Building your first Micro-Rollup

Setup up your first Micro-Rollup and take it for a spin in just 5 easy steps

1. Initialize new project

Using the Stackr-CLI you can initialize a new Micro-Rollup project.

stackr init --project-name counter

This will create a new folder called counter and initialize a new Micro-Rollup project inside of it. By default the project will be initialized with a template that includes a simple counter.

You will notice typescript throwing some missing file errors, Don’t worry this will be taken care of in the next steps

You might need to do npm install sqlite3 in the rollup directory after the previous step because for some odd reason bun doesn’t install it properly

2. Checkout stackr.config.ts

The stackr.config.ts file is the main configuration file for your Micro-Rollup. It contains rollup’s operational information like app inbox, block time, block size, verification delay etc. It also contains the app’s domain which will be used for EIP-712 signing of the actions.

• Update the private key

This private key is the operator’s private key. This is the key that will be used to sign the rollup blocks. This key is also used to deploy the rollup inbox contract and genesis state.

Add a private key which has some funds in it.

stackr.config.ts

operator: {
    accounts: [
      {
        privateKey: "<OPERATOR_KEY>",
        purpose: KeyPurpose.BATCH,
        scheme: SignatureScheme.ECDSA,
      },
    ],
  },

• Update the EIP-712 domain

Stackr uses EIP-712 for signing the actions. The domain is used to generate the domain separator for the EIP-712 signing. You can learn more about EIP-712 here.

stackr.config.ts

domain: {
    name: "<YOUR_APP_NAME>",
    version: "<APP_VERSION>",
    chainId: "<CHAIN_ID>", // use 42069 for testnet
    verifyingContract: deployment.app_inbox, // this is the app inbox contract address generated in the next step
    salt: "0x0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef", // this is a random salt
  }

3. Register your micro-rollup to Stackr’s on-chain registry

stackr register

This command will register your micro-rollup to Stackr’s on-chain registry. Essentially this deploys a new rollup inbox contract for your rollup where the rollup’s transaction data will go and also generate an app-id for your micro-rollup. The app-id and the app inbox contract addresses are stored in deployment.json file which is used by the config.

Make sure that the private key you entered has sufficient funds to cover the deployment of the contracts

This will create a deployment.json file in the root of your project that looks like this

{ "app_id": 1, "app_inbox": "0xa16e02e87b7454126e5e10d957a927a7f5b5d2be" }

4. Compile your micro-rollup

stackr compile

This command will compile your micro-rollup by parsing the state and the state transition function and putting it all into an executable WASM binary inside the build folder.

(This step is kinda boring from outside NGL, but the most technically impressive one behind the scenes, like seriously TS -> WASM in one step? Are ya kidding me?)

5. Deploy your micro-rollup

stackr deploy

This is the most exciting step. This command is similar to deploying a smart contract bytecode to Ethereum but over here the State machine goes to Vulcan and the the attestation to genesis state and the code logic goes on Ethereum.

That’s it!

You have successfully deployed your first micro-rollup.