DFNS

Dfns provides wallet-as-a-service infrastructure that enables crypto developers to forget about private key management so they can focus on building what matters most — their applications. This guide will show you how to create a smart account using DFNS as a signer.

tip

Check out an end-to-end integration of DFNS with Biconomy on this repo!

Before using the code in this guide you will need to onboard onto DFNS, check out their onboarding guide here.

Code snippets below will be taken from the repository mentioned above and include some environment variables you will be able to fill in. The example will follow a node js script but can be adopted for frontend frameworks as well.

The first thing we need to do is generate a DFNS wallet. Let's take a look at the imports and then the code for generating the wallet.

Imports

import {
  BiconomySmartAccountV2,
  DEFAULT_ENTRYPOINT_ADDRESS,
} from "@biconomy/account";
import { Bundler } from "@biconomy/bundler";
import {
  DEFAULT_ECDSA_OWNERSHIP_MODULE,
  ECDSAOwnershipValidationModule,
} from "@biconomy/modules";
import { BiconomyPaymaster, PaymasterMode } from "@biconomy/paymaster";
import { DfnsWallet } from "@dfns/lib-ethersjs5";
import { DfnsApiClient } from "@dfns/sdk";
import { AsymmetricKeySigner } from "@dfns/sdk-keysigner";
import { Interface } from "@ethersproject/abi";
import { JsonRpcProvider } from "@ethersproject/providers";
import dotenv from "dotenv";

dotenv.config();

Generate DFNS Wallet

const provider = new JsonRpcProvider(process.env.POLYGON_PROVIDER_URL);

const initDfnsWallet = (walletId: string, provider: JsonRpcProvider) => {
  const signer = new AsymmetricKeySigner({
    privateKey: process.env.DFNS_PRIVATE_KEY!,
    credId: process.env.DFNS_CRED_ID!,
    appOrigin: process.env.DFNS_APP_ORIGIN!,
  });

  const dfnsClient = new DfnsApiClient({
    appId: process.env.DFNS_APP_ID!,
    authToken: process.env.DFNS_AUTH_TOKEN!,
    baseUrl: process.env.DFNS_API_URL!,
    signer,
  });

  return new DfnsWallet({
    walletId,
    dfnsClient,
    maxRetries: 10,
  }).connect(provider);
};

const amoyWallet = initDfnsWallet(process.env.POLYGON_WALLET_ID!, provider);

Remember to get your API keys from the DFNS dashboard and follow their getting started guides for this part of the process.

Create Smart Account

const bundler = new Bundler({
  bundlerUrl: "",
  chainId: 80002,
  entryPointAddress: DEFAULT_ENTRYPOINT_ADDRESS,
});

const paymaster = new BiconomyPaymaster({
  paymasterUrl: "",
});

const createAccount = async (): Promise<BiconomySmartAccountV2> => {
  const module = await ECDSAOwnershipValidationModule.create({
    signer: amoyWallet,
    moduleAddress: DEFAULT_ECDSA_OWNERSHIP_MODULE,
  });

  return BiconomySmartAccountV2.create({
    chainId: 80002,
    bundler: bundler,
    paymaster: paymaster,
    entryPointAddress: DEFAULT_ENTRYPOINT_ADDRESS,
    defaultValidationModule: module,
    activeValidationModule: module,
  });
};

You can get all paymaster and bundler URLs from your Biconomy Dashboard for this step.

With this integration you will have everything you need to begin using the Biconomy Smart Account with DFNS. Remember to check out the full integration here to see this in action with an example that includes executing a gasless transaction as well.