Deploy spin-operator

spin-operator consists of an Express.js server that accepts player submission and then relay the submission to the blockchain.

Fill in the environments

Create a new file .env and use .env.template as example to fill it in.

Reference provides details on filling the environments: spin-operator reference

Configure wallets

A note about transaction nonce on EVM

The operator write to the chain in two most common ways. settle a submission and submit a submission. In order to handle concurrent requests from many different players, the operator cannot reliably rely on a single wallet to submit all the transactions on-chain. This is due to each on-chain transaction needs to have an unique nonce to prevent replay attacks. Thus, a good practice is to confirm a transaction is mined, then submit the second one.

One way to scale the operator's concurrency is to let the operator own multiple wallets.

Create a file name wallets.json

wallets.json should expect a list of EVM addresses and their corresponding private keys like so:

# wallets.json
[
  {
    "address": "0xd3405C7CdE4FCb6fe0fc40030Bdbaf1e932e16B8",
    "privateKey": "0x179d6eef0cbfabe4cca44ba92d6ade9357c88649699c52168eaa5b3ae4042b97"
  },
  {
    "address": "0x0EfCa6b908F2D5E285Fd02742585b86DEeC2c917",
    "privateKey": "0x30daa0ec767d98bfb388b40acf9ab1fd8728632bf3bb960b218f75d82846d26b"
  },
  {
    "address": "0x5517883fEcFA80a901844B52845bdb151eeD96Ec",
    "privateKey": "0xa15d064fcf5828ffa1a5ddad87254cb142fc2ba0d2b9067274e065e001bdd687"
  }
  ...
]

Make sure all of the wallets has enough ETH to pay for gas fee.

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Run spin-operator

There're few options running a spin-operator. To quickly run an instance, we recommend direly run the image from docker-hub.

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Run from source

Prerequisite

• Node.js >= 20

Build from source

1. Clone the OPZK repo.

git clone https://github.com/zkspin/opzk.git

1. Install the NPM packages

cd opzk/spin-operator && npm install

1. Fill in .env following instruction from above

Run the server

npm run start

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Run from docker

Prerequisite

• Docker version > 25.0.0

Build the docker image

Pull Image from Dockerhub

We already build a latest image of the spin-operator.

The image is under docker pull zkspin/spin-operator:latest

Build Image Locally

1. Clone the OPZK repo.

git clone https://github.com/zkspin/opzk.git

1. Build the docker image

cd opzk && docker build -t spin-operator .  

Run the server

Make sure you have .env and wallets.json ready

Add the docker run option --network host if your chain RPC is on localhost

Run Image from Dockerhub

docker run --env-file ./.env --mount type=bind,source=./wallets.json,target=/app/wallets.json -t zkspin/spin-operator

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