block-sdk/lanes/base

🏗️ Default Lane Setup

📦 Dependencies

The Block SDK is built on top of the Cosmos SDK. The Block SDK is currently compatible with Cosmos SDK versions greater than or equal to v0.47.0.

📥 Installation

To install the Block SDK, run the following command:

$ go install github.com/skip-mev/block-sdk

📚 Usage

1. First determine the set of lanes that you want to use in your application. The available lanes can be found in our Lane App Store. This guide only sets up the default lane
2. In your base application, you will need to create a LanedMempool composed of the lanes you want to use.
3. Next, order the lanes by priority. The first lane is the highest priority lane and the last lane is the lowest priority lane. It is recommended that the last lane is the default lane.
4. You will also need to create a PrepareProposalHandler and a ProcessProposalHandler that will be responsible for preparing and processing proposals respectively. Configure the order of the lanes in the PrepareProposalHandler and ProcessProposalHandler to match the order of the lanes in the LanedMempool.
5. Configure your app.go to include the following:

import (
    "github.com/skip-mev/block-sdk/abci"
    "github.com/skip-mev/block-sdk/block/base"
    defaultlane "github.com/skip-mev/block-sdk/lanes/base"
)

...

func NewApp() {
    ...
    // 1. Create the lanes.
    //
    // NOTE: The lanes are ordered by priority. The first lane is the highest priority
    // lane and the last lane is the lowest priority lane. Top of block lane allows
    // transactions to bid for inclusion at the top of the next block.
    //
    // For more information on how to utilize the LaneConfig please
    // visit the README in docs.skip.money/chains/lanes/build-your-own-lane#-lane-config.
    //
    // Default lane accepts all transactions.
    defaultConfig := base.LaneConfig{
        Logger:        app.Logger(),
        TxEncoder:     app.txConfig.TxEncoder(),
        TxDecoder:     app.txConfig.TxDecoder(),
        MaxBlockSpace: math.LegacyZeroDec(),
        MaxTxs:        0,
    }
    defaultLane := defaultlane.NewDefaultLane(defaultConfig)

    // 2. Set up the relative priority of lanes
    lanes := []block.Lane{
        defaultLane,
    }
    mempool := block.NewLanedMempool(app.Logger(), true, lanes...)
    app.App.SetMempool(mempool)

    ...

    // 3. Set up the ante handler. 
    anteDecorators := []sdk.AnteDecorator{
		ante.NewSetUpContextDecorator(),
        ...
		utils.NewIgnoreDecorator(
			ante.NewDeductFeeDecorator(
				options.BaseOptions.AccountKeeper,
				options.BaseOptions.BankKeeper,
				options.BaseOptions.FeegrantKeeper,
				options.BaseOptions.TxFeeChecker,
			),
			options.FreeLane,
		),
        ...
	}

    anteHandler := sdk.ChainAnteDecorators(anteDecorators...)

    // Set the lane ante handlers on the lanes.
    //
    // NOTE: This step is very important. Without the antehandlers, lanes will not
    // be able to verify transactions.
    for _, lane := range lanes {
        lane.SetAnteHandler(anteHandler)
    }
    app.App.SetAnteHandler(anteHandler)

    // 4. Set the abci handlers on base app
    proposalHandler := abci.NewProposalHandler(
        app.Logger(),
        app.TxConfig().TxDecoder(),
        mempool,
    )
    app.App.SetPrepareProposal(proposalHandler.PrepareProposalHandler())
    app.App.SetProcessProposal(proposalHandler.ProcessProposalHandler())

    ...
}