How to create a genesis for your rollup

This guide will walk you through the process of setting up a genesis for your rollup. Follow the steps below to initialize your rollup chain, add a genesis account, and start the chain.

0. Pre-requisities

For this guide you need to have a chain directory where you have created and built your chain.

If you don't have a chain directory yet, you can initialize a simple ignite chain by following this guide

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This guide will use the simple ignite chain created in linked guide. Make sure to update any relevant variables to match your chain.

1. Setting variables

First, set the necessary variables for your chain in the terminal, here is an example:

VALIDATOR_NAME=validator1
CHAIN_ID=gm
KEY_NAME=rollup-key
CHAINFLAG="--chain-id ${CHAIN_ID}"
TOKEN_AMOUNT="10000000000000000000000000stake"
STAKING_AMOUNT="1000000000stake"

2. Rebuild your chain

Ensure that rollkit.toml is present in the root of your rollup directory (if not, follow a Guide to set it up) and run the following command to (re)generate an entrypoint binary out of the code:

rollkit rebuild

This (re)creates an entrypoint binary in the root of your rollup directory. which is used to run all the operations on the rollup chain.

Ensure that the chain configuration directory is set correctly in the rollkit.toml file.

For example:

[chain]
  config_dir = "/Users/you/.gm"

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You can always recreate the rollkit.toml file by deleting it and re-running the following command:

rollkit toml init

3. Resetting existing genesis/chain data

Reset any existing chain data:

rollkit tendermint unsafe-reset-all

Reset any existing genesis data:

rm -rf $HOME/.$CHAIN_ID/config/gentx
rm $HOME/.$CHAIN_ID/config/genesis.json

4. Initializing the validator

Initialize the validator with the chain ID you set:

rollkit init $VALIDATOR_NAME --chain-id $CHAIN_ID

5. Adding a key to keyring backend

Add a key to the keyring-backend:

rollkit keys add $KEY_NAME --keyring-backend test

6. Adding a genesis account

Add a genesis account with the specified token amount:

rollkit genesis add-genesis-account $KEY_NAME $TOKEN_AMOUNT --keyring-backend test

7. Setting the staking amount in the genesis transaction

Set the staking amount in the genesis transaction:

rollkit genesis gentx $KEY_NAME $STAKING_AMOUNT --chain-id $CHAIN_ID --keyring-backend test

8. Collecting genesis transactions

Collect the genesis transactions:

rollkit genesis collect-gentxs

9. Configuring the genesis file

Copy the centralized sequencer address into genesis.json:

ADDRESS=$(jq -r '.address' ~/.$CHAIN_ID/config/priv_validator_key.json)
PUB_KEY=$(jq -r '.pub_key' ~/.$CHAIN_ID/config/priv_validator_key.json)
jq --argjson pubKey "$PUB_KEY" '.consensus["validators"]=[{"address": "'$ADDRESS'", "pub_key": $pubKey, "power": "1000", "name": "Rollkit Sequencer"}]' ~/.$CHAIN_ID/config/genesis.json > temp.json && mv temp.json ~/.$CHAIN_ID/config/genesis.json

10. Starting the chain

Finally, start the chain with your start command.

For example, start the simple ignite chain with the following command:

rollkit start --rollkit.aggregator --rollkit.sequencer_rollup_id $CHAIN_ID

Summary

By following these steps, you will set up the genesis for your rollup, initialize the validator, add a genesis account, and started the chain. This guide provides a basic framework for configuring and starting your rollup using the Rollkit CLI. Make sure rollkit.toml is present in the root of your rollup directory, and use the rollkit command for all operations.