ErrUnexpectedEOF
+				}
+				b := dAtA[iNdEx]
+				iNdEx++
+				length |= (int(b) & 0x7F) << shift
+				if b < 0x80 {
+					break
+				}
+			}
+			if length < 0 {
+				return 0, ErrInvalidLengthDenomtrace
+			}
+			iNdEx += length
+		case 3:
+			depth++
+		case 4:
+			if depth == 0 {
+				return 0, ErrUnexpectedEndOfGroupDenomtrace
+			}
+			depth--
+		case 5:
+			iNdEx += 4
+		default:
+			return 0, fmt.Errorf("proto: illegal wireType %d", wireType)
+		}
+		if iNdEx < 0 {
+			return 0, ErrInvalidLengthDenomtrace
+		}
+		if depth == 0 {
+			return iNdEx, nil
+		}
+	}
+	return 0, io.ErrUnexpectedEOF
+}
+
+var (
+	ErrInvalidLengthDenomtrace        = fmt.Errorf("proto: negative length found during unmarshaling")
+	ErrIntOverflowDenomtrace          = fmt.Errorf("proto: integer overflow")
+	ErrUnexpectedEndOfGroupDenomtrace = fmt.Errorf("proto: unexpected end of group")
+)
diff --git a/modules/apps/transfer/types/legacy_denomtrace.go b/modules/apps/transfer/internal/types/legacy_denomtrace.go
similarity index 79%
rename from modules/apps/transfer/types/legacy_denomtrace.go
rename to modules/apps/transfer/internal/types/legacy_denomtrace.go
index 3d3adc487ea..ca11d708d74 100644
--- a/modules/apps/transfer/types/legacy_denomtrace.go
+++ b/modules/apps/transfer/internal/types/legacy_denomtrace.go
@@ -5,13 +5,8 @@ import (
 	"fmt"
 
 	cmtbytes "github.com/cometbft/cometbft/libs/bytes"
-)
 
-// TODO: https://github.com/cosmos/ibc-go/issues/6421#issuecomment-2137516426
-// Kept around due to dependency. Empty and useless and ideally dropped before v9.
-type (
-	QueryDenomTracesResponse struct{}
-	QueryDenomTraceResponse  struct{}
+	"github.com/cosmos/ibc-go/v8/modules/apps/transfer/types"
 )
 
 // Hash returns the hex bytes of the SHA256 hash of the DenomTrace fields using the following formula:
@@ -31,7 +26,7 @@ func (dt DenomTrace) GetPrefix() string {
 // 'ibc/{hash(tracePath + baseDenom)}'. If the trace is empty, it will return the base denomination.
 func (dt DenomTrace) IBCDenom() string {
 	if dt.Path != "" {
-		return fmt.Sprintf("%s/%s", DenomPrefix, dt.Hash())
+		return fmt.Sprintf("%s/%s", types.DenomPrefix, dt.Hash())
 	}
 	return dt.BaseDenom
 }
diff --git a/modules/apps/transfer/internal/types/legacy_denomtrace_test.go b/modules/apps/transfer/internal/types/legacy_denomtrace_test.go
new file mode 100644
index 00000000000..9889fa07730
--- /dev/null
+++ b/modules/apps/transfer/internal/types/legacy_denomtrace_test.go
@@ -0,0 +1,27 @@
+package types_test
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+
+	internaltypes "github.com/cosmos/ibc-go/v8/modules/apps/transfer/internal/types"
+)
+
+func TestDenomTrace_IBCDenom(t *testing.T) {
+	testCases := []struct {
+		name     string
+		trace    internaltypes.DenomTrace
+		expDenom string
+	}{
+		{"base denom", internaltypes.DenomTrace{BaseDenom: "uatom"}, "uatom"},
+		{"trace info", internaltypes.DenomTrace{BaseDenom: "uatom", Path: "transfer/channel-1"}, "ibc/C4CFF46FD6DE35CA4CF4CE031E643C8FDC9BA4B99AE598E9B0ED98FE3A2319F9"},
+	}
+
+	for _, tc := range testCases {
+		tc := tc
+
+		denom := tc.trace.IBCDenom()
+		require.Equal(t, tc.expDenom, denom, tc.name)
+	}
+}
diff --git a/modules/apps/transfer/keeper/export_test.go b/modules/apps/transfer/keeper/export_test.go
index 8c6f3961c79..f3f66b3c33e 100644
--- a/modules/apps/transfer/keeper/export_test.go
+++ b/modules/apps/transfer/keeper/export_test.go
@@ -3,23 +3,24 @@ package keeper
 import (
 	sdk "github.com/cosmos/cosmos-sdk/types"
 
+	internaltypes "github.com/cosmos/ibc-go/v8/modules/apps/transfer/internal/types"
 	"github.com/cosmos/ibc-go/v8/modules/apps/transfer/types"
 )
 
 // SetDenomTraces is a wrapper around iterateDenomTraces for testing purposes.
-func (k Keeper) SetDenomTrace(ctx sdk.Context, denomTrace types.DenomTrace) {
+func (k Keeper) SetDenomTrace(ctx sdk.Context, denomTrace internaltypes.DenomTrace) {
 	k.setDenomTrace(ctx, denomTrace)
 }
 
 // IterateDenomTraces is a wrapper around iterateDenomTraces for testing purposes.
-func (k Keeper) IterateDenomTraces(ctx sdk.Context, cb func(denomTrace types.DenomTrace) bool) {
+func (k Keeper) IterateDenomTraces(ctx sdk.Context, cb func(denomTrace internaltypes.DenomTrace) bool) {
 	k.iterateDenomTraces(ctx, cb)
 }
 
 // GetAllDenomTraces returns the trace information for all the denominations.
-func (k Keeper) GetAllDenomTraces(ctx sdk.Context) []types.DenomTrace {
-	var traces []types.DenomTrace
-	k.iterateDenomTraces(ctx, func(denomTrace types.DenomTrace) bool {
+func (k Keeper) GetAllDenomTraces(ctx sdk.Context) []internaltypes.DenomTrace {
+	var traces []internaltypes.DenomTrace
+	k.iterateDenomTraces(ctx, func(denomTrace internaltypes.DenomTrace) bool {
 		traces = append(traces, denomTrace)
 		return false
 	})
diff --git a/modules/apps/transfer/keeper/migrations.go b/modules/apps/transfer/keeper/migrations.go
index 81306a4d986..8376c904644 100644
--- a/modules/apps/transfer/keeper/migrations.go
+++ b/modules/apps/transfer/keeper/migrations.go
@@ -10,6 +10,7 @@ import (
 	sdk "github.com/cosmos/cosmos-sdk/types"
 	banktypes "github.com/cosmos/cosmos-sdk/x/bank/types"
 
+	internaltypes "github.com/cosmos/ibc-go/v8/modules/apps/transfer/internal/types"
 	"github.com/cosmos/ibc-go/v8/modules/apps/transfer/types"
 )
 
@@ -38,7 +39,7 @@ func (m Migrator) MigrateParams(ctx sdk.Context) error {
 // MigrateDenomMetadata sets token metadata for all the IBC denom traces
 func (m Migrator) MigrateDenomMetadata(ctx sdk.Context) error {
 	m.keeper.iterateDenomTraces(ctx,
-		func(dt types.DenomTrace) (stop bool) {
+		func(dt internaltypes.DenomTrace) (stop bool) {
 			// check if the metadata for the given denom trace does not already exist
 			if !m.keeper.bankKeeper.HasDenomMetaData(ctx, dt.IBCDenom()) {
 				m.keeper.setDenomMetadataWithDenomTrace(ctx, dt)
@@ -75,10 +76,10 @@ func (m Migrator) MigrateTotalEscrowForDenom(ctx sdk.Context) error {
 func (m Migrator) MigrateDenomTraceToDenom(ctx sdk.Context) error {
 	var (
 		denoms      []types.Denom
-		denomTraces []types.DenomTrace
+		denomTraces []internaltypes.DenomTrace
 	)
 	m.keeper.iterateDenomTraces(ctx,
-		func(dt types.DenomTrace) (stop bool) {
+		func(dt internaltypes.DenomTrace) (stop bool) {
 			// convert denomTrace to denom
 			denom := types.ExtractDenomFromPath(dt.GetFullDenomPath())
 			err := denom.Validate()
@@ -112,7 +113,7 @@ func (m Migrator) MigrateDenomTraceToDenom(ctx sdk.Context) error {
 }
 
 // setDenomTrace sets a new {trace hash -> denom trace} pair to the store.
-func (k Keeper) setDenomTrace(ctx sdk.Context, denomTrace types.DenomTrace) {
+func (k Keeper) setDenomTrace(ctx sdk.Context, denomTrace internaltypes.DenomTrace) {
 	store := prefix.NewStore(ctx.KVStore(k.storeKey), types.DenomTraceKey)
 	bz := k.cdc.MustMarshal(&denomTrace)
 
@@ -120,20 +121,20 @@ func (k Keeper) setDenomTrace(ctx sdk.Context, denomTrace types.DenomTrace) {
 }
 
 // deleteDenomTrace deletes the denom trace
-func (k Keeper) deleteDenomTrace(ctx sdk.Context, denomTrace types.DenomTrace) {
+func (k Keeper) deleteDenomTrace(ctx sdk.Context, denomTrace internaltypes.DenomTrace) {
 	store := prefix.NewStore(ctx.KVStore(k.storeKey), types.DenomTraceKey)
 	store.Delete(denomTrace.Hash())
 }
 
 // iterateDenomTraces iterates over the denomination traces in the store
 // and performs a callback function.
-func (k Keeper) iterateDenomTraces(ctx sdk.Context, cb func(denomTrace types.DenomTrace) bool) {
+func (k Keeper) iterateDenomTraces(ctx sdk.Context, cb func(denomTrace internaltypes.DenomTrace) bool) {
 	store := ctx.KVStore(k.storeKey)
 	iterator := storetypes.KVStorePrefixIterator(store, types.DenomTraceKey)
 
 	defer sdk.LogDeferred(ctx.Logger(), func() error { return iterator.Close() })
 	for ; iterator.Valid(); iterator.Next() {
-		var denomTrace types.DenomTrace
+		var denomTrace internaltypes.DenomTrace
 		k.cdc.MustUnmarshal(iterator.Value(), &denomTrace)
 
 		if cb(denomTrace) {
@@ -143,7 +144,7 @@ func (k Keeper) iterateDenomTraces(ctx sdk.Context, cb func(denomTrace types.Den
 }
 
 // setDenomMetadataWithDenomTrace sets an IBC token's denomination metadata
-func (k Keeper) setDenomMetadataWithDenomTrace(ctx sdk.Context, denomTrace types.DenomTrace) {
+func (k Keeper) setDenomMetadataWithDenomTrace(ctx sdk.Context, denomTrace internaltypes.DenomTrace) {
 	metadata := banktypes.Metadata{
 		Description: fmt.Sprintf("IBC token from %s", denomTrace.GetFullDenomPath()),
 		DenomUnits: []*banktypes.DenomUnit{
diff --git a/modules/apps/transfer/keeper/migrations_test.go b/modules/apps/transfer/keeper/migrations_test.go
index 3032f6344fe..3e787342f79 100644
--- a/modules/apps/transfer/keeper/migrations_test.go
+++ b/modules/apps/transfer/keeper/migrations_test.go
@@ -9,6 +9,7 @@ import (
 	banktestutil "github.com/cosmos/cosmos-sdk/x/bank/testutil"
 	banktypes "github.com/cosmos/cosmos-sdk/x/bank/types"
 
+	internaltransfertypes "github.com/cosmos/ibc-go/v8/modules/apps/transfer/internal/types"
 	transferkeeper "github.com/cosmos/ibc-go/v8/modules/apps/transfer/keeper"
 	transfertypes "github.com/cosmos/ibc-go/v8/modules/apps/transfer/types"
 	ibctesting "github.com/cosmos/ibc-go/v8/testing"
@@ -59,7 +60,7 @@ func (suite *KeeperTestSuite) TestMigratorMigrateDenomTraceToDenom() {
 			func() {
 				suite.chainA.GetSimApp().TransferKeeper.SetDenomTrace(
 					suite.chainA.GetContext(),
-					transfertypes.DenomTrace{
+					internaltransfertypes.DenomTrace{
 						BaseDenom: "uatom",
 					})
 			},
@@ -72,7 +73,7 @@ func (suite *KeeperTestSuite) TestMigratorMigrateDenomTraceToDenom() {
 			func() {
 				suite.chainA.GetSimApp().TransferKeeper.SetDenomTrace(
 					suite.chainA.GetContext(),
-					transfertypes.DenomTrace{
+					internaltransfertypes.DenomTrace{
 						BaseDenom: "uatom", Path: "transfer/channel-49",
 					})
 			},
@@ -85,7 +86,7 @@ func (suite *KeeperTestSuite) TestMigratorMigrateDenomTraceToDenom() {
 			func() {
 				suite.chainA.GetSimApp().TransferKeeper.SetDenomTrace(
 					suite.chainA.GetContext(),
-					transfertypes.DenomTrace{
+					internaltransfertypes.DenomTrace{
 						BaseDenom: "uatom", Path: "transfer/channel-49/transfer/channel-32/transfer/channel-2",
 					})
 			},
@@ -98,22 +99,22 @@ func (suite *KeeperTestSuite) TestMigratorMigrateDenomTraceToDenom() {
 			func() {
 				suite.chainA.GetSimApp().TransferKeeper.SetDenomTrace(
 					suite.chainA.GetContext(),
-					transfertypes.DenomTrace{
+					internaltransfertypes.DenomTrace{
 						BaseDenom: "uatom", Path: "transfer/channel-49",
 					})
 				suite.chainA.GetSimApp().TransferKeeper.SetDenomTrace(
 					suite.chainA.GetContext(),
-					transfertypes.DenomTrace{
+					internaltransfertypes.DenomTrace{
 						BaseDenom: "pineapple", Path: "transfer/channel-0",
 					})
 				suite.chainA.GetSimApp().TransferKeeper.SetDenomTrace(
 					suite.chainA.GetContext(),
-					transfertypes.DenomTrace{
+					internaltransfertypes.DenomTrace{
 						BaseDenom: "apple", Path: "transfer/channel-0",
 					})
 				suite.chainA.GetSimApp().TransferKeeper.SetDenomTrace(
 					suite.chainA.GetContext(),
-					transfertypes.DenomTrace{
+					internaltransfertypes.DenomTrace{
 						BaseDenom: "cucumber", Path: "transfer/channel-102/transfer/channel-0",
 					})
 			},
@@ -130,7 +131,7 @@ func (suite *KeeperTestSuite) TestMigratorMigrateDenomTraceToDenom() {
 			func() {
 				suite.chainA.GetSimApp().TransferKeeper.SetDenomTrace(
 					suite.chainA.GetContext(),
-					transfertypes.DenomTrace{
+					internaltransfertypes.DenomTrace{
 						BaseDenom: "gamm/pool/1", Path: "transfer/channel-0",
 					})
 			},
@@ -143,7 +144,7 @@ func (suite *KeeperTestSuite) TestMigratorMigrateDenomTraceToDenom() {
 			func() {
 				suite.chainA.GetSimApp().TransferKeeper.SetDenomTrace(
 					suite.chainA.GetContext(),
-					transfertypes.DenomTrace{
+					internaltransfertypes.DenomTrace{
 						BaseDenom: "erc/0x85bcBCd7e79Ec36f4fBBDc54F90C643d921151AA", Path: "transfer/channel-149",
 					})
 			},
@@ -156,7 +157,7 @@ func (suite *KeeperTestSuite) TestMigratorMigrateDenomTraceToDenom() {
 			func() {
 				suite.chainA.GetSimApp().TransferKeeper.SetDenomTrace(
 					suite.chainA.GetContext(),
-					transfertypes.DenomTrace{
+					internaltransfertypes.DenomTrace{
 						BaseDenom: "uatom", Path: "transfer/channel-0/customport/channel-7",
 					})
 			},
@@ -182,7 +183,7 @@ func (suite *KeeperTestSuite) TestMigratorMigrateDenomTraceToDenom() {
 
 			// assert no leftover denom traces
 			suite.chainA.GetSimApp().TransferKeeper.IterateDenomTraces(suite.chainA.GetContext(),
-				func(dt transfertypes.DenomTrace) (stop bool) {
+				func(dt internaltransfertypes.DenomTrace) (stop bool) {
 					suite.FailNow("DenomTrace key still exists", dt)
 					return false
 				},
@@ -194,18 +195,18 @@ func (suite *KeeperTestSuite) TestMigratorMigrateDenomTraceToDenom() {
 func (suite *KeeperTestSuite) TestMigratorMigrateDenomTraceToDenomCorruptionDetection() {
 	testCases := []struct {
 		name       string
-		denomTrace transfertypes.DenomTrace
+		denomTrace internaltransfertypes.DenomTrace
 	}{
 		{
 			"corrupted denom trace, denom.IBCHash() does not match",
-			transfertypes.DenomTrace{
+			internaltransfertypes.DenomTrace{
 				BaseDenom: "customport/channel-0/uatom",
 				Path:      "",
 			},
 		},
 		{
 			"invalid denom trace, base denom is empty",
-			transfertypes.DenomTrace{
+			internaltransfertypes.DenomTrace{
 				BaseDenom: "",
 				Path:      "transfer/channel-0",
 			},
@@ -305,7 +306,7 @@ func (suite *KeeperTestSuite) TestMigrateTotalEscrowForDenom() {
 
 func (suite *KeeperTestSuite) TestMigratorMigrateMetadata() {
 	var (
-		denomTraces      []transfertypes.DenomTrace
+		denomTraces      []internaltransfertypes.DenomTrace
 		expectedMetadata []banktypes.Metadata
 	)
 
@@ -316,7 +317,7 @@ func (suite *KeeperTestSuite) TestMigratorMigrateMetadata() {
 		{
 			"success with one denom trace with one hop",
 			func() {
-				denomTraces = []transfertypes.DenomTrace{
+				denomTraces = []internaltransfertypes.DenomTrace{
 					{
 						BaseDenom: "foo",
 						Path:      "transfer/channel-0",
@@ -343,7 +344,7 @@ func (suite *KeeperTestSuite) TestMigratorMigrateMetadata() {
 		{
 			"success with one denom trace with two hops",
 			func() {
-				denomTraces = []transfertypes.DenomTrace{
+				denomTraces = []internaltransfertypes.DenomTrace{
 					{
 						BaseDenom: "ubar",
 						Path:      "transfer/channel-1/transfer/channel-2",
@@ -370,7 +371,7 @@ func (suite *KeeperTestSuite) TestMigratorMigrateMetadata() {
 		{
 			"success with two denom traces with one hop",
 			func() {
-				denomTraces = []transfertypes.DenomTrace{
+				denomTraces = []internaltransfertypes.DenomTrace{
 					{
 						BaseDenom: "foo",
 						Path:      "transfer/channel-0",
@@ -414,7 +415,7 @@ func (suite *KeeperTestSuite) TestMigratorMigrateMetadata() {
 		{
 			"success with two denom traces, metadata for one of them already exists",
 			func() {
-				denomTraces = []transfertypes.DenomTrace{
+				denomTraces = []internaltransfertypes.DenomTrace{
 					{
 						BaseDenom: "foo",
 						Path:      "transfer/channel-0",
diff --git a/modules/apps/transfer/keeper/relay_test.go b/modules/apps/transfer/keeper/relay_test.go
index 630bfac7a24..8ae020b192b 100644
--- a/modules/apps/transfer/keeper/relay_test.go
+++ b/modules/apps/transfer/keeper/relay_test.go
@@ -12,6 +12,7 @@ import (
 	banktestutil "github.com/cosmos/cosmos-sdk/x/bank/testutil"
 	banktypes "github.com/cosmos/cosmos-sdk/x/bank/types"
 
+	internaltypes "github.com/cosmos/ibc-go/v8/modules/apps/transfer/internal/types"
 	transferkeeper "github.com/cosmos/ibc-go/v8/modules/apps/transfer/keeper"
 	"github.com/cosmos/ibc-go/v8/modules/apps/transfer/types"
 	clienttypes "github.com/cosmos/ibc-go/v8/modules/core/02-client/types"
@@ -617,7 +618,7 @@ func (suite *KeeperTestSuite) TestOnRecvPacketSetsTotalEscrowAmountForSourceIBCT
 	path2.Setup()
 
 	// denomTrace path: {transfer/channel-1/transfer/channel-0}
-	denomTrace := types.DenomTrace{
+	denomTrace := internaltypes.DenomTrace{
 		BaseDenom: sdk.DefaultBondDenom,
 		Path:      fmt.Sprintf("%s/%s/%s/%s", path2.EndpointA.ChannelConfig.PortID, path2.EndpointA.ChannelID, path1.EndpointB.ChannelConfig.PortID, path1.EndpointB.ChannelID),
 	}
@@ -642,7 +643,7 @@ func (suite *KeeperTestSuite) TestOnRecvPacketSetsTotalEscrowAmountForSourceIBCT
 
 	// fund escrow account for transfer and channel-1 on chain B
 	// denomTrace path: transfer/channel-0
-	denomTrace = types.DenomTrace{
+	denomTrace = internaltypes.DenomTrace{
 		BaseDenom: sdk.DefaultBondDenom,
 		Path:      fmt.Sprintf("%s/%s", path1.EndpointB.ChannelConfig.PortID, path1.EndpointB.ChannelID),
 	}
@@ -831,7 +832,7 @@ func (suite *KeeperTestSuite) TestOnAcknowledgementPacketSetsTotalEscrowAmountFo
 
 	// fund escrow account for transfer and channel-1 on chain B
 	// denomTrace path = transfer/channel-0
-	denomTrace := types.DenomTrace{
+	denomTrace := internaltypes.DenomTrace{
 		BaseDenom: sdk.DefaultBondDenom,
 		Path:      fmt.Sprintf("%s/%s", path1.EndpointB.ChannelConfig.PortID, path1.EndpointB.ChannelID),
 	}
@@ -1045,7 +1046,7 @@ func (suite *KeeperTestSuite) TestOnTimeoutPacketSetsTotalEscrowAmountForSourceI
 	path2.Setup()
 
 	// fund escrow account for transfer and channel-1 on chain B
-	denomTrace := types.DenomTrace{
+	denomTrace := internaltypes.DenomTrace{
 		BaseDenom: sdk.DefaultBondDenom,
 		Path:      fmt.Sprintf("%s/%s", path1.EndpointB.ChannelConfig.PortID, path1.EndpointB.ChannelID),
 	}
diff --git a/modules/apps/transfer/simulation/decoder.go b/modules/apps/transfer/simulation/decoder.go
index c224b76cfd4..a8a9ea7f7ed 100644
--- a/modules/apps/transfer/simulation/decoder.go
+++ b/modules/apps/transfer/simulation/decoder.go
@@ -6,6 +6,7 @@ import (
 
 	"github.com/cosmos/cosmos-sdk/types/kv"
 
+	internaltypes "github.com/cosmos/ibc-go/v8/modules/apps/transfer/internal/types"
 	"github.com/cosmos/ibc-go/v8/modules/apps/transfer/types"
 )
 
@@ -18,7 +19,7 @@ func NewDecodeStore() func(kvA, kvB kv.Pair) string {
 			return fmt.Sprintf("Port A: %s\nPort B: %s", string(kvA.Value), string(kvB.Value))
 
 		case bytes.Equal(kvA.Key[:1], types.DenomTraceKey):
-			var denomTraceA, denomTraceB types.DenomTrace
+			var denomTraceA, denomTraceB internaltypes.DenomTrace
 			types.ModuleCdc.MustUnmarshal(kvA.Value, &denomTraceA)
 			types.ModuleCdc.MustUnmarshal(kvB.Value, &denomTraceB)
 			return fmt.Sprintf("DenomTrace A: %s\nDenomTrace B: %s", denomTraceA.IBCDenom(), denomTraceB.IBCDenom())
diff --git a/modules/apps/transfer/simulation/decoder_test.go b/modules/apps/transfer/simulation/decoder_test.go
index 29a77ced412..95603c67dbd 100644
--- a/modules/apps/transfer/simulation/decoder_test.go
+++ b/modules/apps/transfer/simulation/decoder_test.go
@@ -8,6 +8,7 @@ import (
 
 	"github.com/cosmos/cosmos-sdk/types/kv"
 
+	internaltypes "github.com/cosmos/ibc-go/v8/modules/apps/transfer/internal/types"
 	"github.com/cosmos/ibc-go/v8/modules/apps/transfer/simulation"
 	"github.com/cosmos/ibc-go/v8/modules/apps/transfer/types"
 )
@@ -15,7 +16,7 @@ import (
 func TestDecodeStore(t *testing.T) {
 	dec := simulation.NewDecodeStore()
 
-	trace := types.DenomTrace{
+	trace := internaltypes.DenomTrace{
 		BaseDenom: "uatom",
 		Path:      "transfer/channelToA",
 	}
diff --git a/modules/apps/transfer/types/legacy_denomtrace_responses.go b/modules/apps/transfer/types/legacy_denomtrace_responses.go
new file mode 100644
index 00000000000..b1ca1bf2093
--- /dev/null
+++ b/modules/apps/transfer/types/legacy_denomtrace_responses.go
@@ -0,0 +1,8 @@
+package types
+
+// TODO: https://github.com/cosmos/ibc-go/issues/6421#issuecomment-2137516426
+// Kept around due to dependency. Empty and useless and ideally dropped before v9.
+type (
+	QueryDenomTracesResponse struct{}
+	QueryDenomTraceResponse  struct{}
+)
diff --git a/modules/apps/transfer/types/legacy_denomtrace_test.go b/modules/apps/transfer/types/legacy_denomtrace_test.go
deleted file mode 100644
index 7339120cab6..00000000000
--- a/modules/apps/transfer/types/legacy_denomtrace_test.go
+++ /dev/null
@@ -1,27 +0,0 @@
-package types_test
-
-import (
-	"testing"
-
-	"github.com/stretchr/testify/require"
-
-	"github.com/cosmos/ibc-go/v8/modules/apps/transfer/types"
-)
-
-func TestDenomTrace_IBCDenom(t *testing.T) {
-	testCases := []struct {
-		name     string
-		trace    types.DenomTrace
-		expDenom string
-	}{
-		{"base denom", types.DenomTrace{BaseDenom: "uatom"}, "uatom"},
-		{"trace info", types.DenomTrace{BaseDenom: "uatom", Path: "transfer/channel-1"}, "ibc/C4CFF46FD6DE35CA4CF4CE031E643C8FDC9BA4B99AE598E9B0ED98FE3A2319F9"},
-	}
-
-	for _, tc := range testCases {
-		tc := tc
-
-		denom := tc.trace.IBCDenom()
-		require.Equal(t, tc.expDenom, denom, tc.name)
-	}
-}
diff --git a/modules/apps/transfer/types/transfer.pb.go b/modules/apps/transfer/types/transfer.pb.go
index 99bfa07a587..18086ea38a4 100644
--- a/modules/apps/transfer/types/transfer.pb.go
+++ b/modules/apps/transfer/types/transfer.pb.go
@@ -22,63 +22,6 @@ var _ = math.Inf
 // proto package needs to be updated.
 const _ = proto.GoGoProtoPackageIsVersion3 // please upgrade the proto package
 
-// DenomTrace contains the base denomination for ICS20 fungible tokens and the
-// source tracing information path.
-type DenomTrace struct {
-	// path defines the chain of port/channel identifiers used for tracing the
-	// source of the fungible token.
-	Path string `protobuf:"bytes,1,opt,name=path,proto3" json:"path,omitempty"`
-	// base denomination of the relayed fungible token.
-	BaseDenom string `protobuf:"bytes,2,opt,name=base_denom,json=baseDenom,proto3" json:"base_denom,omitempty"`
-}
-
-func (m *DenomTrace) Reset()         { *m = DenomTrace{} }
-func (m *DenomTrace) String() string { return proto.CompactTextString(m) }
-func (*DenomTrace) ProtoMessage()    {}
-func (*DenomTrace) Descriptor() ([]byte, []int) {
-	return fileDescriptor_5041673e96e97901, []int{0}
-}
-func (m *DenomTrace) XXX_Unmarshal(b []byte) error {
-	return m.Unmarshal(b)
-}
-func (m *DenomTrace) XXX_Marshal(b []byte, deterministic bool) ([]byte, error) {
-	if deterministic {
-		return xxx_messageInfo_DenomTrace.Marshal(b, m, deterministic)
-	} else {
-		b = b[:cap(b)]
-		n, err := m.MarshalToSizedBuffer(b)
-		if err != nil {
-			return nil, err
-		}
-		return b[:n], nil
-	}
-}
-func (m *DenomTrace) XXX_Merge(src proto.Message) {
-	xxx_messageInfo_DenomTrace.Merge(m, src)
-}
-func (m *DenomTrace) XXX_Size() int {
-	return m.Size()
-}
-func (m *DenomTrace) XXX_DiscardUnknown() {
-	xxx_messageInfo_DenomTrace.DiscardUnknown(m)
-}
-
-var xxx_messageInfo_DenomTrace proto.InternalMessageInfo
-
-func (m *DenomTrace) GetPath() string {
-	if m != nil {
-		return m.Path
-	}
-	return ""
-}
-
-func (m *DenomTrace) GetBaseDenom() string {
-	if m != nil {
-		return m.BaseDenom
-	}
-	return ""
-}
-
 // Params defines the set of IBC transfer parameters.
 // NOTE: To prevent a single token from being transferred, set the
 // TransfersEnabled parameter to true and then set the bank module's SendEnabled
@@ -96,7 +39,7 @@ func (m *Params) Reset()         { *m = Params{} }
 func (m *Params) String() string { return proto.CompactTextString(m) }
 func (*Params) ProtoMessage()    {}
 func (*Params) Descriptor() ([]byte, []int) {
-	return fileDescriptor_5041673e96e97901, []int{1}
+	return fileDescriptor_5041673e96e97901, []int{0}
 }
 func (m *Params) XXX_Unmarshal(b []byte) error {
 	return m.Unmarshal(b)
@@ -140,7 +83,6 @@ func (m *Params) GetReceiveEnabled() bool {
 }
 
 func init() {
-	proto.RegisterType((*DenomTrace)(nil), "ibc.applications.transfer.v1.DenomTrace")
 	proto.RegisterType((*Params)(nil), "ibc.applications.transfer.v1.Params")
 }
 
@@ -149,60 +91,21 @@ func init() {
 }
 
 var fileDescriptor_5041673e96e97901 = []byte{
-	// 256 bytes of a gzipped FileDescriptorProto
-	0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0xff, 0x4c, 0x90, 0x3f, 0x4b, 0x03, 0x31,
-	0x18, 0x87, 0x9b, 0x22, 0xc5, 0x46, 0x51, 0xc8, 0xd4, 0x41, 0x83, 0x76, 0x51, 0x10, 0x2f, 0x14,
-	0x07, 0xdd, 0x04, 0xd1, 0x5d, 0x4b, 0x27, 0x97, 0x92, 0xe4, 0x5e, 0xdb, 0xc0, 0xe5, 0x0f, 0x79,
-	0xd3, 0x03, 0xbf, 0x85, 0x1f, 0xcb, 0xb1, 0xa3, 0xa3, 0xdc, 0x7d, 0x11, 0xb9, 0x58, 0x8e, 0x6e,
-	0x3f, 0x9e, 0x3c, 0x79, 0x87, 0x87, 0xde, 0x18, 0xa5, 0x85, 0x0c, 0xa1, 0x32, 0x5a, 0x26, 0xe3,
-	0x1d, 0x8a, 0x14, 0xa5, 0xc3, 0x0f, 0x88, 0xa2, 0x9e, 0xf5, 0xbb, 0x08, 0xd1, 0x27, 0xcf, 0xce,
-	0x8c, 0xd2, 0xc5, 0xbe, 0x5c, 0xf4, 0x42, 0x3d, 0x9b, 0x3e, 0x52, 0xfa, 0x0c, 0xce, 0xdb, 0x45,
-	0x94, 0x1a, 0x18, 0xa3, 0x07, 0x41, 0xa6, 0xf5, 0x84, 0x5c, 0x90, 0xeb, 0xf1, 0x3c, 0x6f, 0x76,
-	0x4e, 0xa9, 0x92, 0x08, 0xcb, 0xb2, 0xd3, 0x26, 0xc3, 0xfc, 0x32, 0xee, 0x48, 0xfe, 0x37, 0x5d,
-	0xd0, 0xd1, 0xab, 0x8c, 0xd2, 0x22, 0xbb, 0xa4, 0xc7, 0x08, 0xae, 0x5c, 0x82, 0x93, 0xaa, 0x82,
-	0x32, 0x1f, 0x39, 0x9c, 0x1f, 0x75, 0xec, 0xe5, 0x1f, 0xb1, 0x2b, 0x7a, 0x1a, 0x41, 0x83, 0xa9,
-	0xa1, 0xb7, 0x86, 0xd9, 0x3a, 0xd9, 0xe1, 0x9d, 0xf8, 0xf4, 0xf6, 0xdd, 0x70, 0xb2, 0x6d, 0x38,
-	0xf9, 0x6d, 0x38, 0xf9, 0x6a, 0xf9, 0x60, 0xdb, 0xf2, 0xc1, 0x4f, 0xcb, 0x07, 0xef, 0xf7, 0x2b,
-	0x93, 0xd6, 0x1b, 0x55, 0x68, 0x6f, 0x85, 0xf6, 0x68, 0x3d, 0x0a, 0xa3, 0xf4, 0xed, 0xca, 0x8b,
-	0xfa, 0x41, 0x58, 0x5f, 0x6e, 0x2a, 0xc0, 0xae, 0xcd, 0x5e, 0x93, 0xf4, 0x19, 0x00, 0xd5, 0x28,
-	0xe7, 0xb8, 0xfb, 0x0b, 0x00, 0x00, 0xff, 0xff, 0x24, 0x39, 0xe1, 0x5f, 0x3d, 0x01, 0x00, 0x00,
-}
-
-func (m *DenomTrace) Marshal() (dAtA []byte, err error) {
-	size := m.Size()
-	dAtA = make([]byte, size)
-	n, err := m.MarshalToSizedBuffer(dAtA[:size])
-	if err != nil {
-		return nil, err
-	}
-	return dAtA[:n], nil
-}
-
-func (m *DenomTrace) MarshalTo(dAtA []byte) (int, error) {
-	size := m.Size()
-	return m.MarshalToSizedBuffer(dAtA[:size])
-}
-
-func (m *DenomTrace) MarshalToSizedBuffer(dAtA []byte) (int, error) {
-	i := len(dAtA)
-	_ = i
-	var l int
-	_ = l
-	if len(m.BaseDenom) > 0 {
-		i -= len(m.BaseDenom)
-		copy(dAtA[i:], m.BaseDenom)
-		i = encodeVarintTransfer(dAtA, i, uint64(len(m.BaseDenom)))
-		i--
-		dAtA[i] = 0x12
-	}
-	if len(m.Path) > 0 {
-		i -= len(m.Path)
-		copy(dAtA[i:], m.Path)
-		i = encodeVarintTransfer(dAtA, i, uint64(len(m.Path)))
-		i--
-		dAtA[i] = 0xa
-	}
-	return len(dAtA) - i, nil
+	// 214 bytes of a gzipped FileDescriptorProto
+	0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0xff, 0xe2, 0xd2, 0xce, 0x4c, 0x4a, 0xd6,
+	0x4f, 0x2c, 0x28, 0xc8, 0xc9, 0x4c, 0x4e, 0x2c, 0xc9, 0xcc, 0xcf, 0x2b, 0xd6, 0x2f, 0x29, 0x4a,
+	0xcc, 0x2b, 0x4e, 0x4b, 0x2d, 0xd2, 0x2f, 0x33, 0x84, 0xb3, 0xf5, 0x0a, 0x8a, 0xf2, 0x4b, 0xf2,
+	0x85, 0x64, 0x32, 0x93, 0x92, 0xf5, 0x90, 0x15, 0xeb, 0xc1, 0x15, 0x94, 0x19, 0x2a, 0x85, 0x70,
+	0xb1, 0x05, 0x24, 0x16, 0x25, 0xe6, 0x16, 0x0b, 0x29, 0x72, 0xf1, 0x14, 0xa7, 0xe6, 0xa5, 0xc4,
+	0xa7, 0xe6, 0x25, 0x26, 0xe5, 0xa4, 0xa6, 0x48, 0x30, 0x2a, 0x30, 0x6a, 0x70, 0x04, 0x71, 0x83,
+	0xc4, 0x5c, 0x21, 0x42, 0x42, 0xea, 0x5c, 0xfc, 0x45, 0xa9, 0xc9, 0xa9, 0x99, 0x65, 0xa9, 0x70,
+	0x55, 0x4c, 0x60, 0x55, 0x7c, 0x50, 0x61, 0xa8, 0x42, 0xa7, 0xc0, 0x13, 0x8f, 0xe4, 0x18, 0x2f,
+	0x3c, 0x92, 0x63, 0x7c, 0xf0, 0x48, 0x8e, 0x71, 0xc2, 0x63, 0x39, 0x86, 0x0b, 0x8f, 0xe5, 0x18,
+	0x6e, 0x3c, 0x96, 0x63, 0x88, 0x32, 0x4f, 0xcf, 0x2c, 0xc9, 0x28, 0x4d, 0xd2, 0x4b, 0xce, 0xcf,
+	0xd5, 0x4f, 0xce, 0x2f, 0xce, 0xcd, 0x2f, 0xd6, 0xcf, 0x4c, 0x4a, 0xd6, 0x4d, 0xcf, 0xd7, 0x2f,
+	0xb3, 0xd0, 0xcf, 0xcd, 0x4f, 0x29, 0xcd, 0x49, 0x2d, 0x06, 0x79, 0x0d, 0xc9, 0x4b, 0x25, 0x95,
+	0x05, 0xa9, 0xc5, 0x49, 0x6c, 0x60, 0xdf, 0x18, 0x03, 0x02, 0x00, 0x00, 0xff, 0xff, 0xc7, 0x93,
+	0x43, 0xf8, 0xfc, 0x00, 0x00, 0x00,
 }
 
 func (m *Params) Marshal() (dAtA []byte, err error) {
@@ -259,23 +162,6 @@ func encodeVarintTransfer(dAtA []byte, offset int, v uint64) int {
 	dAtA[offset] = uint8(v)
 	return base
 }
-func (m *DenomTrace) Size() (n int) {
-	if m == nil {
-		return 0
-	}
-	var l int
-	_ = l
-	l = len(m.Path)
-	if l > 0 {
-		n += 1 + l + sovTransfer(uint64(l))
-	}
-	l = len(m.BaseDenom)
-	if l > 0 {
-		n += 1 + l + sovTransfer(uint64(l))
-	}
-	return n
-}
-
 func (m *Params) Size() (n int) {
 	if m == nil {
 		return 0
@@ -297,120 +183,6 @@ func sovTransfer(x uint64) (n int) {
 func sozTransfer(x uint64) (n int) {
 	return sovTransfer(uint64((x << 1) ^ uint64((int64(x) >> 63))))
 }
-func (m *DenomTrace) Unmarshal(dAtA []byte) error {
-	l := len(dAtA)
-	iNdEx := 0
-	for iNdEx < l {
-		preIndex := iNdEx
-		var wire uint64
-		for shift := uint(0); ; shift += 7 {
-			if shift >= 64 {
-				return ErrIntOverflowTransfer
-			}
-			if iNdEx >= l {
-				return io.ErrUnexpectedEOF
-			}
-			b := dAtA[iNdEx]
-			iNdEx++
-			wire |= uint64(b&0x7F) << shift
-			if b < 0x80 {
-				break
-			}
-		}
-		fieldNum := int32(wire >> 3)
-		wireType := int(wire & 0x7)
-		if wireType == 4 {
-			return fmt.Errorf("proto: DenomTrace: wiretype end group for non-group")
-		}
-		if fieldNum <= 0 {
-			return fmt.Errorf("proto: DenomTrace: illegal tag %d (wire type %d)", fieldNum, wire)
-		}
-		switch fieldNum {
-		case 1:
-			if wireType != 2 {
-				return fmt.Errorf("proto: wrong wireType = %d for field Path", wireType)
-			}
-			var stringLen uint64
-			for shift := uint(0); ; shift += 7 {
-				if shift >= 64 {
-					return ErrIntOverflowTransfer
-				}
-				if iNdEx >= l {
-					return io.ErrUnexpectedEOF
-				}
-				b := dAtA[iNdEx]
-				iNdEx++
-				stringLen |= uint64(b&0x7F) << shift
-				if b < 0x80 {
-					break
-				}
-			}
-			intStringLen := int(stringLen)
-			if intStringLen < 0 {
-				return ErrInvalidLengthTransfer
-			}
-			postIndex := iNdEx + intStringLen
-			if postIndex < 0 {
-				return ErrInvalidLengthTransfer
-			}
-			if postIndex > l {
-				return io.ErrUnexpectedEOF
-			}
-			m.Path = string(dAtA[iNdEx:postIndex])
-			iNdEx = postIndex
-		case 2:
-			if wireType != 2 {
-				return fmt.Errorf("proto: wrong wireType = %d for field BaseDenom", wireType)
-			}
-			var stringLen uint64
-			for shift := uint(0); ; shift += 7 {
-				if shift >= 64 {
-					return ErrIntOverflowTransfer
-				}
-				if iNdEx >= l {
-					return io.ErrUnexpectedEOF
-				}
-				b := dAtA[iNdEx]
-				iNdEx++
-				stringLen |= uint64(b&0x7F) << shift
-				if b < 0x80 {
-					break
-				}
-			}
-			intStringLen := int(stringLen)
-			if intStringLen < 0 {
-				return ErrInvalidLengthTransfer
-			}
-			postIndex := iNdEx + intStringLen
-			if postIndex < 0 {
-				return ErrInvalidLengthTransfer
-			}
-			if postIndex > l {
-				return io.ErrUnexpectedEOF
-			}
-			m.BaseDenom = string(dAtA[iNdEx:postIndex])
-			iNdEx = postIndex
-		default:
-			iNdEx = preIndex
-			skippy, err := skipTransfer(dAtA[iNdEx:])
-			if err != nil {
-				return err
-			}
-			if (skippy < 0) || (iNdEx+skippy) < 0 {
-				return ErrInvalidLengthTransfer
-			}
-			if (iNdEx + skippy) > l {
-				return io.ErrUnexpectedEOF
-			}
-			iNdEx += skippy
-		}
-	}
-
-	if iNdEx > l {
-		return io.ErrUnexpectedEOF
-	}
-	return nil
-}
 func (m *Params) Unmarshal(dAtA []byte) error {
 	l := len(dAtA)
 	iNdEx := 0
diff --git a/proto/ibc/applications/transfer/v1/denomtrace.proto b/proto/ibc/applications/transfer/v1/denomtrace.proto
new file mode 100644
index 00000000000..bd301add8b0
--- /dev/null
+++ b/proto/ibc/applications/transfer/v1/denomtrace.proto
@@ -0,0 +1,15 @@
+syntax = "proto3";
+
+package ibc.applications.transfer.v1;
+
+option go_package = "github.com/cosmos/ibc-go/v8/modules/apps/transfer/types";
+
+// DenomTrace contains the base denomination for ICS20 fungible tokens and the
+// source tracing information path.
+message DenomTrace {
+  // path defines the chain of port/channel identifiers used for tracing the
+  // source of the fungible token.
+  string path = 1;
+  // base denomination of the relayed fungible token.
+  string base_denom = 2;
+}
diff --git a/proto/ibc/applications/transfer/v1/transfer.proto b/proto/ibc/applications/transfer/v1/transfer.proto
index 7f77237621f..15ce7a40e59 100644
--- a/proto/ibc/applications/transfer/v1/transfer.proto
+++ b/proto/ibc/applications/transfer/v1/transfer.proto
@@ -4,16 +4,6 @@ package ibc.applications.transfer.v1;
 
 option go_package = "github.com/cosmos/ibc-go/v8/modules/apps/transfer/types";
 
-// DenomTrace contains the base denomination for ICS20 fungible tokens and the
-// source tracing information path.
-message DenomTrace {
-  // path defines the chain of port/channel identifiers used for tracing the
-  // source of the fungible token.
-  string path = 1;
-  // base denomination of the relayed fungible token.
-  string base_denom = 2;
-}
-
 // Params defines the set of IBC transfer parameters.
 // NOTE: To prevent a single token from being transferred, set the
 // TransfersEnabled parameter to true and then set the bank module's SendEnabled
diff --git a/scripts/protocgen.sh b/scripts/protocgen.sh
index 92fcc89a936..e25c443039f 100755
--- a/scripts/protocgen.sh
+++ b/scripts/protocgen.sh
@@ -14,4 +14,7 @@ cp -r github.com/cosmos/ibc-go/v*/modules/* modules/
 cp -r github.com/cosmos/ibc-go/modules/* modules/
 rm -rf github.com
 
+# copy legacy denom trace to internal/types
+mv modules/apps/transfer/types/denomtrace.pb.go modules/apps/transfer/internal/types/
+
 go mod tidy

From 4b7ca0e8fc0ba5eba05b35c65110065716b64c41 Mon Sep 17 00:00:00 2001
From: DimitrisJim <d.f.hilliard@gmail.com>
Date: Wed, 5 Jun 2024 17:54:46 +0300
Subject: [PATCH 2/4] post merge minor fixes

---
 modules/apps/transfer/keeper/relay_test.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/modules/apps/transfer/keeper/relay_test.go b/modules/apps/transfer/keeper/relay_test.go
index 63c728e2a25..bb3b2094852 100644
--- a/modules/apps/transfer/keeper/relay_test.go
+++ b/modules/apps/transfer/keeper/relay_test.go
@@ -12,7 +12,6 @@ import (
 	banktestutil "github.com/cosmos/cosmos-sdk/x/bank/testutil"
 	banktypes "github.com/cosmos/cosmos-sdk/x/bank/types"
 
-	internaltypes "github.com/cosmos/ibc-go/v8/modules/apps/transfer/internal/types"
 	transferkeeper "github.com/cosmos/ibc-go/v8/modules/apps/transfer/keeper"
 	"github.com/cosmos/ibc-go/v8/modules/apps/transfer/types"
 	clienttypes "github.com/cosmos/ibc-go/v8/modules/core/02-client/types"
@@ -642,6 +641,7 @@ func (suite *KeeperTestSuite) TestOnRecvPacketSetsTotalEscrowAmountForSourceIBCT
 		timeout, 0,
 	)
 
+	// fund escrow account for transfer and channel-1 on chain B
 	// denom path: transfer/channel-0
 	denom = types.NewDenom(
 		sdk.DefaultBondDenom,

From a516e3608e8446495354c15fa1aaf3935b489163 Mon Sep 17 00:00:00 2001
From: DimitrisJim <d.f.hilliard@gmail.com>
Date: Wed, 5 Jun 2024 18:33:20 +0300
Subject: [PATCH 3/4] mark message as deprecated, add changelog.

---
 CHANGELOG.md                                  |  1 +
 .../transfer/internal/types/denomtrace.pb.go  | 20 ++++++++++---------
 .../applications/transfer/v1/denomtrace.proto |  1 +
 3 files changed, 13 insertions(+), 9 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 94cb06fc17d..6cc509876bf 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -57,6 +57,7 @@ Ref: https://keepachangelog.com/en/1.0.0/
 * (core/05-port) [\#6341](https://github.com/cosmos/ibc-go/pull/6341) Modify `UnmarshalPacketData` interface to take in the context, portID, and channelID. This allows for packet data's to be unmarshaled based on the channel version.
 * (apps/27-interchain-accounts) [\#6433](https://github.com/cosmos/ibc-go/pull/6433) Use UNORDERED as the default ordering for new ICA channels.
 * (apps/transfer) [\#6440](https://github.com/cosmos/ibc-go/pull/6440) Remove `GetPrefixedDenom`.
+* (apps/transfer) [\#6508](https://github.com/cosmos/ibc-go/pull/6508) Remove the DenomTrace type.
 
 ### State Machine Breaking
 
diff --git a/modules/apps/transfer/internal/types/denomtrace.pb.go b/modules/apps/transfer/internal/types/denomtrace.pb.go
index 4aed671f205..6d7ee29ad75 100644
--- a/modules/apps/transfer/internal/types/denomtrace.pb.go
+++ b/modules/apps/transfer/internal/types/denomtrace.pb.go
@@ -24,6 +24,8 @@ const _ = proto.GoGoProtoPackageIsVersion3 // please upgrade the proto package
 
 // DenomTrace contains the base denomination for ICS20 fungible tokens and the
 // source tracing information path.
+//
+// Deprecated: Do not use.
 type DenomTrace struct {
 	// path defines the chain of port/channel identifiers used for tracing the
 	// source of the fungible token.
@@ -88,21 +90,21 @@ func init() {
 }
 
 var fileDescriptor_c400148599bf8bc8 = []byte{
-	// 211 bytes of a gzipped FileDescriptorProto
+	// 215 bytes of a gzipped FileDescriptorProto
 	0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0xff, 0xe2, 0xd2, 0xcd, 0x4c, 0x4a, 0xd6,
 	0x4f, 0x2c, 0x28, 0xc8, 0xc9, 0x4c, 0x4e, 0x2c, 0xc9, 0xcc, 0xcf, 0x2b, 0xd6, 0x2f, 0x29, 0x4a,
 	0xcc, 0x2b, 0x4e, 0x4b, 0x2d, 0xd2, 0x2f, 0x33, 0xd4, 0x4f, 0x49, 0xcd, 0xcb, 0xcf, 0x2d, 0x29,
 	0x4a, 0x4c, 0x4e, 0xd5, 0x2b, 0x28, 0xca, 0x2f, 0xc9, 0x17, 0x92, 0xc9, 0x4c, 0x4a, 0xd6, 0x43,
-	0x56, 0xae, 0x07, 0x53, 0xae, 0x57, 0x66, 0xa8, 0x64, 0xcf, 0xc5, 0xe5, 0x02, 0xd2, 0x11, 0x02,
+	0x56, 0xae, 0x07, 0x53, 0xae, 0x57, 0x66, 0xa8, 0xe4, 0xcc, 0xc5, 0xe5, 0x02, 0xd2, 0x11, 0x02,
 	0xd2, 0x21, 0x24, 0xc4, 0xc5, 0x52, 0x90, 0x58, 0x92, 0x21, 0xc1, 0xa8, 0xc0, 0xa8, 0xc1, 0x19,
 	0x04, 0x66, 0x0b, 0xc9, 0x72, 0x71, 0x25, 0x25, 0x16, 0xa7, 0xc6, 0x83, 0x0d, 0x96, 0x60, 0x02,
-	0xcb, 0x70, 0x82, 0x44, 0xc0, 0xfa, 0x9c, 0x02, 0x4f, 0x3c, 0x92, 0x63, 0xbc, 0xf0, 0x48, 0x8e,
-	0xf1, 0xc1, 0x23, 0x39, 0xc6, 0x09, 0x8f, 0xe5, 0x18, 0x2e, 0x3c, 0x96, 0x63, 0xb8, 0xf1, 0x58,
-	0x8e, 0x21, 0xca, 0x3c, 0x3d, 0xb3, 0x24, 0xa3, 0x34, 0x49, 0x2f, 0x39, 0x3f, 0x57, 0x3f, 0x39,
-	0xbf, 0x38, 0x37, 0xbf, 0x58, 0x3f, 0x33, 0x29, 0x59, 0x37, 0x3d, 0x5f, 0xbf, 0xcc, 0x42, 0x3f,
-	0x37, 0x3f, 0xa5, 0x34, 0x27, 0xb5, 0x18, 0xe4, 0x0f, 0x24, 0xf7, 0x97, 0x54, 0x16, 0xa4, 0x16,
-	0x27, 0xb1, 0x81, 0x1d, 0x6e, 0x0c, 0x08, 0x00, 0x00, 0xff, 0xff, 0xa6, 0xd5, 0xd9, 0xdc, 0xe9,
-	0x00, 0x00, 0x00,
+	0xcb, 0x70, 0x82, 0x44, 0xc0, 0xfa, 0xac, 0x98, 0x24, 0x18, 0x9d, 0x02, 0x4f, 0x3c, 0x92, 0x63,
+	0xbc, 0xf0, 0x48, 0x8e, 0xf1, 0xc1, 0x23, 0x39, 0xc6, 0x09, 0x8f, 0xe5, 0x18, 0x2e, 0x3c, 0x96,
+	0x63, 0xb8, 0xf1, 0x58, 0x8e, 0x21, 0xca, 0x3c, 0x3d, 0xb3, 0x24, 0xa3, 0x34, 0x49, 0x2f, 0x39,
+	0x3f, 0x57, 0x3f, 0x39, 0xbf, 0x38, 0x37, 0xbf, 0x58, 0x3f, 0x33, 0x29, 0x59, 0x37, 0x3d, 0x5f,
+	0xbf, 0xcc, 0x42, 0x3f, 0x37, 0x3f, 0xa5, 0x34, 0x27, 0xb5, 0x18, 0xe4, 0x17, 0x24, 0x3f, 0x94,
+	0x54, 0x16, 0xa4, 0x16, 0x27, 0xb1, 0x81, 0x1d, 0x6f, 0x0c, 0x08, 0x00, 0x00, 0xff, 0xff, 0x40,
+	0x87, 0xd3, 0x61, 0xed, 0x00, 0x00, 0x00,
 }
 
 func (m *DenomTrace) Marshal() (dAtA []byte, err error) {
diff --git a/proto/ibc/applications/transfer/v1/denomtrace.proto b/proto/ibc/applications/transfer/v1/denomtrace.proto
index bd301add8b0..9ac7e093573 100644
--- a/proto/ibc/applications/transfer/v1/denomtrace.proto
+++ b/proto/ibc/applications/transfer/v1/denomtrace.proto
@@ -7,6 +7,7 @@ option go_package = "github.com/cosmos/ibc-go/v8/modules/apps/transfer/types";
 // DenomTrace contains the base denomination for ICS20 fungible tokens and the
 // source tracing information path.
 message DenomTrace {
+  option deprecated = true;
   // path defines the chain of port/channel identifiers used for tracing the
   // source of the fungible token.
   string path = 1;

From 2843f30b49c209fa2d4f7cd8b2208e6f93d9c3bb Mon Sep 17 00:00:00 2001
From: Carlos Rodriguez <carlos@interchain.io>
Date: Wed, 5 Jun 2024 23:07:14 +0200
Subject: [PATCH 4/4] Update CHANGELOG.md

---
 CHANGELOG.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 6cc509876bf..adbb891f906 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -57,7 +57,7 @@ Ref: https://keepachangelog.com/en/1.0.0/
 * (core/05-port) [\#6341](https://github.com/cosmos/ibc-go/pull/6341) Modify `UnmarshalPacketData` interface to take in the context, portID, and channelID. This allows for packet data's to be unmarshaled based on the channel version.
 * (apps/27-interchain-accounts) [\#6433](https://github.com/cosmos/ibc-go/pull/6433) Use UNORDERED as the default ordering for new ICA channels.
 * (apps/transfer) [\#6440](https://github.com/cosmos/ibc-go/pull/6440) Remove `GetPrefixedDenom`.
-* (apps/transfer) [\#6508](https://github.com/cosmos/ibc-go/pull/6508) Remove the DenomTrace type.
+* (apps/transfer) [\#6508](https://github.com/cosmos/ibc-go/pull/6508) Remove the `DenomTrace` type.
 
 ### State Machine Breaking