Skip to main content

Sponsored paymaster

Sponsorship Paymaster Example​

This guide helps you set up a smart account and use SCS’s Sponsorship Paymaster using startale-aa-sdk, @privy-io/react-auth, and viem.

Prerequisites​

Make sure you’ve installed:

yarn add viem startale-aa-sdk @privy-io/react-auth

Also, ensure your app is wrapped in Privy’s PrivyProvider.

Step 1: Connect Privy & Get EOA Wallet​


import { usePrivy, useWallets } from "@privy-io/react-auth";

const { authenticated } = usePrivy();
const { wallets } = useWallets();

const provider = await wallets[0].getEthereumProvider(); // EOA provider
const address = wallets[0].address

Step 2: Create Smart Account (StartaleSmartAccount)​


import { toStartaleSmartAccount } from "startale-aa-sdk";
import { createWalletClient, custom } from "viem";
import { soneiumMinato } from "viem/chains";

const signer = createWalletClient({
  account: address,
  chain: soneiumMinato,
  transport: custom(provider),
});

const startaleAccount = = await toStartaleSmartAccount({
  signer: walletClient,
  chain: chain,
  transport: http(),
  index: BigInt(0), // Nonce=index for account instance with same EOA signer as controller
});

Step 3: Create Smart Account Client with Sponsorship Paymaster​


import { createSmartAccountClient, createSCSPaymasterClient } from "startale-aa-sdk";

const scsPaymasterClient = createSCSPaymasterClient({
  // Obtain paymaster url from https://portal.scs.startale.com/api-keys 
  transport: http(paymasterUrl) 
});

const smartAccountClient = createSmartAccountClient({
  account: startaleAccount,
  transport: http(BUNDLER_URL),
  client: publicClient, // from `createPublicClient()`
  paymaster: scsPaymasterClient,
  paymasterContext: {
    calculateGasLimits: true,
    paymasterId: "<YOUR_PAYMASTER_ID_FROM_PORTAL_DASHBOARD>",
  },
});

Final Step: Use the Client to Send Transactions​

Once you have smartAccountClient, you can use:

const hash = await smartAccountClient.sendUserOperation({
  calls: [
    {
      to: "<recipient>",
      value: BigInt(0),
      data: "0x", // encoded call data
    }
  ]
});

You can also use modules like Social Recovery or Sessions via startale-aa-sdk.

Notes​

  • paymasterContext.paymasterId is useful for gated gas sponsorship. You can setup policies on the dashboard which gets attached to your paymaster. All you need to pass is the paymasterId
  • Use calculateGasLimits: true to auto-populate missing gas fields.

Quickstart CLI Scripts Example​

For a complete working example, check out the quickstart CLI scripts example code:

Sponsorship paymaster demo