Deploying a rollup to Celestia ​

🌞 Introduction ​

This tutorial serves as a comprehensive guide for deploying your rollup on Celestia's data availability (DA) network. From the Rollkit perspective, there's no difference in posting blocks to Celestia's testnets or Mainnet Beta.

Before proceeding, ensure that you have completed the GM world rollup tutorial, which covers setting up a local sovereign gm-world rollup and connecting it to a local DA node.

🪶 Running a Celestia light node ​

Before you can start your rollup node, you need to initiate, sync, and possibly fund a light node on one of Celestia's networks:

• Arabica Devnet
• Mocha Testnet
• Mainnet Beta

The main difference lies in how you fund your wallet address: using testnet TIA or TIA for Mainnet Beta.

After successfully starting a light node, it's time to start posting the batches of blocks of data that your rollup generates to Celestia.

🏗️ Prerequisites ​

From the GM world rollup tutorial, you should already have the rollkit CLI and ignite CLI installed.

🏗️ Building your sovereign rollup ​

Remove the existing gm project and create a new one using ignite:

cd $HOME && rm -rf gm
ignite scaffold chain gm --address-prefix gm --no-module

Install the Rollkit app to ignite:

cd $HOME/gm
ignite app install github.com/ignite/apps/rollkit@rollkit/v0.2.1

Add the Rollkit app:

ignite rollkit add

Initialize the Rollkit chain configuration:

ignite rollkit init

This will create a $HOME/.gm directory with the chain configuration files.

🧰 Configuring your sovereign rollup ​

From the $HOME/gm directory, generate a rollkit.toml file by running:

rollkit toml init

The output should be similar to this ($HOME in the below example is /root):

Found rollup entrypoint: /root/gm/cmd/gmd/main.go, adding to rollkit.toml
Found rollup configuration under /root/.gm, adding to rollkit.toml
Initialized rollkit.toml file in the current directory.

🛠️ Configuring flags for DA ​

Now, we're prepared to initiate our rollup and establish a connection with the Celestia light node. The rollkit start command requires three DA configuration flags:

• --rollkit.da_start_height
• --rollkit.da_auth_token
• --rollkit.da_namespace

Let's determine which values to provide for each of them.

First, let's query the DA layer start height using an RPC endpoint provided by Celestia's documentation.

Let's determine what to provide for each of them.

• Mocha testnet: https://rpc-mocha.pops.one/block
• Mainnet Beta: https://rpc.lunaroasis.net/block

Here is an example for the Mocha testnet (replace URL for Mainnet Beta accordingly):

DA_BLOCK_HEIGHT=$(curl https://rpc-mocha.pops.one/block | jq -r '.result.block.header.height')
echo -e "\n Your DA_BLOCK_HEIGHT is $DA_BLOCK_HEIGHT \n"

The output of the command above will look similar to this:

Your DA_BLOCK_HEIGHT is 1777655

Now, let's obtain the authentication token of your light node using the following command (omit the --p2p.network flag for Mainnet Beta):

AUTH_TOKEN=$(celestia light auth write --p2p.network mocha)
echo -e "\n Your DA AUTH_TOKEN is $AUTH_TOKEN \n"

The output of the command above will look similar to this:

Your DA AUTH_TOKEN is eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJBbGxvdyI6WyJwdWJsaWMiLCJyZWFkIiwid3JpdGUiXX0.cSrJjpfUdTNFtzGho69V0D_8kyECn9Mzv8ghJSpKRDE

Lastly, let's set up the namespace to be used for posting data on Celestia:

DA_NAMESPACE=00000000000000000000000000000000000000000008e5f679bf7116cb

openssl rand -hex 10

🔥 Running your rollup connected to Celestia light node ​

Finally, let's initiate the rollup node with all the flags:

rollkit start \
    --rollkit.aggregator \
    --rollkit.da_auth_token $AUTH_TOKEN \
    --rollkit.da_namespace $DA_NAMESPACE \
    --rollkit.da_start_height $DA_BLOCK_HEIGHT \
    --minimum-gas-prices="0.025stake"

Now, the rollup is running and posting blocks (aggregated in batches) to Celestia. You can view your rollup by using your namespace or account on Mocha testnet or Mainnet Beta explorers.

🎉 Next steps ​

Congratulations! You've built a local rollup that posts data to Celestia's DA layer. Well done! Now, go forth and build something great! Good luck!