> ## Documentation Index > Fetch the complete documentation index at: https://docs.cosmos.network/llms.txt > Use this file to discover all available pages before exploring further. # IBC-Go v8.1 to v10 > This guide provides instructions for migrating to a new version of ibc-go. This guide provides instructions for migrating to a new version of ibc-go. **Note:** ibc-go supports golang semantic versioning and therefore all imports must be updated on major version releases. In addition, for this release, the 08-wasm module has been released as v10, and the callbacks middleware has been moved into the ibc-go module itself. Diff examples are shown after the list of overall changes: * To add support for IBC v2, Chains will need to wire up a new IBC v2 Transfer stack * Chains will need to wire up the new light client modules * Chains will need to update Keeper construction calls to comply with the new signatures * Chains will need to remove the route for the legacy proposal handler for 02-client from their `app/app.go` * Chains will need to remove the capability keeper and all related setup, including the scoped keepers from their `app/app.go` * Chains will need to remove ibc fee middleware (29-fee) * Chains will need, if using this module, to update their imports and usage of `github.com/cosmos/ibc-go/modules/light-clients/08-wasm/` to `github.com/cosmos/ibc-go/modules/light-clients/08-wasm/v10` * Chains will need, if using this module, to update their imports and usage of `github.com/cosmos/ibc-go/modules/apps/callbacks` to `github.com/cosmos/ibc-go/v10/modules/apps/callbacks` To add IBC v2 support, wire up a new transfer stack. Example below showing wired up with IBC Callbacks module: ```diff theme={"theme":{"light":"github-light-high-contrast","dark":"github-dark-high-contrast"}} + var ibcv2TransferStack ibcapi.IBCModule + ibcv2TransferStack = transferv2.NewIBCModule(app.TransferKeeper) + ibcv2TransferStack = ibccallbacksv2.NewIBCMiddleware( + transferv2.NewIBCModule(app.TransferKeeper), + app.IBCKeeper.ChannelKeeperV2, + wasmStackIBCHandler, + app.IBCKeeper.ChannelKeeperV2, + maxCallbackGas, + ) ``` Wire up each light client as a separate module and add them to the client keeper router. Example below for 07-tendermint and 08-wasm: ```diff theme={"theme":{"light":"github-light-high-contrast","dark":"github-dark-high-contrast"}} + / Light client modules + clientKeeper := app.IBCKeeper.ClientKeeper + storeProvider := app.IBCKeeper.ClientKeeper.GetStoreProvider() + + tmLightClientModule := ibctm.NewLightClientModule(appCodec, storeProvider) + clientKeeper.AddRoute(ibctm.ModuleName, &tmLightClientModule) + + wasmLightClientModule := ibcwasm.NewLightClientModule(app.WasmClientKeeper, storeProvider) + clientKeeper.AddRoute(ibcwasmtypes.ModuleName, &wasmLightClientModule) ``` Remove ibc fee module name (if used) from module account permissions: ```diff theme={"theme":{"light":"github-light-high-contrast","dark":"github-dark-high-contrast"}} / app.go ... / module account permissions var maccPerms = map[string][]string{ ... - ibcfeetypes.ModuleName: nil, ... } ``` Remove `CapabilityKeeper`, `IBCFeeKeeper` and all `capabilitykeeper.ScopedKeeper` Scoped keepers from the App struct: ```diff expandable theme={"theme":{"light":"github-light-high-contrast","dark":"github-dark-high-contrast"}} / ChainApp extended ABCI application type ChainApp struct { ... - CapabilityKeeper *capabilitykeeper.Keeper ... - IBCFeeKeeper ibcfeekeeper.Keeper ... - ScopedIBCKeeper capabilitykeeper.ScopedKeeper - ScopedICAHostKeeper capabilitykeeper.ScopedKeeper - ScopedICAControllerKeeper capabilitykeeper.ScopedKeeper - ScopedTransferKeeper capabilitykeeper.ScopedKeeper - ScopedIBCFeeKeeper capabilitykeeper.ScopedKeeper ... } ... - app.ScopedIBCKeeper = scopedIBCKeeper - app.ScopedTransferKeeper = scopedTransferKeeper - app.ScopedWasmKeeper = scopedWasmKeeper - app.ScopedICAHostKeeper = scopedICAHostKeeper - app.ScopedICAControllerKeeper = scopedICAControllerKeeper ``` Remove capability and ibc fee middleware store keys from the `NewKVStoreKeys` call: ```diff theme={"theme":{"light":"github-light-high-contrast","dark":"github-dark-high-contrast"}} ... keys := storetypes.NewKVStoreKeys( ... - capabilitytypes.StoreKey, - ibcfeetypes.StoreKey, ... } ``` Remove the in-memory store keys previously used by the capability module: ```diff theme={"theme":{"light":"github-light-high-contrast","dark":"github-dark-high-contrast"}} - memKeys := storetypes.NewMemoryStoreKeys(capabilitytypes.MemStoreKey) ... - app.MountMemoryStores(memKeys) ``` Remove creation of the capability keeper: ```diff expandable theme={"theme":{"light":"github-light-high-contrast","dark":"github-dark-high-contrast"}} - / add capability keeper and ScopeToModule for ibc module - app.CapabilityKeeper = capabilitykeeper.NewKeeper( - appCodec, - keys[capabilitytypes.StoreKey], - memKeys[capabilitytypes.MemStoreKey], - ) - scopedIBCKeeper := app.CapabilityKeeper.ScopeToModule(ibcexported.ModuleName) - scopedICAHostKeeper := app.CapabilityKeeper.ScopeToModule(icahosttypes.SubModuleName) - scopedICAControllerKeeper := app.CapabilityKeeper.ScopeToModule(icacontrollertypes.SubModuleName) - scopedTransferKeeper := app.CapabilityKeeper.ScopeToModule(ibctransfertypes.ModuleName) - scopedWasmKeeper := app.CapabilityKeeper.ScopeToModule(wasmtypes.ModuleName) - app.CapabilityKeeper.Seal() ``` Remove the legacy route for the client keeper: ```diff theme={"theme":{"light":"github-light-high-contrast","dark":"github-dark-high-contrast"}} ... govRouter.AddRoute(govtypes.RouterKey, govv1beta1.ProposalHandler). - AddRoute(paramproposal.RouterKey, params.NewParamChangeProposalHandler(app.ParamsKeeper)). - AddRoute(ibcclienttypes.RouterKey, ibcclient.NewClientProposalHandler(app.IBCKeeper.ClientKeeper)) + AddRoute(paramproposal.RouterKey, params.NewParamChangeProposalHandler(app.ParamsKeeper)) ``` Update Core IBC Keeper constructor: ```diff theme={"theme":{"light":"github-light-high-contrast","dark":"github-dark-high-contrast"}} app.IBCKeeper = ibckeeper.NewKeeper( appCodec, - keys[ibcexported.StoreKey], + runtime.NewKVStoreService(keys[ibcexported.StoreKey]), app.GetSubspace(ibcexported.ModuleName), - app.StakingKeeper, app.UpgradeKeeper, - scopedIBCKeeper, authtypes.NewModuleAddress(govtypes.ModuleName).String(), ) ``` Update IBC Transfer keeper constructor: ```diff expandable theme={"theme":{"light":"github-light-high-contrast","dark":"github-dark-high-contrast"}} app.TransferKeeper = ibctransferkeeper.NewKeeper( appCodec, - keys[ibctransfertypes.StoreKey], + runtime.NewKVStoreService(keys[ibctransfertypes.StoreKey]), app.GetSubspace(ibctransfertypes.ModuleName), app.IBCKeeper.ChannelKeeper, app.IBCKeeper.ChannelKeeper, - app.IBCKeeper.PortKeeper, + app.MsgServiceRouter(), app.AccountKeeper, app.BankKeeper, - scopedTransferKeeper, authtypes.NewModuleAddress(govtypes.ModuleName).String(), ) ``` Update ICA Host keeper constructor, notice the removal of the `WithQueryRouter` call in particular: ```diff expandable theme={"theme":{"light":"github-light-high-contrast","dark":"github-dark-high-contrast"}} app.ICAHostKeeper = icahostkeeper.NewKeeper( appCodec, - keys[icahosttypes.StoreKey], + runtime.NewKVStoreService(keys[icahosttypes.StoreKey]), app.GetSubspace(icahosttypes.SubModuleName), - app.IBCFeeKeeper, / use ics29 fee as ics4Wrapper in middleware stack app.IBCKeeper.ChannelKeeper, - app.IBCKeeper.PortKeeper, + app.IBCKeeper.ChannelKeeper, app.AccountKeeper, - scopedICAHostKeeper, app.MsgServiceRouter(), + app.GRPCQueryRouter(), authtypes.NewModuleAddress(govtypes.ModuleName).String(), ) - app.ICAHostKeeper.WithQueryRouter(app.GRPCQueryRouter()) ``` Remove IBC Fee Module keeper: ```diff theme={"theme":{"light":"github-light-high-contrast","dark":"github-dark-high-contrast"}} - app.IBCFeeKeeper = ibcfeekeeper.NewKeeper( - appCodec, keys[ibcfeetypes.StoreKey], - app.IBCKeeper.ChannelKeeper, / may be replaced with IBC middleware - app.IBCKeeper.ChannelKeeper, - app.IBCKeeper.PortKeeper, app.AccountKeeper, app.BankKeeper, - ) ``` Update Transfer stack to remove the fee middleware. The example below shows the correct way to wire up a middleware stack with the IBC callbacks middleware: ```diff expandable theme={"theme":{"light":"github-light-high-contrast","dark":"github-dark-high-contrast"}} / Create Transfer Stack var transferStack porttypes.IBCModule transferStack = transfer.NewIBCModule(app.TransferKeeper) - transferStack = ibccallbacks.NewIBCMiddleware(transferStack, app.IBCFeeKeeper, wasmStackIBCHandler, maxCallbackGas) - transferStack = ibcfee.NewIBCMiddleware(transferStack, app.IBCFeeKeeper) + / callbacks wraps the transfer stack as its base app, and uses PacketForwardKeeper as the ICS4Wrapper + / i.e. packet-forward-middleware is higher on the stack and sits between callbacks and the ibc channel keeper + / Since this is the lowest level middleware of the transfer stack, it should be the first entrypoint for transfer keeper's + / WriteAcknowledgement. + cbStack := ibccallbacks.NewIBCMiddleware(transferStack, app.PacketForwardKeeper, wasmStackIBCHandler, maxCallbackGas) transferStack = packetforward.NewIBCMiddleware( - transferStack, + cbStack, app.PacketForwardKeeper, 0, packetforwardkeeper.DefaultForwardTransferPacketTimeoutTimestamp, ) + app.TransferKeeper.WithICS4Wrapper(cbStack) ``` Remove ibc fee middleware and any empty IBCModule (often dubbed `noAuthzModule`) from the ICA Controller stack creation: ```diff theme={"theme":{"light":"github-light-high-contrast","dark":"github-dark-high-contrast"}} - var noAuthzModule porttypes.IBCModule - icaControllerStack = icacontroller.NewIBCMiddleware(noAuthzModule, app.ICAControllerKeeper) - icaControllerStack = ibcfee.NewIBCMiddleware(icaControllerStack, app.IBCFeeKeeper) + icaControllerStack = icacontroller.NewIBCMiddleware(app.ICAControllerKeeper) ``` Remove ibc fee middleware from ICA Host stack creation: ```diff theme={"theme":{"light":"github-light-high-contrast","dark":"github-dark-high-contrast"}} icaHostStack = icahost.NewIBCModule(app.ICAHostKeeper) - icaHostStack = ibcfee.NewIBCMiddleware(icaHostStack, app.IBCFeeKeeper) ``` Update the module manager creation by removing the capability module, fee module and updating the tendermint app module constructor: ```diff theme={"theme":{"light":"github-light-high-contrast","dark":"github-dark-high-contrast"}} app.ModuleManager = module.NewManager( ... - capability.NewAppModule(appCodec, *app.CapabilityKeeper, false), ... - ibcfee.NewAppModule(app.IBCFeeKeeper), ... - ibctm.NewAppModule(), + ibctm.NewAppModule(tmLightClientModule), ... ) ``` Remove the capability module and ibc fee middleware from `SetOrderBeginBlockers`, `SetOrderEndBlockers`, `SetOrderInitGenesis` and `SetOrderExportGenesis`: ```diff theme={"theme":{"light":"github-light-high-contrast","dark":"github-dark-high-contrast"}} - capabilitytypes.ModuleName, - ibcfeetypes.ModuleName, ``` If you use 08-wasm, you will need to update the go module that is used for `QueryPlugins` and `AcceptListStargateQuerier`. ```diff theme={"theme":{"light":"github-light-high-contrast","dark":"github-dark-high-contrast"}} - wasmLightClientQuerier := ibcwasmtypes.QueryPlugins{ + wasmLightClientQuerier := ibcwasmkeeper.QueryPlugins{ - Stargate: ibcwasmtypes.AcceptListStargateQuerier([]string{ + Stargate: ibcwasmkeeper.AcceptListStargateQuerier([]string{ "/ibc.core.client.v1.Query/ClientState", "/ibc.core.client.v1.Query/ConsensusState", "/ibc.core.connection.v1.Query/Connection", - }), + }, app.GRPCQueryRouter()), } ``` If you use 08-wasm, you will need to use the wasm client keeper rather than the go module to initialize pinned codes: ```diff theme={"theme":{"light":"github-light-high-contrast","dark":"github-dark-high-contrast"}} - if err := ibcwasmkeeper.InitializePinnedCodes(ctx); err != nil { - panic(fmt.Sprintf("ibcwasmkeeper failed initialize pinned codes %s", err)) + if err := app.WasmClientKeeper.InitializePinnedCodes(ctx); err != nil { + panic(fmt.Sprintf("WasmClientKeeper failed initialize pinned codes %s", err)) + } ```