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 Biconomy 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/biconomy/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 :

  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 "Bundlers" tab

  4. The API Key is the string after the chain ID in the test net Bundler's URL

  5. 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_biconomy_api_key_here with your actual Biconomy's API key.

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

Step 3: Install Dependencies

This example demonstrates how to send a simple transaction using ethers.js and the Biconomy Smart Account with the @biconomy/account SDK. 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 smartAccount-init --network=sepolia

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, you can skip the backup process.

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:

{ 
   "accountIndex": 0,
   "chainId": 11155111,
   "rpcUrl": "https://rpc.sepolia.org",
   "bundlerUrl": "https://bundler.biconomy.io/api/v2/11155111/your_api_key_here",
   "biconomyPaymasterUrl": "https://paymaster.biconomy.io/api/v1/11155111/add_your_api_key_here",
   "preferredToken": "",
   "tokenList": []
```
  },
  "_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": 2442
  }
}

Anatomy of the config.json file:

  • accountIndex:specifies the index of the Ethereum account being used.

  • chainId:Identifies the specific Ethereum network (Sepolia testnet).

  • bundlerUrl:Endpoint for Biconomy's bundler service to batch transactions.

  • rpcUrl: Endpoint for interacting with the Ethereum blockchain via JSON-RPC.

  • 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 smartAccount-address

An 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 test net, 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 test net token.

Step 8: Initiate the transfer

The smartAccount 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 smartAccount-transfer --to=<receiver_address_here> --amount=<amount_here>

Step 9: Approve the signature on the paired Mobile Application

  • When transferring the token to any address via this integration, your phone will receive a signature alert notification and a pop-up on your Silent Shard application.

  • Swipe to approve the transaction. Once approved, you will see the signed userOperation object and the transaction hash. This integration is built on top of Biconomy's Quick Start repository👇. For more details check out the docs here

Logosdk-examples/backend-node at v1 · bcnmy/sdk-examplesGitHub

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

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