This guide will walk you through the process of building a node from source, focusing on the op-node and op-geth implementations. These steps are essential if you want to run a node on a specific architecture or inspect the source code of the node you're running.
What you're going to Build
Rollup Node (op-node)
Responsible for deriving L2 block payloads from L1 data and passing those payloads to the Execution Client.
Analogous to a consensus client in Ethereum.
Execution Client (op-geth)
Executes the block payloads it receives from the Rollup Node.
Exposes the standard JSON-RPC API used by Ethereum developers.
Software Dependencies
git
^2
git --version
go
^1.22.6
go version
node
^20
node --version
just
^1.34
just --version
foundry
^0.2.0
forge --version
make
^4
make --version
Folder Structure
This guide supports running nodes for arbitrary Gelato RaaS chains, both testnets, and mainnets. Feel free to use any folder structure that suits your needs. For the purposes of this documentation, we will use the following structure below:
To communicate with op-node and enable the Engine API, you'll also need to generate a JWT secret file and enable Geth's authenticated RPC endpoint.
To generate the JWT secret, run the following:
cd /path/to/op-rollup-node
openssl rand -hex 32 > jwt.txt
Obtain genesis.json and rollup.json
Log in to your Dashboard.
Download rollup.json (rollup config) and genesis.json (genesis config) by heading to the details section.
Place them in your config/testnet in the op-rollup-node directory
Build the Rollup Node
Clone the Optimism Monorepo:
git clone https://github.com/ethereum-optimism/optimism.git
cd optimism
Check Out the Required Release Tag:
git checkout <name of release tag>
## We use the latest official release tagged in the GitHub repo https://github.com/ethereum-optimism/optimism/releases
## final command
git checkout ddc37daa49558c2fb5c1a92e694eeb7de5942e00
Build op-node:
make build
Build the Execution Client
Clone op-geth:
git clone https://github.com/ethereum-optimism/op-geth.git
cd op-geth
Check Out the Required Release Tag:
git checkout <name of release tag>
##We use the latest official release tagged in the GitHub repo https://github.com/ethereum-optimism/op-geth/releases
git checkout 7c2819836018bfe0ca07c4e4955754834ffad4e0
Build op-geth:
make geth
Running op-geth
Create a Data directory in your op-geth
cd /path/to/op-rollup-node/op-geth
mkdir data-geth
cd /path/to/op-rollup-node/op-geth
nano init-geth.sh
#!/bin/bash
# Set environment variables
source .env
# Create data directory if it doesn't exist
mkdir -p $DATADIR_PATH
# Initialize geth with the genesis file
echo "Initializing geth with genesis file..."
./build/bin/geth --datadir=$DATADIR_PATH init $GENESIS_PATH
# Generate JWT secret if it doesn't exist
if [ ! -f "$JWT_SECRET_PATH" ]; then
echo "Generating JWT secret..."
openssl rand -hex 32 > $JWT_SECRET_PATH
fi
Run the geth Node
cd /path/to/op-rollup-node/op-geth
# Load environment variables from the .env file in the root directory
source .env
# Initialize geth
./init-geth.sh
# Run the geth command with the environment variables
./build/bin/geth
Testing the Running Geth Instance
After starting your geth instance, you can use the following bash script to test if geth is running and to confirm the chain ID:
curl -X POST http://127.0.0.1:8545 \
-H "Content-Type: application/json" \
--data '{"method":"eth_chainId","params":[],"id":1,"jsonrpc":"2.0"}'
##You should see a response similar to this
{
"jsonrpc": "2.0",
"id": 1,
"result": "0x2a88" ##This is your chain id in hex, in this case its 10888.
}
Ensure that op-node P2P ports (<EXTERNAL_P2P_TCP_PORT> and <EXTERNAL_P2P_UDP_PORT>) are accessible externally via <EXTERNAL_P2P_IP>. This allows the node to communicate with other peers on the network.
Add the sequencer node's multiaddr to <STATIC_PEERS> in your configuration. This helps establish a direct connection with the sequencer, ensuring smooth operation and synchronization.
Run the op-node
cd /path/to/op-rollup-node/optimism
# Load environment variables from the .env file in the root directory
source .env
# Run the op-node command with the environment variables
./op-node/bin/op-node
Feel free to customize the base configurations provided in the Optimism documentation to suit your specific requirements. While we will use the recommended configurations for this guide, you can explore and add additional flags as needed. Detailed information about execution layer configurations can be found .
We will utilize the base configurations provided in the Optimism documentation for the consensus layer. However, you can adjust and expand these configurations to fit your specific requirements. For a comprehensive understanding of all available configurations, refer to the detailed documentation on consensus layer configurations .
