Build a Rollup with Avail DA and OP Stack

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Step 1: Set Up Your Avail Alt DA Server

Before we even touch the OP Stack, we need to get the Avail Alt DA server up and running. This server is the key connection point to Avail’s Data Availability (DA) layer, which Crestal provides for you. Let’s set this up first.

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1.1 Create a New Wallet for Avail DA and Get Test Tokens

If you don’t have a wallet for Avail DA yet, no worries—we’ll get you started right here.

• Install a Wallet Extension: We recommend Subwallet to manage your Avail account.
• Create a New Wallet: Open the wallet extension and create a new account. Make sure to save that seed phrase somewhere safe.
  • Example Avail Address: 5E1qtvznhpcCoPzigNFqS5sqMHxo1VTXmX4YSR9yqCiqWrEg
• Get Avail Test Tokens: Go to the Avail Faucet and paste your new address to get some test tokens.
• Verify Your Tokens: Head over to the Avail Explorer, make sure your wallet is connected, and confirm you’ve received the test tokens.

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1.2 Generate Your Own Avail DA App ID

Next, let’s register your app on Avail DA using an App ID. This ID is like your app’s unique identifier when interacting with the DA layer.

• Go to the Chainstate Explorer: Visit Avail explorer, uncheck the “Include Option” toggle, and click the ”+” next to the method name to fetch all registered App IDs.
• Register Your Own App ID: Follow the official guide to create an App ID for your app.
  • Example App ID:
    • owner: 5E1qtvznhpcCoPzigNFqS5sqMHxo1VTXmX4YSR9yqCiqWrEg
    • id: 135

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1.3 Set Up the Avail Alt DA Server

This server will handle all of your rollup’s data availability.

• Get Node Info: Crestal provides the Avail node for you, so you don’t need to set it up from scratch. Simply follow this guide to get the node details, which will look like this:

  {
    "token": "bea08b5e5ad9938ccd5be3a6379c294dbac724e772c58e9c2e2165ceb92218c0",
    "access_url": "https://avail-turing.service.testnet.crestal.xyz/bea08b5e5ad9938ccd5be3a6379c294dbac724e772c58e9c2e2165ceb92218c0",
    "server_https_url": "https://avail-turing.service.testnet.crestal.xyz",
    "server_web_socket_url": "wss://avail-turing.service.testnet.crestal.xyz"
  }
  

• Clone the Server Repository:

 git clone https://github.com/availproject/avail-alt-da-server.git 

• Start the Server: Navigate to the avail-alt-da-server directory and run the following command:

  ./bin/avail-da-server --addr=localhost --port=8000 \
    --avail.rpc=wss://avail-turing.service.testnet.crestal.xyz \
    --avail.seed="YOUR_WALLET_SEED_PHRASE_HERE" \
    --avail.appid=135
  

  Here’s a breakdown of the command:

  • --addr=localhost --port=8000: Runs the server locally on port 8000.
  • --avail.rpc: This is the URL of the Avail RPC node provided by Crestal.
  • --avail.seed: Use your wallet’s seed phrase here.
  • --avail.appid=135: Replace 135 with your own App ID.

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1.4 Verify the DA Server is Running

After starting the DA server, you should see logs confirming that it’s connected to the Avail network:

INFO [10-17|22:59:06.934] Initializing Alt DA DA server...
INFO [10-17|22:59:06.935] Connecting to wss://avail-turing.service.testnet.crestal.xyz/...
INFO [10-17|22:59:09.534] Started DA Server

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Step 2: Create an Infura Account for the Ethereum Sepolia Node

Now that the DA server is running, you’ll need an Infura account to interact with Ethereum’s Sepolia testnet.

1. Sign Up for Infura: Go to Infura and sign up for a free account.
2. Create a New Project: Select Sepolia as the network.
3. Note Project Details: Note down the Project ID and API Key—you’ll need these to connect your rollup to Sepolia.

Your Sepolia node URL will look like this:

https://sepolia.infura.io/v3/your-infura-project-id

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Step 3: Building the Optimism Adapter Source

Now that the DA server is running, let’s build the adapter source for Optimism. Clone the Optimism repo and build the required components.

git clone https://github.com/ethereum-optimism/optimism.git
cd optimism
git fetch --tag --all
git checkout v1.9.1
git submodule update --init --recursive
pnpm install
make op-node op-batcher op-proposer
make build

With these commands, you’ll have the OP stack components (node, batcher, proposer) ready to go for your rollup.

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Step 4: Building Geth

This will help with syncing your rollup chain.

git clone https://github.com/ethereum-optimism/op-geth.git
cd op-geth
git fetch --tag --all
git checkout v1.101408.0
make geth

If you’re using brew to install Go, you’ll want to update the GORUN variable in the Makefile:

GORUN = /opt/homebrew/opt/go@1.22/bin/go run

This ensures your Go environment is properly set up.

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Step 5: Generating and Securing Keys

Generate the keys for your rollup roles: Admin, Proposer, Batcher, and Sequencer.

cd packages/contracts-bedrock
echo "Admin:"; cast wallet new
echo "Proposer:"; cast wallet new
echo "Batcher:"; cast wallet new
echo "Sequencer:"; cast wallet new

Example output for the Admin key:

Address: 0x879b4D04927304A3D383fC4F7b6Fe139053660dA
Private key: 0x9ef007ab575cd12aaeac661fb6f2c7b36a33a7e6a174f3f038015b76e58063bd

Make sure to save all the keys somewhere safe.

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Step 6: Configuring Crestal’s Avail Node

Configure the environment to connect to Crestal’s Avail DA node. Create a .envrc file and add these variables:

# Admin account
export GS_ADMIN_ADDRESS=0xF5E8ce0C00F09Dd70Da27D0e9705E37A56c0d99F
export GS_ADMIN_PRIVATE_KEY=0x929de22a260c8ad100a054b2caf4e5f95f16c13cb5489a7b69f5c96caf1c9205

# Batcher account
export GS_BATCHER_ADDRESS=0x0b31383D636a965878E144b92Da1559d27D26b10
export GS_BATCHER_PRIVATE_KEY=0x292fb38aaa0ffc6e45494242406270e2f90827da170b27657e0df1edd888d211

# Proposer account
export GS_PROPOSER_ADDRESS=0x7Eca23cA2800A3F3D04232d6DA9F091e892C7D1F
export GS_PROPOSER_PRIVATE_KEY=0x0380b7e2b073bc8ce0a070d10b8d5e4a910514b43be2678d3b1c83d21a67f8a8

# Sequencer account
export GS_SEQUENCER_ADDRESS=0x40D1B9CC808Fd2142Ec995dE199879e84fD684DE
export GS_SEQUENCER_PRIVATE_KEY=0x67bdf03337224ccd1aaaa325a1ae407252fd551058e55188a5c7cfbcf8f18cbd

# L1 chain information
export L1_CHAIN_ID=11155111
export L1_BLOCK_TIME=12

# L2 chain information
export L2_CHAIN_ID=42069
export L2_BLOCK_TIME=2
export L1_RPC_KIND=infura

export L1_RPC_URL=wss://sepolia.infura.io/ws/v3/e4603e373f8a4a828a3b9b000f632a78

Activate the environment:

direnv allow .

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Step 7: Deploying Contracts

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7.1 Generate Deployment Config

Head over to the packages/contracts-bedrock directory and run:

./scripts/getting-started/config.sh

This generates a file called getting_started.json in the deploy-config folder.

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7.2 Update the Configuration

Open the getting_started.json file and add this at the bottom:

{
  "useAltDA": true,
  "daCommitmentType": "GenericCommitment",
  "daChallengeWindow": 160,
  "daResolveWindow": 160,
  "daBondSize": 1000000,
  "daResolverRefundPercentage": 0
}

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7.3 Deploy Your Contracts

Run the following command in the packages/contracts-bedrock directory:

DEPLOYMENT_OUTFILE=deployments/artifact.json \
DEPLOY_CONFIG_PATH=deploy-config/getting-started.json \
forge script scripts/deploy/Deploy.s.sol:Deploy --broadcast --private-key $GS_ADMIN_PRIVATE_KEY --rpc-url $L1_RPC_URL --slow

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Step 8: Running the Rollup Components

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8.1 Run Geth

cd ~/Desktop/op-geth
mkdir datadir
build/bin/geth init --datadir=datadir --state.scheme=hash genesis.json
./build/bin/geth \
  --datadir ./datadir \
  --http \
  --http.corsdomain="*" \
  --http.vhosts="*" \
  --http.addr=0.0.0.0 \
  --http.port=9545 \
  --http.api=web3,debug,eth,txpool,net,engine \
  --ws \
  --ws.addr=0.0.0.0 \
  --ws.port=9546 \
  --ws.origins="*" \
  --ws.api=debug,eth,txpool,net,engine \
  --syncmode=full \
  --nodiscover \
  --maxpeers=0 \
  --networkid=42069 \
  --authrpc.vhosts="*" \
  --authrpc.addr=0.0.0.0 \
  --authrpc.port=9551 \
  --authrpc.jwtsecret=./jwt.txt \
  --rollup.disabletxpoolgossip=true \
  --state.scheme=hash \
  --cache=2048

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8.2 Run the OP Node

cd ~/Desktop/optimism/op-node
./bin/op-node \
  --l2=http://localhost:9551 \
  --l2.jwt-secret=./jwt.txt \
  --sequencer.enabled \
  --sequencer.l1-confs=5 \
  --verifier.l1-confs=4 \
  --rollup.config=./rollup.json \
  --rpc.addr=0.0.0.0 \
  --rpc.port=8547 \
  --p2p.disable \
  --rpc.enable-admin \
  --l1=$L1_RPC_URL \
  --altda.enabled=true \
  --altda.da-server=http://localhost:8000

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8.3 Run the OP Batcher

cd ~/Desktop/optimism/op-batcher
./bin/op-batcher \
  --l2-eth-rpc=http://localhost:9545 \
  --rollup-rpc=http://localhost:8547 \
  --poll-interval=1s \
  --private-key=$GS_BATCHER_PRIVATE_KEY \
  --altda.enabled=true \
  --altda.da-server=http://localhost:8000

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8.4 Run the OP Proposer

Grab the L2OutputOracleProxy address from your [chain-id]-deploy.json file, located at packages/contracts-bedrock/deployments.

Now run the OP Proposer:

cd ~/Desktop/optimism/op-proposer
./bin/op-proposer \
  --rollup-rpc=http://localhost:8547 \
  --l2oo-address=0xb7236d31C0819DA796AD106e0A85922F20Dd5b53 \
  --private-key=$GS_PROPOSER_PRIVATE_KEY \
  --l1-eth-rpc=$L1_RPC_URL

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Step 9: Adding Your Rollup Network to the Wallet

Finally, add your custom rollup to a wallet like MetaMask and start playing with your new network!