Setting up a Relayer

To configure the relayer, we will go through the following steps:

• Installing Dependencies
• Installing the Relayer
• Configuring the Relayer
  • Private key
  • RPCs
  • NODE_ENV
• Running the relayer

Installing Dependencies

The only dependencies for the relayer are Docker and Docker Compose Plugin (≥v2.24.0). You can find the installation instructions here:

https://docs.docker.com/engine/install/#supported-platforms

Click on the operation system of choice. We recommend Ubuntu and follow the relevant instructions like “Install using the apt repository”.

Before going further, check if you have Docker installed, run:

docker compose version

It should return: Docker Compose version v2.24.7 or similar. If it returns a version lower than v2.24.0 or an error, you have done something wrong.

Installing the Relayer

To install the relayer, pull the generalised-relayer repository.

git clone https://github.com/catalystdao/generalised-relayer.git
cd generalised-relayer

We also need to make two copies of the configuration files.

cp config.example.yaml config.production.yaml
cp .env.example .env

Once this has been done, we can go on to configuration.

Configuring the Relayer

We need to edit config.production.yaml with the correct configuration values. Assuming that you initially just want to dip your toes into relaying Generalised Incentives messages, you only have to set global.privateKey and RPCs (chains.[chain].rpc).

Private key

This is a sensitive operation. You will have to generate a private key that will hold the gas for the relayer and relaying rewards. If someone else gets access to this key, they can steal your funds!

For this tutorial we will use Foundry to give us a new address, however, Metamask is also suitable. Using Foundry: cast wallet new will produce an output like:

Successfully created new keypair.
Address:     <YOUR_ADDRESS>
Private key: <YOUR_PRIVATE_KEY>

If you haven’t installed Foundry, this command will not work. Instead, use Metamask.

Remember to backup your private key. After backing up your private key add it to the config. It is line number 2:

nano config.production.yaml

It should look something like:

global:
  privateKey: '0xf2d04...2369'
  logLevel: 'info'
  blockDelay: 1
  ...

where 0xf2d04...23d9 is your privatekey.

Private Key Format

A proper private key begins with 0x. Metamask does not add 0x to the front of the privatekey and you may have to do that yourself. The privatekey should be 64 characters long without 0x and 66 characters long with 0x.

Caution

Do not use this private key for other applications as it could interfere with the operation of the relayer wallet. Use a dedicated private key for the relayer to ensure proper operation.

RPCs

The relayer comes with default public RPCs, however, these are not competitive, stable, or likely to continue working. By default, the config also contains a lot of chains. You may want to disable some chains depending on your preference.

We recommend an RPC service like Alchemy. If you make an account with Alchemy, you can also get funds for a testnet deployment from their faucets: https://www.alchemy.com/faucets/ethereum-sepolia

Edit the config with your chain configuration, they can be found at the bottom.

nano config.production.yaml

It should look something like this:

...
chains:
  - chainId: 11155111
    name: "Sepolia"
    rpc: "<SEPOLIA_RPC>"
    ...

  - chainId: 421614
    name: "Arbitrum Sepolia"
    rpc: "<ARB_SEPOLIA_RPC>"
    ...

  - chainId: 11155420
    name: "OP Sepolia"
    rpc: "<OP_SEPOLIA_RPC>"
    ...

  - chainId: 84532
    name: "Base Sepolia"
    rpc: "<BASE_SEPOLIA_RPC>"
    ...

NODE_ENV

The relayer chooses the configuration file based on the env. variable NODE_ENV. So far we have worked with the configuration being named config.production.yaml. As a result, we need to set NODE_ENV appropriately. This is done by running:

export NODE_ENV=production

For simplicity, you can set NODE_ENV across sessions. If you use this machine for other projects don’t do this.

echo "export NODE_ENV=production" >> ~/.bashrc

Running the relayer

When everything has been set, assuming you are within the relayer folder, ~/generalised-relayer, you can start the relayer by running:

docker compose up -d

You can access the log by running:

docker compose logs relayer -fn 100

If you want to stop the relayer you can run

docker compose stop