Duo SDK

Using the CLI version

Getting Started

This page hosts scripts for creating distributed smart contract accounts between your desktop (CLI) and the Silent Shard Mobile Application, featuring CLI commands that demonstrate key functionalities of popular contracts. It serves as a guide for integrating MPC x Account Abstraction into applications.

Clone this repository to get started with the example quickly. Follow the instructions as listed in the repository's README.

In this page, we will take you through a quick setup of the Stackup x SL repository in a CLI.

Step 1: Download

Clone the mpc-account-abstraction-sdk repository to download the scripts. This example is a basic command-line wallet application.

git clone https://github.com/silence-laboratories/mpc-account-abstraction-sdk

Navigate to the cli directory within the cloned repository:

cd packages/stackup/cli

Configuration Setup:

  • Node Version: Ensure you are using Node.js version 18

Set Up the RPC URL

To set up the rpcUrl, create an instance at StackUp:

  1. Create an account or log in if you already have one.

  2. Select the Sepolia network for your instance.

  3. Once the instance is created, navigate to the "Instances" tab.

  4. Copy the API Key for your instance. You will use this API Key in the next step to set environment variables.

Step 2: Setting Up Environment Variables

  1. Create a .env file:

    • In the root of your project, create a new file named .env.

  2. Fill in your API keys in .env:

    • Replace your_stackup_api_key_here with your actual StackUp API key.

    NEXT_PUBLIC_BASE_URL=https://us-central1-mobile-wallet-mm-snap-staging.cloudfunctions.net
API_KEY=your_stackup_api_key_here

Step 3: Install Dependencies

This example uses the userop.js library to build user operations. You can think of it like ethers.js but for ERC-4337. Install it, and all other dependencies.

npm install

Step 4: Using the Silent Shard App

As defined earlier, this setup is between your CLI and the Silent Shard Mobile Application. To interact further with this setup, please install the Silent Shard App

  1. Download the Silent Shard App from

    1. Apple App Store: Link

    2. Google Play Store: Link

  2. Press the "Connect new Account" to initiate the QR scanner on the app to pair with the CLI.

Step 5: Initialising and Distributed Key Generation

Initialize your local configuration by running the following command:

npm run init

A QR code will be generated on your CLI which must be scanned by the QR scanner on your mobile app (refer to Step 4). Note that during the account setup in the init step, the mobile app will ask you to set a password and backup option. For this CLI demo version, please skip all these steps.

Note that the QR code is time-limited, and will expire post 30 seconds of initiation. Upon expiry, you can run the above command again to generate a new QR code

A config.json file will be created. The file will look like this:

{
  "rpcUrl": "https://api.stackup.sh/v1/node/YOUR_API_KEY",
  "paymaster": {
    "rpcUrl": "https://api.stackup.sh/v1/paymaster/YOUR_API_KEY",
    "context": {}
  },
  "_isSigner": true,
  "address": "0xYourAddressHere",
  "public_key": "YourPublicKeyHere",
  "p1KeyShare": {
    "x1": "YourX1Here",
    "public_key": "YourPublicKeyHere",
    "paillier_private_key": {
      "p": "YourPaillierPHere",
      "q": "YourPaillierQHere"
    },
    "paillier_public_key": "YourPaillierPublicKeyHere"
  },
  "keygenResult": {
    "distributedKey": {
      "publicKey": "YourDistributedPublicKeyHere",
      "accountId": 1,
      "keyShareData": {
        "x1": "YourX1Here",
        "public_key": "YourPublicKeyHere",
        "paillier_private_key": {
          "p": "YourPaillierPHere",
          "q": "YourPaillierQHere"
        },
        "paillier_public_key": "YourPaillierPublicKeyHere"
      }
    },
    "elapsedTime": 2977
  }
}

Anatomy of the config.json file:

  • rpcUrl: URL of an ERC-4337 bundler and node

  • paymaster: URL of the Paymaster service you are using and context (optional)

  • keygenResult: Contains the result of the key generation process, including the distributed public key and key share data, along with the elapsed time for the operation.

Step 6: Create an account

Create a counterfactual address by running the command:

npm run simpleAccount address

A SimpleAccount address will be returned. At this point, the Smart Account has not been deployed. ERC-4337 account addresses are deterministic, so you don't need to deploy the contract to know its address.

Step 7: Fund the account

You will now need to deposit the native token of the blockchain you are using into your new Smart Account. Since we are using the sepolia testnet, you will deposit sepolia ETH into the account.

Navigate to a faucet, such as this link . Enter the account address from Step 6 and claim the testnet token.

Step 8: Initiate the transfer

The simpleAccount transfer command allows you to transfer the native token from the smart contract account to any address. It will create a User Operation, sign it, and send it to the Bundler:

npm run simpleAccount transfer --to <address> --amount <eth>

Step 9: Approve the signature on the paired Mobile Application

Note that when transferring the token to any address via this integration, your phone will receive a signature alert notification twice. (This is a quirk of the Stackup SDK. To know more visit here)

You need to swipe right to approve the transaction both times. Once approved, you will see the signed userOperation object and the transaction hash.

The implementation for all commands is located in the simpleAccount directory within the scripts directory. All scripts are built using the following open-source packages:

If you would like to take such an experience into production, check out the Integration and Hosting section

Last updated