initial build and existing tests pass

modules/apps/callbacks/testing/simapp/app.go

@@ -390,6 +390,8 @@ func NewSimApp(
 		appCodec, runtime.NewKVStoreService(keys[ibctransfertypes.StoreKey]), app.GetSubspace(ibctransfertypes.ModuleName),
 		app.IBCFeeKeeper, // ISC4 Wrapper: fee IBC middleware
 		app.IBCKeeper.ChannelKeeper,
+		app.IBCKeeper.ChannelKeeperV2,
+		app.IBCKeeper.ClientV2Keeper,
 		app.AccountKeeper, app.BankKeeper,
 		authtypes.NewModuleAddress(govtypes.ModuleName).String(),
 	)

modules/apps/transfer/keeper/keeper.go

@@ -30,11 +30,12 @@ type Keeper struct {
 	cdc            codec.BinaryCodec
 	legacySubspace types.ParamSubspace
 
-	ics4Wrapper   porttypes.ICS4Wrapper
-	channelKeeper types.ChannelKeeper
-
-	AuthKeeper types.AccountKeeper
-	BankKeeper types.BankKeeper
+	ics4Wrapper     porttypes.ICS4Wrapper
+	channelKeeper   types.ChannelKeeper
+	channelKeeperV2 types.ChannelKeeperV2
+	clientKeeperV2  types.ClientKeeperV2
+	AuthKeeper      types.AccountKeeper
+	BankKeeper      types.BankKeeper
 
 	// the address capable of executing a MsgUpdateParams message. Typically, this
 	// should be the x/gov module account.
@@ -48,6 +49,8 @@ func NewKeeper(
 	legacySubspace types.ParamSubspace,
 	ics4Wrapper porttypes.ICS4Wrapper,
 	channelKeeper types.ChannelKeeper,
+	channelKeeperV2 types.ChannelKeeperV2,
+	clientKeeperV2 types.ClientKeeperV2,
 	authKeeper types.AccountKeeper,
 	bankKeeper types.BankKeeper,
 	authority string,
@@ -62,14 +65,16 @@ func NewKeeper(
 	}
 
 	return Keeper{
-		cdc:            cdc,
-		storeService:   storeService,
-		legacySubspace: legacySubspace,
-		ics4Wrapper:    ics4Wrapper,
-		channelKeeper:  channelKeeper,
-		AuthKeeper:     authKeeper,
-		BankKeeper:     bankKeeper,
-		authority:      authority,
+		cdc:             cdc,
+		storeService:    storeService,
+		legacySubspace:  legacySubspace,
+		ics4Wrapper:     ics4Wrapper,
+		channelKeeper:   channelKeeper,
+		channelKeeperV2: channelKeeperV2,
+		clientKeeperV2:  clientKeeperV2,
+		AuthKeeper:      authKeeper,
+		BankKeeper:      bankKeeper,
+		authority:       authority,
 	}
 }
 

modules/apps/transfer/keeper/keeper_test.go

@@ -60,6 +60,8 @@ func (suite *KeeperTestSuite) TestNewKeeper() {
 				suite.chainA.GetSimApp().GetSubspace(types.ModuleName),
 				suite.chainA.GetSimApp().IBCKeeper.ChannelKeeper,
 				suite.chainA.GetSimApp().IBCKeeper.ChannelKeeper,
+				suite.chainA.GetSimApp().IBCKeeper.ChannelKeeperV2,
+				suite.chainA.App.GetIBCKeeper().ClientV2Keeper,
 				suite.chainA.GetSimApp().AccountKeeper,
 				suite.chainA.GetSimApp().BankKeeper,
 				suite.chainA.GetSimApp().ICAControllerKeeper.GetAuthority(),
@@ -72,6 +74,8 @@ func (suite *KeeperTestSuite) TestNewKeeper() {
 				suite.chainA.GetSimApp().GetSubspace(types.ModuleName),
 				suite.chainA.GetSimApp().IBCKeeper.ChannelKeeper,
 				suite.chainA.GetSimApp().IBCKeeper.ChannelKeeper,
+				suite.chainA.GetSimApp().IBCKeeper.ChannelKeeperV2,
+				suite.chainA.App.GetIBCKeeper().ClientV2Keeper,
 				authkeeper.AccountKeeper{}, // empty account keeper
 				suite.chainA.GetSimApp().BankKeeper,
 				suite.chainA.GetSimApp().ICAControllerKeeper.GetAuthority(),
@@ -84,6 +88,8 @@ func (suite *KeeperTestSuite) TestNewKeeper() {
 				suite.chainA.GetSimApp().GetSubspace(types.ModuleName),
 				suite.chainA.GetSimApp().IBCKeeper.ChannelKeeper,
 				suite.chainA.GetSimApp().IBCKeeper.ChannelKeeper,
+				suite.chainA.GetSimApp().IBCKeeper.ChannelKeeperV2,
+				suite.chainA.App.GetIBCKeeper().ClientV2Keeper,
 				suite.chainA.GetSimApp().AccountKeeper,
 				suite.chainA.GetSimApp().BankKeeper,
 				"", // authority

modules/apps/transfer/keeper/msg_server.go

@@ -10,9 +10,10 @@ import (
 	"github.com/cosmos/ibc-go/v9/modules/apps/transfer/internal/events"
 	"github.com/cosmos/ibc-go/v9/modules/apps/transfer/internal/telemetry"
 	"github.com/cosmos/ibc-go/v9/modules/apps/transfer/types"
+	clienttypesv2 "github.com/cosmos/ibc-go/v9/modules/core/02-client/v2/types"
 	channeltypes "github.com/cosmos/ibc-go/v9/modules/core/04-channel/types"
+	channeltypesv2 "github.com/cosmos/ibc-go/v9/modules/core/04-channel/v2/types"
 	ibcerrors "github.com/cosmos/ibc-go/v9/modules/core/errors"
-	"github.com/cosmos/ibc-go/v9/modules/core/exported"
 )
 
 var _ types.MsgServer = (*Keeper)(nil)
@@ -30,19 +31,22 @@ func (k Keeper) Transfer(goCtx context.Context, msg *types.MsgTransfer) (*types.
 		return nil, err
 	}
 
-	// if a channel exists with source channel, then use IBC V1 protocol
-	// otherwise use IBC V2 protocol
+	// if a eurela counterparty exists with source channel, then use IBC V2 protocol
+	// otherwise use IBC V1 protocol
 	var (
-		channel channeltypes.Channel
-		isV1    bool
-		client  exported.ClientState
-		isV2    bool
+		channel            channeltypes.Channel
+		counterparty       clienttypesv2.CounterpartyInfo
+		isIBCV2            bool
+		destinationPort    string
+		destinationChannel string
 	)
-	channel, isV1 = k.channelKeeper.GetChannel(ctx, msg.SourcePort, msg.SourceChannel)
-
-	appVersion, found := k.ics4Wrapper.GetAppVersion(ctx, msg.SourcePort, msg.SourceChannel)
-	if !found {
-		return nil, errorsmod.Wrapf(ibcerrors.ErrInvalidRequest, "application version not found for source port: %s and source channel: %s", msg.SourcePort, msg.SourceChannel)
+	counterparty, isIBCV2 = k.clientKeeperV2.GetClientCounterparty(ctx, msg.SourceChannel)
+	if !isIBCV2 {
+		var found bool
+		channel, found = k.channelKeeper.GetChannel(ctx, msg.SourcePort, msg.SourceChannel)
+		if !found {
+			return nil, errorsmod.Wrapf(channeltypes.ErrChannelNotFound, "port ID (%s) channel ID (%s)", msg.SourcePort, msg.SourceChannel)
+		}
 	}
 
 	coin := msg.Token
@@ -60,26 +64,56 @@ func (k Keeper) Transfer(goCtx context.Context, msg *types.MsgTransfer) (*types.
 		return nil, err
 	}
 
-	if err := k.SendTransfer(ctx, msg.SourcePort, msg.SourceChannel, token, sender); err != nil {
-		return nil, err
-	}
+	packetData := types.NewFungibleTokenPacketData(token.Denom.Path(), token.Amount, sender.String(), msg.Receiver, msg.Memo)
 
-	packetDataBytes, err := createPacketDataBytesFromVersion(
-		appVersion, sender.String(), msg.Receiver, msg.Memo, token,
-	)
-	if err != nil {
-		return nil, err
+	if err := packetData.ValidateBasic(); err != nil {
+		return nil, errorsmod.Wrapf(err, "failed to validate %s packet data", types.V1)
 	}
 
-	sequence, err := k.ics4Wrapper.SendPacket(ctx, msg.SourcePort, msg.SourceChannel, msg.TimeoutHeight, msg.TimeoutTimestamp, packetDataBytes)
-	if err != nil {
-		return nil, err
-	}
+	var sequence uint64
+	if isIBCV2 {
+		data, err := types.MarshalPacketData(packetData, types.V1, msg.Encoding)
+		if err != nil {
+			return nil, err
+		}
+		payload := channeltypesv2.NewPayload(
+			types.PortID, types.PortID,
+			types.V1, msg.Encoding, data,
+		)
+		msg := channeltypesv2.NewMsgSendPacket(
+			msg.SourceChannel, msg.TimeoutTimestamp,
+			sender.String(), payload,
+		)
+		res, err := k.channelKeeperV2.SendPacket(ctx, msg)
+		if err != nil {
+			return nil, err
+		}
+		sequence = res.Sequence
+		destinationPort = types.PortID
+		destinationChannel = counterparty.ClientId
+	} else {
 
-	events.EmitTransferEvent(ctx, sender.String(), msg.Receiver, token, msg.Memo)
+		if err := k.SendTransfer(ctx, msg.SourcePort, msg.SourceChannel, token, sender); err != nil {
+			return nil, err
+		}
+
+		packetDataBytes, err := createPacketDataBytesFromVersion(
+			types.V1, sender.String(), msg.Receiver, msg.Memo, token,
+		)
+		if err != nil {
+			return nil, err
+		}
+
+		sequence, err = k.ics4Wrapper.SendPacket(ctx, msg.SourcePort, msg.SourceChannel, msg.TimeoutHeight, msg.TimeoutTimestamp, packetDataBytes)
+		if err != nil {
+			return nil, err
+		}
+
+		events.EmitTransferEvent(ctx, sender.String(), msg.Receiver, token, msg.Memo)
+		destinationPort = channel.Counterparty.PortId
+		destinationChannel = channel.Counterparty.ChannelId
+	}
 
-	destinationPort := channel.Counterparty.PortId
-	destinationChannel := channel.Counterparty.ChannelId
 	telemetry.ReportTransfer(msg.SourcePort, msg.SourceChannel, destinationPort, destinationChannel, token)
 
 	k.Logger(ctx).Info("IBC fungible token transfer", "token", coin, "sender", msg.Sender, "receiver", msg.Receiver)

modules/apps/transfer/types/expected_keepers.go

@@ -7,9 +7,10 @@ import (
 	banktypes "github.com/cosmos/cosmos-sdk/x/bank/types"
 	paramtypes "github.com/cosmos/cosmos-sdk/x/params/types"
 
+	clienttypes "github.com/cosmos/ibc-go/v9/modules/core/02-client/v2/types"
 	connectiontypes "github.com/cosmos/ibc-go/v9/modules/core/03-connection/types"
 	channeltypes "github.com/cosmos/ibc-go/v9/modules/core/04-channel/types"
-	ibcexported "github.com/cosmos/ibc-go/v9/modules/core/exported"
+	channeltypesv2 "github.com/cosmos/ibc-go/v9/modules/core/04-channel/v2/types"
 )
 
 // AccountKeeper defines the contract required for account APIs.
@@ -41,9 +42,14 @@ type ChannelKeeper interface {
 	HasChannel(ctx context.Context, portID, channelID string) bool
 }
 
+// ChannelKeeperV2 defines the expected IBC channelV2 keeper
+type ChannelKeeperV2 interface {
+	SendPacket(ctx context.Context, msg *channeltypesv2.MsgSendPacket) (*channeltypesv2.MsgSendPacketResponse, error)
+}
+
 // ClientKeeper defines the expected IBC client keeper
-type ClientKeeper interface {
-	GetClientConsensusState(ctx sdk.Context, clientID string) (connection ibcexported.ConsensusState, found bool)
+type ClientKeeperV2 interface {
+	GetClientCounterparty(ctx sdk.Context, clientID string) (counterparty clienttypes.CounterpartyInfo, found bool)
 }
 
 // ConnectionKeeper defines the expected IBC connection keeper