Building a Sovereign Rollup with BeaconKit and Rollkit

Introduction

This tutorial guides developers through the process of building and running a sovereign rollup using BeaconKit and Rollkit. BeaconKit is a modular framework for building EVM-based consensus clients, while Rollkit is a modular framework for building sovereign rollups. By combining these tools, you can create your own customizable rollup chain using the Ethereum Virtual Machine (EVM).

Prerequisites

Before you begin, ensure you have the following software installed on your machine:

Rollkit

Rollkit is a modular framework for sovereign rollups. Follow our Quick Start Guide to walk through the installation process. The installation script will install the Rollkit CLI, Golang, and jq if they are not already present on your machine.

Docker

Docker is essential for running containerized applications. Follow the provided link to install Docker on your system.

Run a local Data Availability (DA) node

First, set up a local data availability network node:

cd $HOME && curl -sSL https://rollkit.dev/install-local-da.sh | sh -s v0.3.1

This script builds and runs a DA node, which will listen on port 7980.

Clone the BeaconKit repository

Clone the BeaconKit repository and switch to the Rollkit branch:

cd $HOME
git clone -b rollkit https://github.com/rollkit/beacon-kit.git
cd beacon-kit && git checkout rollkit

Start the Go Ethereum (Geth) client

Start local ephemeral Go Ethereum client to provide the execution layer:

cd $HOME/beacon-kit
make start-geth

Notice within logs indicating that your Geth client is running the RPC server is listening on port 8545. You will need that port to deploy and interact with smart contracts on the BeaconKit EVM.

Build and run the BeaconKit node

Open a new terminal and run:

cd $HOME/beacon-kit
make start

This command builds, configures, and starts an ephemeral beacond node as a Rollkit sequencer.

You should now see output indicating that your Rollkit node is running, with log messages about creating and publishing blocks, computing state roots, and other node activities:

...
11:45AM INF indexed block events height=39 module=txindex
11:45AM INF Creating and publishing block height=40 module=BlockManager
11:45AM INF requesting beacon block assembly 🙈 module=server service=validator slot=40
11:45AM INF payload retrieved from local builder 🏗️  for_slot=40 module=server num_blobs=0 override_builder=false parent_hash=0x88081d5e4c48de2f82464f2c8b4b46df8892fe921e5e9b13113ed2a62081d843 payload_block_hash=0x2ff9329ffecc7f395cb72acb9fd81a6085e5d75101ab14b508f6418fbcd7d0b4 service=payload-builder
11:45AM INF computing state root for block 🌲 module=server service=validator slot=40
11:45AM INF state root computed for block 💻  module=server service=validator slot=40 state_root=0x5f75afde5c6a596fa11c17e8c60ca291ffb31ae5c9a40392e0ceb4d45ab42037
11:45AM INF beacon block successfully built 🛠️  duration=46.93036ms module=server service=validator slot=40 state_root=0x5f75afde5c6a596fa11c17e8c60ca291ffb31ae5c9a40392e0ceb4d45ab42037
11:45AM INF received proposal with beacon_block=true blob_sidecars=true module=baseapp service=prepare-proposal
11:45AM INF no blob sidecars to verify, skipping verifier 🧢 module=server service=blockchain slot=0x28
11:45AM INF received proposal with beacon_block=true blob_sidecars=true module=baseapp service=prepare-proposal
11:45AM INF no blob sidecars to verify, skipping verifier 🧢 module=server service=blockchain slot=0x28
11:45AM INF received incoming beacon block 📫 module=server service=blockchain state_root=0x5f75afde5c6a596fa11c17e8c60ca291ffb31ae5c9a40392e0ceb4d45ab42037
11:45AM INF calling new payload is_optimistic=false module=server payload_block_hash=0x2ff9329ffecc7f395cb72acb9fd81a6085e5d75101ab14b508f6418fbcd7d0b4 payload_parent_block_hash=0x88081d5e4c48de2f82464f2c8b4b46df8892fe921e5e9b13113ed2a62081d843 service=execution-engine
11:45AM INF state root verification succeeded - accepting incoming beacon block 🏎️ module=server service=blockchain state_root=0x5f75afde5c6a596fa11c17e8c60ca291ffb31ae5c9a40392e0ceb4d45ab42037
11:45AM INF optimistically triggering payload build for next slot 🛩️  module=server next_slot=41 service=blockchain
11:45AM INF notifying forkchoice update  finalized_eth1_hash=0x88081d5e4c48de2f82464f2c8b4b46df8892fe921e5e9b13113ed2a62081d843 has_attributes=true head_eth1_hash=0x2ff9329ffecc7f395cb72acb9fd81a6085e5d75101ab14b508f6418fbcd7d0b4 module=server safe_eth1_hash=0x88081d5e4c48de2f82464f2c8b4b46df8892fe921e5e9b13113ed2a62081d843 service=execution-engine
11:45AM WRN suggested fee recipient is not configured 🔆 fee-recipent="0x000000...000000 (20B)" module=server service=engine.client
11:45AM INF calling new payload is_optimistic=true module=server payload_block_hash=0x2ff9329ffecc7f395cb72acb9fd81a6085e5d75101ab14b508f6418fbcd7d0b4 payload_parent_block_hash=0x88081d5e4c48de2f82464f2c8b4b46df8892fe921e5e9b13113ed2a62081d843 service=execution-engine
11:45AM INF bob the builder; can we forkchoice update it?; bob the builder; yes we can 🚧 for_slot=41 head_eth1_hash=0x2ff9329ffecc7f395cb72acb9fd81a6085e5d75101ab14b508f6418fbcd7d0b4 module=server parent_block_root=0x9676648a3c292540562b082c20c4b6663986182f5d8733f84fb3f1445b66a4ce payload_id=0x03bc2b46dc4bef55 service=payload-builder
11:45AM INF finalized block block_app_hash=004216246AE7750D578035EA1C6CD13330BD91A0C3FDD628F96D514ACF691BE5 height=40 module=BlockManager num_txs_res=2 num_val_updates=0
11:45AM INF executed block app_hash=004216246AE7750D578035EA1C6CD13330BD91A0C3FDD628F96D514ACF691BE5 height=40 module=BlockManager
11:45AM INF notifying forkchoice update  finalized_eth1_hash=0x88081d5e4c48de2f82464f2c8b4b46df8892fe921e5e9b13113ed2a62081d843 has_attributes=false head_eth1_hash=0x2ff9329ffecc7f395cb72acb9fd81a6085e5d75101ab14b508f6418fbcd7d0b4 module=server safe_eth1_hash=0x88081d5e4c48de2f82464f2c8b4b46df8892fe921e5e9b13113ed2a62081d843 service=execution-engine
11:45AM INF indexed block events height=40 module=txindex
11:45AM INF successfully refreshed engine auth token module=server service=engine.client
11:45AM INF Creating and publishing block height=41 module=BlockManager
...

Smart Contract Deployment and Interaction

To deploy and interact with smart contracts on the BeaconKit EVM, you can use the tools you are already familiar with, follow our Contract interaction tutorial to get a hands on experience.

To fund your account with some tokens, modify a Geth genesis file and restart the Geth client: Open $HOME/beacon-kit/testing/files/eth-genesis.json, and add your account address and balance:

"nonce": "0x0000000000000000",
"timestamp": "0x0",
"alloc": {
  "<your address>": { // [!code focus]
    "balance": "0x12345000000000000000000" // [!code focus]
  }, // [!code focus]
  "0x20f33ce90a13a4b5e7697e3544c3083b8f8a51d4": {
    "balance": "0x123450000000000000000"
  },

Conclusion

Congratulations! You've successfully set up a BeaconKit node using Rollkit, creating your own sovereign rollup. This setup demonstrates the basic functionality of combining BeaconKit with Rollkit.

Next Steps

To further customize your rollup chain:

1. Experiment with different Rollkit settings to optimize performance.
2. Consider implementing custom smart contracts on your rollup.
3. Test the scalability and performance of your rollup under various conditions.

Troubleshooting

If you encounter issues:

• Ensure all prerequisites are correctly installed and up to date.
• Check that your local DA node is running correctly on port 7980.
• Verify that the Geth client is properly initialized and running.
• Review the BeaconKit logs for any specific error messages.

For more detailed information and updates, visit the BeaconKit GitHub repository and the Rollkit documentation.